Atomix - User contributions [en]

Benchmark datasets for shear probes

2024-05-22T07:37:17Z

Ilker:

We compiled a collection of five benchmark data sets described in Scientific Data: [https://www.nature.com/articles/s41597-024-03323-y Fer et al. (2024)]

These datasets can be accessed from the BODC center.

We provide a number of Matlab routines to read in and compare data from grouped NetCDF files that follow our recommended structure on our [https://github.com/SCOR-ATOMIX/shear-probes GitHub repository]. The Matlab function ATOMIX_load.m there can be used to load a benchmark data file.

{| class="wikitable sortable"
|-
! Link
! Region
! Instrument
! Platform
! PI (ATOMIX)
! Comment
|-
| [https://doi.org/10.5285/0ec16a65-abdf-2822-e063-6c86abc06533]
| Haro Strait
| VMP-250
| Ship
| Lueck
| Intense turbulence. Large up/down drafts. Most estimates require fitting to the inertial subrange.
|-
| [https://doi.org/10.5285/0ebffc86-ed32-5dde-e063-6c86abc08b3a]
| Rockall Trough
| Epsilometer
| Ship
| Le Boyer
| Strong turbulence in a canyon
|-
| [https://doi.org/10.5285/05f21d1d-bf9c-5549-e063-6c86abc0b846]
| Faroe Bank Channel (North Atlantic)
| VMP-2000
| Ship
| Fer
| Ranging from quiescent mid-water to turbulent, deep gravity current
|-
| [https://doi.org/10.5285/0e35f96f-57e3-540b-e063-6c86abc06660]
| Baltic Sea
| MSS
| Ship
| Holtermann
|
|-
| [https://doi.org/10.5285/0ec17274-7a64-2b28-e063-6c86abc0ee02]
| Minas Passage (Bay of Fundy, NS)
| MicroRider
| Mooring
| Lueck
| A swift tidal channel. All dissipation estimated from the inertial subrange
|-
|}

[[Category: Shear probes]]

-------------------------
return to [[Shear probes]] <br><br>
ATOMIX members: see also [[Tentative benchmarks for shear probes| tentative benchmarks for testers]]

Benchmark datasets for shear probes

2024-05-22T07:35:33Z

Ilker:

We compiled a collection of five benchmark data sets described in Scientific Data: [https://www.nature.com/articles/s41597-024-03323-y Fer et al. (2024)]

These datasets can be accessed from the BODC center.

We provide a number of Matlab routines to read in and compare data from grouped NetCDF files that follow our recommended structure on our [https://github.com/SCOR-ATOMIX/shear-probes GitHub repository]. The Matlab function ATOMIX_load.m there can be used to load a benchmark data file.

{| class="wikitable sortable"
|-
! Link
! Platform
! Instrument
! Region
! PI (ATOMIX)
! Comment
|-
| [https://doi.org/10.5285/0ec16a65-abdf-2822-e063-6c86abc06533]
| Ship
| VMP-250
| Haro Strait
| Lueck
| Intense turbulence. Large up/down drafts. Most estimates require fitting to the inertial subrange.
|-
| [https://doi.org/10.5285/0ebffc86-ed32-5dde-e063-6c86abc08b3a]
| Ship
| Epsilometer
| Rockall Trough
| Le Boyer
| Strong turbulence in a canyon
|-
| [https://doi.org/10.5285/05f21d1d-bf9c-5549-e063-6c86abc0b846]
| Ship
| VMP-2000
| Faroe Bank Channel (North Atlantic)
| Fer
| Ranging from quiescent mid-water to turbulent, deep gravity current
|-
| [https://doi.org/10.5285/0e35f96f-57e3-540b-e063-6c86abc06660]
| Ship
| MSS
| Baltic Sea
| Holtermann
|
|-
| [https://doi.org/10.5285/0ec17274-7a64-2b28-e063-6c86abc0ee02]
| Mooring
| MicroRider
| Minas Passage (Bay of Fundy, NS)
| Lueck
| A swift tidal channel. All dissipation estimated from the inertial subrange
|-
|}

[[Category: Shear probes]]

-------------------------
return to [[Shear probes]] <br><br>
ATOMIX members: see also [[Tentative benchmarks for shear probes| tentative benchmarks for testers]]

Shear probes

2024-05-22T07:28:18Z

Ilker:

== Welcome to the shear probe group! ==

The shear probe group addresses best practices in obtaining dissipation rate estimates from shear probes using a platform-independent approach. Our recommendations are applicable for measurements from probes attached to e.g., conventional gravity-driven loose-tether vertical profilers, ocean gliders, autonomous underwater vehicles (AUVs), or autonomous self-propelled floats (e.g. SOLO).

Our "Best practices recommendations for estimating dissipation rates from shear probes" are described in a Methods article in Frontiers in Marine Science: [https://www.frontiersin.org/articles/10.3389/fmars.2024.1334327/full Lueck et al. (2024)]

We compiled a collection of five benchmark datasets described in Scientific Data: [https://www.nature.com/articles/s41597-024-03323-y Fer et al. (2024)]

== Scope ==

The shear probe group provides the following:

{|class="wikitable" style="margin-left: auto; margin-right: auto; border: none; text-align:center;"
|[[File:Flowchart symbol.png|180px|link=Flow chart for shear probes|Flow chart for shear probes]]
|[[File:M Rider Glider 1.JPG|250px|link=Dataset requirements for shear probes|Dataset requirements for shear probes]]
|[[File:MSS ADCP CTD (Schaffer).JPG|250px|link=Tentative benchmarks for shear probes|Benchmark datasets for shear probes]]
|-
|[[Flow chart for shear probes|Flow chart for <br>data processing]]
|[[Dataset requirements for shear probes | Dataset requirements <br>and format description]]
|[[Benchmark datasets for shear probes | Benchmark <br>datasets]]
|}

[[Category: Shear probes]]

-----
Return [[Main Page]]

Shear probes

2024-05-22T07:28:00Z

Ilker:

== Welcome to the shear probe group! ==

The shear probe group addresses best practices in obtaining dissipation rate estimates from shear probes using a platform-independent approach. Our recommendations are applicable for measurements from probes attached to e.g., conventional gravity-driven loose-tether vertical profilers, ocean gliders, autonomous underwater vehicles (AUVs), or autonomous self-propelled floats (e.g. SOLO).

Our "Best practices recommendations for estimating dissipation rates from shear probes" are described in a Methods article in Frontiers in Marine Science: [https://www.frontiersin.org/articles/10.3389/fmars.2024.1334327/full Lueck et al. (2024)]

We compiled a collection of five benchmark data sets described in Scientific Data: [https://www.nature.com/articles/s41597-024-03323-y Fer et al. (2024)]

== Scope ==

The shear probe group provides the following:

{|class="wikitable" style="margin-left: auto; margin-right: auto; border: none; text-align:center;"
|[[File:Flowchart symbol.png|180px|link=Flow chart for shear probes|Flow chart for shear probes]]
|[[File:M Rider Glider 1.JPG|250px|link=Dataset requirements for shear probes|Dataset requirements for shear probes]]
|[[File:MSS ADCP CTD (Schaffer).JPG|250px|link=Tentative benchmarks for shear probes|Benchmark datasets for shear probes]]
|-
|[[Flow chart for shear probes|Flow chart for <br>data processing]]
|[[Dataset requirements for shear probes | Dataset requirements <br>and format description]]
|[[Benchmark datasets for shear probes | Benchmark <br>datasets]]
|}

[[Category: Shear probes]]

-----
Return [[Main Page]]

Level 4 data (shear probes)

2024-05-08T11:16:32Z

Ilker:

Level 4 data include the final dissipation estimates as time series, as well as indicators for the quality and accuracy of the estimates and additional derived parameters. It is saved in the NetCDF group "L4_dissipation". Each dissipation estimate in level 4 corresponds to a spectrum in the level 3 data. Consequently, the level 3 and 4 TIME dimensions are the same. Parameter EPSI_FINAL is the final dissipation rate estimate, averaged of the selected estimates (using the [[Quality_control_coding | QC flags]]) at that depth.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|}
</div>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimensions
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^c</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section _of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA ||
|-
| EPSI || specific_turbulent_kinetic_energy_dissipation _in_water || W kg-1 || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_FINAL || specific_turbulent_kinetic_energy_dissipation _in_water || W kg-1 || TIME_SPECTRA
|-
| KMIN || minimum_wavenumber_used_for_estimating_ turbulent_kinetic_energy_dissipation || cpm ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| KMAX || maximum_wavenumber_used_for_estimating_ turbulent_kinetic_energy_dissipation || cpm || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| N_S || number_of_spectral_points_used_for_estimating_turbulent_kinetic_energy_dissipation || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_STD || expected_standard_deviation_of_the_ logarithm_of_the_dissipation_estimate || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_FLAGS <math>^a</math> || dissipation_qc_flags || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| METHOD <math>^b</math>|| method_used_for_estimating_ turbulent_kinetic_energy_dissipation || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|}
<math>^a</math> [[Quality_control_coding | Quality control coding]] for the final dissipation estimate.

<math>^b</math> METHOD=0 for spectral integration, METHOD=1 for fitting to the inertial subrange.

<math>^c</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
</div>

=Optional Level 4 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| KVISC || kinematic_viscosity_of_water || m2 s-1 || TIME_SPECTRA
|-
| FOM || figure_of_merit || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| MAD || mean_absolute_deviation || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| VAR_RESOLVED || variance_resolved || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| DESPIKE_FRACTION_SH || fraction_of_shear_data_modified_by_despiking_algorithm || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| DESPIKE_PASS_COUNT_SH || number_of_despike_passes_for_shear_probes || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|}

</div>

-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 3 data (shear probes)| Level 3 data]].
[[Category:Shear probes]]

Netcdf meta data (shear probes)

2024-05-08T11:06:27Z

Ilker: /* Required Metadata */

<br>
Below we list the metadata '''required''' in a NetCDF data file, as well as the optional meta data we '''highly recommend''' that are included with the data set.

The parameter names should be used as listed (attention to underscores). The descriptions are example text or several options that are available for that parameter.

=Required Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
|title || E.g., Vertical micostructure profiler data from cruise XXX
|-
|authors || Names of authors
|-
|summary || An abstract describing the dataset
|-
|comment|| Supplementary technical details about the collecting and processing of the dataset
|-
|platform || The platform from which the data are collected. From the SeaVoX Platform Categories (L06) list,
e.g. sub-surface mooring, research vessel, sub-surface glider
|-
|source || The instrument used for collecting the data. For example, vertical microstructure profiler, VMP2000 SN009.
|-
|date_created || The date on which the data was created, yyyy-mm-ddTHH:MM:SSZ
|-
|date_modified || The date on which the data was last modified, yyyy-mm-ddTHH:MM:SSZ
|-
|time_reference_year || Year for time reference
|-
|time_coverage_start || Time of the first data point in the dataset, yyyy-mm-ddTHH:MM:SSZ
|-
|time_coverage_end || Time of thelast data point in the dataset, yyyy-mm-ddTHH:MM:SSZ
|-
|geospatial_lat_min || Southern bound of data, decimal degrees, negative for South
|-
|geospatial_lat_max || Northern bound of data, decimal degrees, negative for South
|-
|geospatial_lon_min || Western bound of data, decimal degrees, negative for West
|-
|geospatial_lon_max || Eastern bound of data, decimal degrees, negative for West
|-
| fs_fast || Sampling frequency for fast (turbulence) channels
|-
| fs_slow <math>^a</math> || Sampling frequency for slow channels (if exist)
|-
| profiling_direction || E.g., horizontal, vertical, or glide
|-
| fft_length || Length of the Fast Fourier transform segments (in data points; note, fft_lengths_sec in seconds is optional)
|-
| diss_length || Length of data (in data points) used for each dissipation estimate
|-
| overlap || Length of overlap (in data points) in diss_length
|-
| goodman || Vibration coherent noise removal using the Goodman algorithm. 0=not applied; 1=applied
|-
| HP_cut || The high-pass filter cutoff frequency in Hz. Can be zero for no filtering.
|-
| conventions || A comma-separated list of the conventions that are followed by the dataset. e.g., CF-1.6, ACDD-1.3, ATOMIX
|-
| history || Provides an audit trail for modifications to the original data; e.g., Version 1
|}
<math>^a</math> or fs_ctd or similar if such records are included
</div>

=Optional Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
| fft_length_sec || seconds
|-
| diss_length_sec || seconds
|-
| overlap_sec || (for diss_length_sec) seconds
|-
| f_AA || Hz, the anti-aliasing frequency.
|-
| FOM_limit || non-dimensional, if absent the FOM QC-flag is not set. Typically, 1.15. It can be as large as 1.4.
|-
| diss_ratio_limit || non-dimensional, if absent the dissipation ration QC-flag is not set. Typically, 2.77.
|-
| despike_shear_fraction_limit || non-dimensional, if absent the de-spike fraction QC-flag is not set. Typically, 0.05.
|-
| despike_shear_iterations_limit || non-dimensional, if absent the de-spike iteration passes QC-flag is not set. Typically 8.
|-
| variance_resolved_limit || threshold for the minimum percent of variance resolved in a shear spectrum. Typically 50%.
|-
| spectral_model || e.g., Nasmyth, Lueck or Panchev-Kesich
|-
| spectrum_std || statistical uncertainty (standard deviation) of the natural logarithm of spectrum of shear
|-
| num_vibration_goodman || number of vibration or acceleration time series used to clean the shear spectrum
|-
| f_limit || upper limit to exclude frequencies that have contaminations. Typically infinity.
|-
| fit_2_isr || dissipation threshold to use the method of fitting to the inertial subrange. Typically 10-5 W/kg.
|-
|eps_remove_top_meters || if applicable, upper meters removed from dissipation estimates (e.g., because of ship)
|-
|area || e.g., Arctic Ocean, Barents Sea
|-
|geospatial_vertical_min|| 0
|-
|geospatial_vertical_max|| in m
|-
|geospatial_vertical_positive|| down, up
|-
|institution || e.g. University of Bergen
|-
|principal_investigator || Name of Principal Investigator
|-
|contact || email address of corresponding author (usually principal investigator)
|-
|project || name of project for which the data was collected
|-
|cruise || name of cruise from which the data was collected
|-
|vessel || name of vessel from which the data was collected
|-
|source || From the SeaVoX Platform Categories vocabulary (L06) list, e.g. “subsurface mooring”, ”ship”, ""sub-surface gliders"", ""autonomous underwater vehicle"" (CF)
|-
|references || key references
|-
|keywords || relevant keywords describing data e.g. shear probes
|-
|creator_name || name of person who generated the file
|-
|creator_email || email address of person who generated the file
|-
|creator_url || website address of the creator
|-
|acknowledgement|| acknowledgements for this data. e.g. this could include crew of ship or funders
|-
|station_name || name of station
|-
|license || the URL to a standard or specific license,
e.g, http://creativecommons.org/licenses/by/4.0/, Freely Distributed, or None
|}

</div>

return to [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Shear probes

2024-05-02T07:42:14Z

Ilker:

== Welcome to the shear probe group! ==

The shear probe group addresses best practices in obtaining dissipation rate estimates from shear probes using a platform-independent approach. Our recommendations are applicable for measurements from probes attached to e.g., conventional gravity-driven loose-tether vertical profilers, ocean gliders, autonomous underwater vehicles (AUVs), or autonomous self-propelled floats (e.g. SOLO).

Our "Best practices recommendations for estimating dissipation rates from shear probes" are described in a Methods article in Frontiers in Marine Science: [https://www.frontiersin.org/articles/10.3389/fmars.2024.1334327/full Lueck et al. (2024)]
== Scope ==

The shear probe group provides the following:

{|class="wikitable" style="margin-left: auto; margin-right: auto; border: none; text-align:center;"
|[[File:Flowchart symbol.png|180px|link=Flow chart for shear probes|Flow chart for shear probes]]
|[[File:M Rider Glider 1.JPG|250px|link=Dataset requirements for shear probes|Dataset requirements for shear probes]]
|[[File:MSS ADCP CTD (Schaffer).JPG|250px|link=Tentative benchmarks for shear probes|Benchmark datasets for shear probes]]
|-
|[[Flow chart for shear probes|Flow chart for <br>data processing]]
|[[Dataset requirements for shear probes | Dataset requirements <br>and format description]]
|[[Benchmark datasets for shear probes | Benchmark <br>datasets]]
|}

[[Category: Shear probes]]

-----
Return [[Main Page]]

Netcdf meta data (shear probes)

2024-05-02T07:37:23Z

Ilker:

<br>
Below we list the metadata '''required''' in a NetCDF data file, as well as the optional meta data we '''highly recommend''' that are included with the data set.

The parameter names should be used as listed (attention to underscores). The descriptions are example text or several options that are available for that parameter.

=Required Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
|title || E.g., Vertical micostructure profiler data from cruise XXX
|-
|authors || Names of authors
|-
|summary || An abstract describing the dataset
|-
|comment|| Supplementary technical details about the collecting and processing of the dataset
|-
|platform_type || The platform from which the data are collected. From the SeaVoX Platform Categories (L06) list,
e.g. sub-surface mooring, research vessel, sub-surface glider
|-
|source || The instrument used for collecting the data. For example, vertical microstructure profiler, VMP2000 SN009.
|-
|date_created || The date on which the data was created, yyyy-mm-ddTHH:MM:SSZ
|-
|date_modified || The date on which the data was last modified, yyyy-mm-ddTHH:MM:SSZ
|-
|time_reference_year || Year for time reference
|-
|time_coverage_start || Time of the first data point in the dataset, yyyy-mm-ddTHH:MM:SSZ
|-
|time_coverage_end || Time of thelast data point in the dataset, yyyy-mm-ddTHH:MM:SSZ
|-
|geospatial_lat_min || Southern bound of data, decimal degrees, negative for South
|-
|geospatial_lat_max || Northern bound of data, decimal degrees, negative for South
|-
|geospatial_lon_min || Western bound of data, decimal degrees, negative for West
|-
|geospatial_lon_max || Eastern bound of data, decimal degrees, negative for West
|-
| fs_fast || Sampling frequency for fast (turbulence) channels
|-
| fs_slow <math>^a</math> || Sampling frequency for slow channels (if exist)
|-
| profiling_direction || E.g., horizontal, vertical, or glide
|-
| fft_length || Length of the Fast Fourier transform segments (in data points; note, fft_lengths_sec in seconds is optional)
|-
| diss_length || Length of data (in data points) used for each dissipation estimate
|-
| overlap || Length of overlap (in data points) in diss_length
|-
| goodman || Vibration coherent noise removal using the Goodman algorithm. 0=not applied; 1=applied
|-
| HP_cut || The high-pass filter cutoff frequency in Hz. Can be zero for no filtering.
|-
| conventions || A comma-separated list of the conventions that are followed by the dataset. e.g., CF-1.6, ACDD-1.3, ATOMIX
|-
| history || Provides an audit trail for modifications to the original data; e.g., Version 1
|}
<math>^a</math> or fs_ctd or similar if such records are included
</div>

=Optional Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
| fft_length_sec || seconds
|-
| diss_length_sec || seconds
|-
| overlap_sec || (for diss_length_sec) seconds
|-
| f_AA || Hz, the anti-aliasing frequency.
|-
| FOM_limit || non-dimensional, if absent the FOM QC-flag is not set. Typically, 1.15. It can be as large as 1.4.
|-
| diss_ratio_limit || non-dimensional, if absent the dissipation ration QC-flag is not set. Typically, 2.77.
|-
| despike_shear_fraction_limit || non-dimensional, if absent the de-spike fraction QC-flag is not set. Typically, 0.05.
|-
| despike_shear_iterations_limit || non-dimensional, if absent the de-spike iteration passes QC-flag is not set. Typically 8.
|-
| variance_resolved_limit || threshold for the minimum percent of variance resolved in a shear spectrum. Typically 50%.
|-
| spectral_model || e.g., Nasmyth, Lueck or Panchev-Kesich
|-
| spectrum_std || statistical uncertainty (standard deviation) of the natural logarithm of spectrum of shear
|-
| num_vibration_goodman || number of vibration or acceleration time series used to clean the shear spectrum
|-
| f_limit || upper limit to exclude frequencies that have contaminations. Typically infinity.
|-
| fit_2_isr || dissipation threshold to use the method of fitting to the inertial subrange. Typically 10-5 W/kg.
|-
|eps_remove_top_meters || if applicable, upper meters removed from dissipation estimates (e.g., because of ship)
|-
|area || e.g., Arctic Ocean, Barents Sea
|-
|geospatial_vertical_min|| 0
|-
|geospatial_vertical_max|| in m
|-
|geospatial_vertical_positive|| down, up
|-
|institution || e.g. University of Bergen
|-
|principal_investigator || Name of Principal Investigator
|-
|contact || email address of corresponding author (usually principal investigator)
|-
|project || name of project for which the data was collected
|-
|cruise || name of cruise from which the data was collected
|-
|vessel || name of vessel from which the data was collected
|-
|source || From the SeaVoX Platform Categories vocabulary (L06) list, e.g. “subsurface mooring”, ”ship”, ""sub-surface gliders"", ""autonomous underwater vehicle"" (CF)
|-
|references || key references
|-
|keywords || relevant keywords describing data e.g. shear probes
|-
|creator_name || name of person who generated the file
|-
|creator_email || email address of person who generated the file
|-
|creator_url || website address of the creator
|-
|acknowledgement|| acknowledgements for this data. e.g. this could include crew of ship or funders
|-
|station_name || name of station
|-
|license || the URL to a standard or specific license,
e.g, http://creativecommons.org/licenses/by/4.0/, Freely Distributed, or None
|}

</div>

return to [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Level 1 data (shear probes)

2024-02-01T12:16:11Z

Ilker:

Level 1 data refers to the full resolution data in physical units, e.g. the regularly sampled time series of [[Convert the shear probe data|converted shear probe data]]. If needed, a transfer function for shear is given. Below, a table with parameters included in the level 1 data set is compiled. The parameter names and definitions fit the [[NetCDF parameter]] attributes and data is stored as a NetCDF group with the name "L1_converted".

In the standard names, "sea_water" can be replaced with "water" if working in freshwater environments. This is specified in some entries below but not all.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from the *** sensor (e.g., CTD or SLOW)
|-
|N_SHEAR_SENSORS ||number of shear channel (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Typically we assume TIME for the fast-sampled microstructure channels, and for example, _SLOW or _CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors, <br>
N_ACC_SENSORS for vibration acceleration sensors, <br>
N_GRADT_SENSORS for thermistors, <br>
N_GRADC_SENSORS for microconductivity sensors. <br>
</div>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^a</math> || TIME
|-
| SHEAR || sea_water_velocity_shear<br /> (or water_velocity_shear) || s-1 || [TIME, N_SHEAR_SENSORS]
|}
<math>^a</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
</div>

=Highly-recommended Level 1 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME <math>^a</math>
|-
| VIB<math>^b</math> || platform_vibration || NA || [TIME, N_VIB_SENSORS]
|-
| PRES<math>^c</math> || sea_water_pressure<br /> (water_pressure) || dbar || TIME <math>^a</math>
|-
| TEMP || sea_water_temperature<br /> (water_temperature) || degree_Celsius || [TIME <math>^a</math>, N_T_SENSORS]
|}
<math>^a</math> or TIME_SLOW or TIME_CTD
<br><math>^b</math> or ACC (see Table for optional variables)
<br><math>^c</math> for profiling instruments
</div>

=Optional Level 1 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| ACC || platform_acceleration || m s-2 || [TIME <math>^b</math>, N_ACC_SENSORS]
|-
| CNDC || sea_water_electrical_conductivity<br /> (water_electrical_conductivity) || S m-1 || [TIME_CTD <math>^b</math>, N_C_SENSORS]
|-
| GRADT || derivative_of_seawater_temperature_wrt_z <math>^c</math>|| degree_Celcius m-1 || [TIME, N_GRADT_SENSORS]
|-
| GRADC || derivative_of_seawater_conductivity_wrt_z <math>^c</math> || Typically not calibrated|| [TIME, N_GRADC_SENSORS]
|-
| PITCH || platform_pitch_angle || degree || TIME <math>^a</math>
|-
| ROLL || platform_roll_angle || degree || TIME <math>^a</math>
|}
<math>^a</math> or TIME_SLOW or TIME_CTD
<br><math>^b</math> or TIME_SLOW
<br><math>^c</math> or wrt_x or wrt_s; spatial derivative. Typically derived from the rate of change of temperature and divided by the profiling speed.
</div>

------
return to [[Dataset requirements for shear probes]] <br>
go to next: [[Level 2 data (shear probes)| Level 2 data]].

[[Category: Shear probes]]

Netcdf meta data (shear probes)

2024-01-12T12:34:37Z

Ilker:

<br>
Below we list the metadata '''required''' in a NetCDF data file, as well as the optional meta data we '''highly recommend''' that are included with the data set.

The parameter names should be used as listed (attention to underscores). The descriptions are example text or several options that are available for that parameter.

=Required Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
|title || E.g., Vertical micostructure profiler data from cruise XXX
|-
|authors || Names of authors
|-
|summary || An abstract describing the dataset
|-
|comment|| Supplementary technical details about the collecting and processing of the dataset
|-
|platform_type || The platform from which the data are collected. From the SeaVoX Platform Categories (L06) list,
e.g. sub-surface mooring, research vessel, sub-surface glider
|-
|source || The instrument used for collecting the data. For example, vertical microstructure profiler, VMP2000 SN009.
|-
|date_created || The date on which the data was created, yyyy-mm-ddTHH:MM:SSZ
|-
|date_update || The date on which the data was last modified, yyyy-mm-ddTHH:MM:SSZ
|-
|time_reference_year || Year for time reference
|-
|time_coverage_start || Time of the first data point in the dataset, yyyy-mm-ddTHH:MM:SSZ
|-
|time_coverage_end || Time of thelast data point in the dataset, yyyy-mm-ddTHH:MM:SSZ
|-
|geospatial_lat_min || Southern bound of data, decimal degrees, negative for South
|-
|geospatial_lat_max || Northern bound of data, decimal degrees, negative for South
|-
|geospatial_lon_min || Western bound of data, decimal degrees, negative for West
|-
|geospatial_lon_max || Eastern bound of data, decimal degrees, negative for West
|-
| fs_fast || Sampling frequency for fast (turbulence) channels
|-
| fs_slow <math>^a</math> || Sampling frequency for slow channels (if exist)
|-
| profiling_direction || E.g., horizontal, vertical, or glide
|-
| fft_length || Length of the Fast Fourier transform segments (in data points; note, fft_lengths_sec in seconds is optional)
|-
| diss_length || Length of data (in data points) used for each dissipation estimate
|-
| overlap || Length of overlap (in data points) in diss_length
|-
| goodman || Vibration coherent noise removal using the Goodman algorithm. 0=not applied; 1=applied
|-
| HP_cut || The high-pass filter cutoff frequency in Hz. Can be zero for no filtering.
|-
| conventions || A comma-separated list of the conventions that are followed by the dataset. e.g., CF-1.6, ACDD-1.3, ATOMIX
|-
| history || Provides an audit trail for modifications to the original data; e.g., Version 1
|-
| data_mode || D (D)elayed
|}
<math>^a</math> or fs_ctd or similar if such records are included
</div>

=Optional Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
| fft_length_sec || seconds
|-
| diss_length_sec || seconds
|-
| overlap_sec || (for diss_length_sec) seconds
|-
| f_AA || Hz, the anti-aliasing frequency.
|-
| FOM_limit || non-dimensional, if absent the FOM QC-flag is not set. Typically, 1.15.
|-
| diss_ratio_limit || non-dimensional, if absent the dissipation ration QC-flag is not set. Typically, 2.77.
|-
| despike_shear_fraction_limit || non-dimensional, if absent the de-spike fraction QC-flag is not set. Typically, 0.05.
|-
| despike_shear_iterations_limit || non-dimensional, if absent the de-spike iteration passes QC-flag is not set. Typically 8.
|-
| variance_resolved_limit || threshold for the minimum percent of variance resolved in a shear spectrum. Typically 50%.
|-
| spectral_model || e.g., Nasmyth, Lueck or Panchev-Kesich
|-
| spectrum_std || statistical uncertainty (standard deviation) of the natural logarithm of spectrum of shear
|-
| num_vibration_goodman || number of vibration or acceleration time series used to clean the shear spectrum
|-
| f_limit || upper limit to exclude frequencies that have contaminations. Typically infinity.
|-
| fit_2_isr || dissipation threshold to use the method of fitting to the inertial subrange. Typically 10-5 W/kg.
|-
|eps_remove_top_meters || if applicable, upper meters removed from dissipation estimates (e.g., because of ship)
|-
|area || e.g., Arctic Ocean, Barents Sea
|-
|geospatial_vertical_min|| 0
|-
|geospatial_vertical_max|| in m
|-
|geospatial_vertical_positive|| down, up
|-
|institution || e.g. University of Bergen
|-
|principal_investigator || Name of Principal Investigator
|-
|contact || email address of corresponding author (usually principal investigator)
|-
|project_name || name of project for which the data was collected
|-
|cruise || name of cruise from which the data was collected
|-
|vessel || name of vessel from which the data was collected
|-
|source || From the SeaVoX Platform Categories vocabulary (L06) list, e.g. “subsurface mooring”, ”ship”, ""sub-surface gliders"", ""autonomous underwater vehicle"" (CF)
|-
|references || key references
|-
|keywords || relevant keywords describing data e.g. shear probes
|-
|creator_name || name of person who generated the file
|-
|creator_email || email address of person who generated the file
|-
|creator_url || website address of the creator
|-
|acknowledgement|| acknowledgements for this data. e.g. this could include crew of ship or funders
|-
|station_name || name of station
|}

</div>

return to [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Shear probes

2023-11-25T16:34:08Z

Ilker:

== Welcome to the shear probe group! ==

The shear probe group addresses best practices in obtaining dissipation rate estimates from shear probes using a platform-independent approach. Our recommendations are applicable for measurements from probes attached to e.g., conventional gravity-driven loose-tether vertical profilers, ocean gliders, autonomous underwater vehicles (AUVs), or autonomous self-propelled floats (e.g. SOLO).

We submitted a manuscript "Best practices recommendations for estimating dissipation rates from shear probes" [https://www.dropbox.com/scl/fi/8983bwsyfd2hiu1qzxuua/Lueck_etal_ATOMIX_shear_probes_submitted.pdf?rlkey=6btifothhtqdhcsx4b84fmhw3&dl=0 Lueck et al.] to Frontiers in Marine Science.

== Scope ==

The shear probe group provides the following:

{|class="wikitable" style="margin-left: auto; margin-right: auto; border: none; text-align:center;"
|[[File:Flowchart symbol.png|180px|link=Flow chart for shear probes|Flow chart for shear probes]]
|[[File:M Rider Glider 1.JPG|250px|link=Dataset requirements for shear probes|Dataset requirements for shear probes]]
|[[File:MSS ADCP CTD (Schaffer).JPG|250px|link=Tentative benchmarks for shear probes|Benchmark datasets for shear probes]]
|-
|[[Flow chart for shear probes|Flow chart for <br>data processing]]
|[[Dataset requirements for shear probes | Dataset requirements <br>and format description]]
|[[Benchmark datasets for shear probes | Benchmark <br>datasets]]
|}

[[Category: Shear probes]]

-----
Return [[Main Page]]

Shear probes

2023-11-25T16:32:52Z

Ilker:

== Welcome to the shear probe group! ==

The shear probe group addresses best practices in obtaining dissipation rate estimates from shear probes using a platform-independent approach. Our recommendations are applicable for measurements from probes attached to e.g., conventional gravity-driven loose-tether vertical profilers, ocean gliders, autonomous underwater vehicles (AUVs), or autonomous self-propelled floats (e.g. SOLO).

We submitted a manuscript "Best practices recommendations for estimating dissipation rates from shear probes" [ https://www.dropbox.com/scl/fi/8983bwsyfd2hiu1qzxuua/Lueck_etal_ATOMIX_shear_probes_submitted.pdf?rlkey=6btifothhtqdhcsx4b84fmhw3&dl=0 Lueck et al.] to Frontiers in Marine Science.

== Scope ==

The shear probe group provides the following:

{|class="wikitable" style="margin-left: auto; margin-right: auto; border: none; text-align:center;"
|[[File:Flowchart symbol.png|180px|link=Flow chart for shear probes|Flow chart for shear probes]]
|[[File:M Rider Glider 1.JPG|250px|link=Dataset requirements for shear probes|Dataset requirements for shear probes]]
|[[File:MSS ADCP CTD (Schaffer).JPG|250px|link=Tentative benchmarks for shear probes|Benchmark datasets for shear probes]]
|-
|[[Flow chart for shear probes|Flow chart for <br>data processing]]
|[[Dataset requirements for shear probes | Dataset requirements <br>and format description]]
|[[Benchmark datasets for shear probes | Benchmark <br>datasets]]
|}

[[Category: Shear probes]]

-----
Return [[Main Page]]

Shear probes

2023-11-25T16:29:19Z

Ilker:

== Welcome to the shear probe group! ==

The shear probe group addresses best practices in obtaining dissipation rate estimates from shear probes using a platform-independent approach. Our recommendations are applicable for measurements from probes attached to e.g., conventional gravity-driven loose-tether vertical profilers, ocean gliders, autonomous underwater vehicles (AUVs), or autonomous self-propelled floats (e.g. SOLO).

We submitted a manuscript "Best practices recommendations for estimating dissipation rates from shear probes" [[Media:]] to Frontiers in Marine Science.

== Scope ==

The shear probe group provides the following:

{|class="wikitable" style="margin-left: auto; margin-right: auto; border: none; text-align:center;"
|[[File:Flowchart symbol.png|180px|link=Flow chart for shear probes|Flow chart for shear probes]]
|[[File:M Rider Glider 1.JPG|250px|link=Dataset requirements for shear probes|Dataset requirements for shear probes]]
|[[File:MSS ADCP CTD (Schaffer).JPG|250px|link=Tentative benchmarks for shear probes|Benchmark datasets for shear probes]]
|-
|[[Flow chart for shear probes|Flow chart for <br>data processing]]
|[[Dataset requirements for shear probes | Dataset requirements <br>and format description]]
|[[Benchmark datasets for shear probes | Benchmark <br>datasets]]
|}

[[Category: Shear probes]]

-----
Return [[Main Page]]

Benchmark datasets for shear probes

2023-11-22T20:15:30Z

Ilker:

These datasets can be accessed from a [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAgL55HqB50DQd2J11m7kl9a?dl=0|read-only dropbox folder], and will eventually be housed at the BODC center with a DOI.

We provide a number of matlab routines to read in and compare data from grouped NetCDF files that follow our recommended structure on our [https://github.com/SCOR-ATOMIX/shear-probes GitHub repository]. The Matlab function ATOMIX_load.m there can be used to load a benchmark data file..

{| class="wikitable sortable"
|-
! Filename Prefix
! Platform
! Instrument
! Region
! PI (ATOMIX)
! Comment
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAajUI9HIodADTYRJSfYb3ba/VMP250_TidalChannel/VMP250_TidalChannel_024.nc?dl=0 VMP250_TidalChannel_024]
| Ship
| VMP-250
| Haro Strait
| Lueck
| Intense turbulence. Large up/down drafts. Most estimates require fitting to the inertial subrange.
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAD3PcHlwHjyrMAA7er6jRG_a/EPSIFISH_BLT_NORTHATL/epsifish_epsilometer_blt_north_atl.nc?dl=0 EPSILOMETER_RockallTrough]
| Ship
| Epsilometer
| Rockall Trough
| Le Boyer
| Strong turbulence in a canyon
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AABKhtIRZSuuZSfwTJ3xNNaNa/VMP2000_FaroeBankChannel/VMP2000_FaroeBankChannel.nc?dl=0 VMP2000_FaroeBankChannel]
| Ship
| VMP-2000
| Faroe Bank Channel (North Atlantic)
| Fer
| Ranging from quiescent mid-water to turbulent, deep gravity current
|-
| [https://www.dropbox.com/scl/fi/f0y5ufcgzarecv35ha41p/MSS_Baltic.nc?dl=0 MSS_BalticSea]
| Ship
| MSS
| Baltic Sea
| Holtermann
|
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AADqZw8zwf93HpZMhF8MWAd-a/Nemo_MR1000_Minas_Passage/Nemo_MR1000_Minas_Passage_InStream.nc?dl=0 Nemo_MR1000_Minas_Passage_InStream]
| Mooring
| MicroRider
| Minas Passage (Bay of Fundy, NS)
| Lueck
| A swift tidal channel. All dissipation estimated from the inertial subrange
|-
|}

[[Category: Shear probes]]

-------------------------
return to [[Shear probes]] <br><br>
ATOMIX members: see also [[Tentative benchmarks for shear probes| tentative benchmarks for testers]]

Benchmark datasets for shear probes

2023-11-22T20:08:26Z

Ilker:

These datasets can be accessed from a [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAgL55HqB50DQd2J11m7kl9a?dl=0|read-only dropbox folder], and will eventually be housed at the BODC center with a DOI.

We provide a number of matlab routines to read in and compare data from grouped NetCDF files that follow our recommended structure on our [https://github.com/SCOR-ATOMIX/shear-probes GitHub repository]. The Matlab function ATOMIX_load.m there can be used to load a benchmark data file..

{| class="wikitable sortable"
|-
! Filename Prefix
! Platform
! Instrument
! Region
! PI (ATOMIX)
! Comment
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAajUI9HIodADTYRJSfYb3ba/VMP250_TidalChannel/VMP250_TidalChannel_024.nc?dl=0 VMP250_TidalChannel_024]
| Ship
| VMP-250
| Haro Strait
| Lueck
| Intense turbulence. Large up/down drafts. Most estimates require fitting to the inertial subrange.
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAD3PcHlwHjyrMAA7er6jRG_a/EPSIFISH_BLT_NORTHATL/epsifish_epsilometer_blt_north_atl.nc?dl=0 EPSILOMETER_RockallTrough]
| Ship
| Epsilometer
| Rockall Trough
| Le Boyer
| Strong turbulence in a canyon
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AABKhtIRZSuuZSfwTJ3xNNaNa/VMP2000_FaroeBankChannel/VMP2000_FaroeBankChannel.nc?dl=0 VMP2000_FaroeBankChannel]
| Ship
| VMP-2000
| Faroe Bank Channel (North Atlantic)
| Fer
| Ranging from quiescent mid-water to turbulent, deep gravity current
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAniGJlY-bwRplaiAV8AxC2a/MSS_BalticSea/MSS_Baltic.nc?dl=0 MSS_BalticSea]
| Ship
| MSS
| Baltic Sea
| Holtermann
|
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AADqZw8zwf93HpZMhF8MWAd-a/Nemo_MR1000_Minas_Passage/Nemo_MR1000_Minas_Passage_InStream.nc?dl=0 Nemo_MR1000_Minas_Passage_InStream]
| Mooring
| MicroRider
| Minas Passage (Bay of Fundy, NS)
| Lueck
| A swift tidal channel. All dissipation estimated from the inertial subrange
|-
|}

[[Category: Shear probes]]

-------------------------
return to [[Shear probes]] <br><br>
ATOMIX members: see also [[Tentative benchmarks for shear probes| tentative benchmarks for testers]]

Benchmark datasets for shear probes

2023-09-29T09:21:45Z

Ilker:

These datasets can be accessed from a [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAgL55HqB50DQd2J11m7kl9a?dl=0|read-only dropbox folder], and will eventually be housed at the BODC center with a DOI.

A Matlab function [[Media:ATOMIX_load.txt]] is provided to load a grouped NetCDF file prepared following the recommendations of the shear probe group. It can be used to load a benchmark data file. Remember to change the extension to "m".

{| class="wikitable sortable"
|-
! Filename Prefix
! Platform
! Instrument
! Region
! PI (ATOMIX)
! Comment
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAajUI9HIodADTYRJSfYb3ba/VMP250_TidalChannel/VMP250_TidalChannel_024.nc?dl=0 VMP250_TidalChannel_024]
| Ship
| VMP-250
| Haro Strait
| Lueck
| Intense turbulence. Large up/down drafts. Most estimates require fitting to the inertial subrange.
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAD3PcHlwHjyrMAA7er6jRG_a/EPSIFISH_BLT_NORTHATL/epsifish_epsilometer_blt_north_atl.nc?dl=0 EPSILOMETER_RockallTrough]
| Ship
| Epsilometer
| Rockall Trough
| Le Boyer
| Strong turbulence in a canyon
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AABKhtIRZSuuZSfwTJ3xNNaNa/VMP2000_FaroeBankChannel/VMP2000_FaroeBankChannel.nc?dl=0 VMP2000_FaroeBankChannel]
| Ship
| VMP-2000
| Faroe Bank Channel (North Atlantic)
| Fer
| ranging from quiescent mid-water to turbulent, deep gravity current
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAniGJlY-bwRplaiAV8AxC2a/MSS_BalticSea/MSS_Baltic_0330.nc?dl=0 MSS_BalticSea]
| Ship
| MSS
| Baltic Sea
| Holtermann
|
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AADqZw8zwf93HpZMhF8MWAd-a/Nemo_MR1000_Minas_Passage/Nemo_MR1000_Minas_Passage_InStream.nc?dl=0 Nemo_MR1000_Minas_Passage_InStream]
| Mooring
| MicroRider
| Minas Passage (Bay of Fundy, NS)
| Lueck
| a swift tidal channel. Dissipation estimated from the inertial subrange
|-
|}

[[Category: Shear probes]]

-------------------------
return to [[Shear probes]] <br><br>
ATOMIX members: see also [[Tentative benchmarks for shear probes| tentative benchmarks for testers]]

File:ATOMIX load.txt

2023-09-29T09:19:03Z

Ilker: A Matlab function to load a grouped NetCDF file prepared following the recommendations of the shear probe group. It can be used to load a benchmark data file. Remember to change the extension to "m".

== Summary ==
A Matlab function to load a grouped NetCDF file prepared following the recommendations of the shear probe group. It can be used to load a benchmark data file. Remember to change the extension to "m".

Level 4 data (shear probes)

2023-09-21T07:26:35Z

Ilker:

Level 4 data include the final dissipation estimates as time series, as well as indicators for the quality and accuracy of the estimates and additional derived parameters. It is saved in the NetCDF group "L4_dissipation". Each dissipation estimate in level 4 corresponds to a spectrum in the level 3 data. Consequently, the level 3 and 4 TIME dimensions are the same. Parameter EPSI_FINAL is the final dissipation rate estimate, averaged of the selected estimates (using the [[Quality_control_coding | QC flags]]) at that depth.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments
|-
|N_SHEAR_SENSORS ||number of shear channels (shear sensors)
|}
</div>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimensions
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^c</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section _of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA ||
|-
| EPSI || specific_turbulent_kinetic_energy_dissipation _in_water || W kg-1 || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_FINAL || specific_turbulent_kinetic_energy_dissipation _in_water || W kg-1 || TIME_SPECTRA
|-
| KMAX || maximum_wavenumber_used_for_estimating_ turbulent_kinetic_energy_dissipation || cpm || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| N_S || number_of_spectral_points_used_for_estimating_turbulent_kinetic_energy_dissipation || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_FLAGS <math>^a</math> || dissipation_qc_flags || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| METHOD <math>^b</math>|| method_used_for_estimating_ turbulent_kinetic_energy_dissipation || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|}
<math>^a</math> Quality control coding for the final dissipation estimate.

<math>^b</math> METHOD=0 for spectral integration, METHOD=1 for fitting to the inertial subrange.

<math>^c</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
</div>

=Optional Level 4 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| KVISC || kinematic_viscosity_of_water || m2 s-1 || TIME_SPECTRA
|-
| FOM || figure_of_merit || - || [TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| MAD || mean_absolute_deviation || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| VAR_RESOLVED || variance_resolved || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| KMIN || minimum_wavenumber_used_for_estimating_ turbulent_kinetic_energy_dissipation || cpm ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| EPSI_STD || expected_standard_deviation_of_the_ logarithm_of_the_dissipation_estimate || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| DESPIKE_FRACTION_SH || fraction_of_shear_data_modified_by_despiking_algorithm || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|-
| DESPIKE_PASS_COUNT_SH || number_of_despike_passes_for_shear_probes || - ||[TIME_SPECTRA, N_SHEAR_SENSORS]
|}

</div>

-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 3 data (shear probes)| Level 3 data]].
[[Category:Shear probes]]

Level 3 data (shear probes)

2023-09-21T07:22:18Z

Ilker:

Level 3 data contains the raw (and optionally cleaned) [[Spectrum|spectra]] derived from level 2 time series and is saved in the NetCDF group "L3_spectra". Level 3 parameters are defined along a new TIME [[Netcdf dimensions (shear probes)|dimension]], which is the average time of the individual spectral segments. The length of the TIME dimension equals the number of spectral segments. Parameter for the calculation of the spectra, e.g. segment length, are provided in the [[Netcdf meta data (shear probes)|meta data]].

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channels (shear sensors)
|-
| N_***_SENSORS || number of *** channels (such as ACC and VIB)
|-
| N_SH_ACC_SPEC || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^a</math> || dimension for 1 data point (for the entire analysis)
|}
</div>

<math>^a</math> This dimension is 1x1. Use, for example, for N_FFT_SEGMENTS (number_of_fft_segments), SPEC_STD (standard_deviation_uncertainty_of_shear_spectrum), and is one value for the entire analysis. <br>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^a</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA
|-
| SH_SPEC || shear_probe_spectrum || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|-
| KCYC || cyclic_wavenumber || cpm || [TIME_SPECTRA, N_WAVENUMBER]
|-
| SH_SPEC_CLEAN<math>^b</math>|| shear_probe_spectrum_clean || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|-
| N_FFT_SEGMENTS || number_of_fft_segments || - || N_GLOBAL_VALUES
|-
| N_VIB_SENSORS || number_of_vibration_sensors_used_for_cleaning_spectra || - || N_GLOBAL_VALUES
|-
| SPEC_STD || standard_deviation_uncertainty_of_shear_spectrum || - || N_GLOBAL_VALUES
|}
<math>^a</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"

<math>^b</math> SH_SPEC_CLEAN must be included in the file if these spectra were used to compute <math>\varepsilon</math>

</div>

=Optional Level 3 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| ACC_SPEC || acceleration_sensor_spectrum || m2 s-4 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_ACCEL_SENSORS]
|-
| VIB_SPEC || vibration_sensor_spectrum || - || [TIME_SPECTRA, WAVENUMBER, N_VIB_SENSORS]
|-
| SH_VIB_SPEC ||shear_and_vibration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_VIB_SPEC]
|-
| SH_ACC_SPEC ||shear_and_acceleration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC]
|-
| DOF || degrees_of_freedom_of_spectrum || - || N_GLOBAL_VALUES
|}
</div>

[[Category: Shear probes]]
-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 2 data (shear probes)| Level 2 data]]<br>
go to next: [[Level 4 data (shear probes)| Level 4 data]].

Level 3 data (shear probes)

2023-09-21T07:21:32Z

Ilker:

Level 3 data contains the raw (and optionally cleaned) [[Spectrum|spectra]] derived from level 2 time series and is saved in the NetCDF group "L3_spectra". Level 3 parameters are defined along a new TIME [[Netcdf dimensions (shear probes)|dimension]], which is the average time of the individual spectral segments. The length of the TIME dimension equals the number of spectral segments. Parameter for the calculation of the spectra, e.g. segment length, are provided in the [[Netcdf meta data (shear probes)|meta data]].

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channels (shear sensors)
|-
| N_***_SENSORS || number of *** channels (such as ACC and VIB)
|-
| N_SH_ACC_SPEC || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^a</math> || dimension for 1 data point (for the entire analysis)
|}
</div>

<math>^a</math> This dimension is 1x1. Use, for example, for N_FFT_SEGMENTS (number_of_fft_segments), SPEC_STD (standard_deviation_uncertainty_of_shear_spectrum), and is one value for the entire analysis. <br>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^a</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA
|-
| SH_SPEC || shear_probe_spectrum || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|-
| KCYC || cyclic_wavenumber || cpm || [TIME_SPECTRA, N_WAVENUMBER]
|-
| SH_SPEC_CLEAN<math>^b</math>|| shear_probe_spectrum_clean || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|-
| N_FFT_SEGMENTS || number_of_fft_segments || - || N_GLOBAL_VALUES
|-
| N_VIB_SENSORS || number_of_vibration_sensors_used_for_cleaning_spectra || - || N_GLOBAL_VALUES
|-
| SPEC_STD || standard_deviation_uncertainty_of_shear_spectrum || - || N_GLOBAL_VALUES
|}
<math>^a</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"

<math>^b</math> SH_SPEC_CLEAN must be included in the file if these spectra were used to compute <math>\varepsilon</math>

</div>

=Optional Level 3 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| ACC_SPEC || acceleration_sensor_spectrum || m2 s-4 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_ACCEL_SENSORS]
|-
| VIB_SPEC || vibration_sensor_spectrum || - || [TIME_SPECTRA, WAVENUMBER, N_VIB_SENSORS]
|-
| SH_VIB_SPEC ||shear_and_vibration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_VIB_SPEC]
|-
| SH_ACC_SPEC ||shear_and_acceleration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC]
|-
| DOF || degrees_of_freedom_of_spectrum || - || 1
|}
</div>

[[Category: Shear probes]]
-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 2 data (shear probes)| Level 2 data]]<br>
go to next: [[Level 4 data (shear probes)| Level 4 data]].

Level 3 data (shear probes)

2023-09-21T07:16:43Z

Ilker:

Level 3 data contains the raw (and optionally cleaned) [[Spectrum|spectra]] derived from level 2 time series and is saved in the NetCDF group "L3_spectra". Level 3 parameters are defined along a new TIME [[Netcdf dimensions (shear probes)|dimension]], which is the average time of the individual spectral segments. The length of the TIME dimension equals the number of spectral segments. Parameter for the calculation of the spectra, e.g. segment length, are provided in the [[Netcdf meta data (shear probes)|meta data]].

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channels (shear sensors)
|-
| N_***_SENSORS || number of *** channels (such as ACC and VIB)
|-
| N_SH_ACC_SPEC || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^a</math> || dimension for 1 data point (for the entire analysis)
|}
</div>

<math>^a</math> This dimension is 1x1. Use, for example, for N_FFT_SEGMENTS (number_of_fft_segments), SPEC_STD (standard_deviation_uncertainty_of_shear_spectrum), and is one value for the entire analysis. <br>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^b</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA
|-
| SH_SPEC || shear_probe_spectrum || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|-
| KCYC || cyclic_wavenumber || cpm || [TIME_SPECTRA, N_WAVENUMBER]
|-
| DOF || degrees_of_freedom_of_spectrum || - || 1
|-
| SH_SPEC_CLEAN<math>^a</math>|| shear_probe_spectrum_clean || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|}
<math>^a</math> SH_SPEC_CLEAN must be included in the file if these spectra were used to compute <math>\varepsilon</math>

<math>^b</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
</div>

=Optional Level 3 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| ACC_SPEC || acceleration_sensor_spectrum || m2 s-4 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_ACCEL_SENSORS]
|-
| VIB_SPEC || vibration_sensor_spectrum || - || [TIME_SPECTRA, WAVENUMBER, N_VIB_SENSORS]
|-
| SH_VIB_SPEC ||shear_and_vibration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_VIB_SPEC]
|-
| SH_ACC_SPEC ||shear_and_acceleration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC]
|}
</div>

[[Category: Shear probes]]
-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 2 data (shear probes)| Level 2 data]]<br>
go to next: [[Level 4 data (shear probes)| Level 4 data]].

Netcdf dimensions (shear probes)

2023-09-21T07:14:58Z

Ilker:

== Netcdf dimensions (shear probes) ==
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable"
|-
! Dimension Name !! Description
|-
| TIME || The length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different than fast)
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channel (shear sensors)
|-
| N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
| N_SH_ACC_SPEC <math>^c</math> || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC <math>^d</math> || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^e</math> || dimension for 1 data point (for the entire analysis)
|}
<math>^a</math> Typically we assume TIME for the fast-sampled microstructure channels, and eventually _SLOW or _CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br><br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors <br>
N_GRADT_SENSORS for thermistors <br>
N_GRADC_SENSORS for microconductivity sensors <br>
<br>
<math>^c</math> number of shear sensors x number of ACC sensors <br>
<br>
<math>^d</math> number of shear sensors x number of VIB sensors <br>

<math>^e</math> This dimension is 1x1. Use, for example, for N_FFT_SEGMENTS (number_of_fft_segments), SPEC_STD (standard_deviation_uncertainty_of_shear_spectrum), and is one value for the entire analysis. <br>

</div>
<br>
Go to: [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Netcdf dimensions (shear probes)

2023-09-21T07:14:27Z

Ilker:

== Netcdf dimensions (shear probes) ==
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable"
|-
! Dimension Name !! Description
|-
| TIME || The length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different than fast)
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channel (shear sensors)
|-
| N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
| N_SH_ACC_SPEC <math>^c</math> || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC <math>^d</math> || number of shear-vibration cross spectra
|-
| N_GLOBAL_VALUES <math>^e</math> || dimension for 1 data point (for the entire analysis)
|}
<math>^a</math> Typically we assume TIME for the fast-sampled microstructure channels, and eventually _SLOW or _CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br><br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors <br>
N_GRADT_SENSORS for thermistors <br>
N_GRADC_SENSORS for microconductivity sensors <br>
<br>
<math>^c</math> number of shear sensors x number of ACC sensors <br>
<br>
<math>^d</math> number of shear sensors x number of VIB sensors <br>
<e>
<math>^d</math> This dimension is 1x1. Use, for example, for N_FFT_SEGMENTS (number_of_fft_segments), SPEC_STD (standard_deviation_uncertainty_of_shear_spectrum), and is one value for the entire analysis. <br>

</div>
<br>
Go to: [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Level 1 data (shear probes)

2023-09-21T07:07:21Z

Ilker: /* Optional Level 1 Variables */

Level 1 data refers to the full resolution data in physical units, e.g. the regularly sampled time series of [[Convert the shear probe data|converted shear probe data]]. If needed, a transfer function for shear is given. Below, a table with parameters included in the level 1 data set is compiled. The parameter names and definitions fit the [[NetCDF parameter]] attributes and data is stored as a NetCDF group with the name "L1_converted".

In the standard names, "sea_water" can be replaced with "water" if working in freshwater environments. This is specified in some entries below but not all.

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension short name !! description
|-
| TIME || length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from the *** sensor (e.g., CTD or SLOW)
|-
|N_SHEAR_SENSORS ||number of shear channel (shear sensors)
|-
|N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
|}
<math>^a</math> Typically we assume TIME for the fast-sampled microstructure channels, and for example, _SLOW or _CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors, <br>
N_ACC_SENSORS for vibration acceleration sensors, <br>
N_GRADT_SENSORS for thermistors, <br>
N_GRADC_SENSORS for microconductivity sensors. <br>
</div>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^a</math> || TIME
|-
| SHEAR || sea_water_velocity_shear<br /> (or water_velocity_shear) || s-1 || [TIME, N_SHEAR_SENSORS]
|}
<math>^a</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
</div>

=Highly-recommended Level 1 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME <math>^a</math>
|-
| VIB<math>^b</math> || platform_vibration || NA || [TIME, N_VIB_SENSORS]
|-
| PRES<math>^c</math> || sea_water_pressure<br /> (water_pressure) || dbar || TIME <math>^a</math>
|-
| TEMP || sea_water_temperature<br /> (water_temperature) || degree_Celsius || [TIME <math>^a</math>, N_T_SENSORS]
|}
<math>^a</math> or TIME_SLOW or TIME_CTD
<br><math>^b</math> or ACC (see Table for optional variables)
<br><math>^c</math> for profiling instruments
</div>

=Optional Level 1 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| VIB || platform_vibration || NA || [TIME, N_VIB_SENSORS]
|-
| ACC || platform_acceleration || m s-2 || [TIME <math>^b</math>, N_ACC_SENSORS]
|-
| CNDC || sea_water_electrical_conductivity<br /> (water_electrical_conductivity) || S m-1 || [TIME_CTD <math>^b</math>, N_C_SENSORS]
|-
| GRADT || derivative_of_seawater_temperature_wrt_z <math>^c</math>|| degree_Celcius m-1 || [TIME, N_GRADT_SENSORS]
|-
| GRADC || derivative_of_seawater_conductivity_wrt_z <math>^c</math> || Typically not calibrated|| [TIME, N_GRADC_SENSORS]
|-
| PITCH || platform_pitch_angle || degree || TIME <math>^a</math>
|-
| ROLL || platform_roll_angle || degree || TIME <math>^a</math>
|}
<math>^a</math> or TIME_SLOW or TIME_CTD
<br><math>^b</math> or TIME_SLOW
<br><math>^c</math> or wrt_x or wrt_s; spatial derivative. Typically derived from the rate of change of temperature and divided by the profiling speed.
</div>

------
return to [[Dataset requirements for shear probes]] <br>
go to next: [[Level 2 data (shear probes)| Level 2 data]].

[[Category: Shear probes]]

Netcdf meta data (shear probes)

2023-09-21T07:03:11Z

Ilker:

<br>
Below we list the metadata '''required''' in a NetCDF data file, as well as the optional meta data we '''highly recommend''' that are included with the data set.

The parameter names should be used as listed (attention to underscores). The descriptions are example text or several options that are available for that parameter.

=Required Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
|title || e.g., Vertical micostructure profiler data from cruise XXX
|-
|summary || required by ACDD
|-
|comment|| required by CF
|-
|platform_type ||research vessel, sub-surface glider etc
|-
|creation_time || yyyy-mm-ddTHH:MM:SSZ
|-
|date_created || yyyy-mm-ddTHH:MM:SSZ
|-
|date_update || yyyy-mm-ddTHH:MM:SSZ
|-
|time_reference_year || year for time reference
|-
| fs_fast || sampling frequency for fast channels
|-
| fs_slow <math>^a</math> || sampling frequency for slow channels
|-
| profiling_direction || horizontal, vertical, glide
|-
| fft_length || as data points (note, fft_lengths_sec in seconds is optional)
|-
| diss_length || as data points
|-
| overlap || (for diss_length) as data points
|-
| num_fft_segments || number of FFT segments
|-
| goodman || 0=not applied; 1=applied
|-
| HP_cut || the high-pass filter cutoff frequency in Hz. Can be zero for no filtering.
|-
| conventions || CF-1.6, ACDD-1.3, ATOMIX
|-
| history || Version 1
|-
| data_mode || D #(D)elayed
|}
<math>^a</math> or fast_ctd or similar if such records are included
</div>

=Optional Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
| fft_length_sec || seconds
|-
| diss_length_sec || seconds
|-
| overlap_sec || (for diss_length_sec) seconds
|-
| f_AA || Hz, the anti-aliasing frequency.
|-
| FOM_limit || non-dimensional, if absent the FOM QC-flag is not set. Typically, 1.15.
|-
| diss_ratio_limit || non-dimensional, if absent the dissipation ration QC-flag is not set. Typically, 2.77.
|-
| despike_shear_fraction_limit || non-dimensional, if absent the de-spike fraction QC-flag is not set. Typically, 0.05.
|-
| despike_shear_iterations_limit || non-dimensional, if absent the de-spike iteration passes QC-flag is not set. Typically 8.
|-
| variance_resolved_limit || threshold for the minimum percent of variance resolved in a shear spectrum. Typically 50%.
|-
| spectral_model || e.g., Nasmyth, Lueck or Panchev-Kesich
|-
| spectrum_std || statistical uncertainty (standard deviation) of the natural logarithm of spectrum of shear
|-
| num_vibration_goodman || number of vibration or acceleration time series used to clean the shear spectrum
|-
| f_limit || upper limit to exclude frequencies that have contaminations. Typically infinity.
|-
| fit_2_isr || dissipation threshold to use the method of fitting to the inertial subrange. Typically 10-5 W/kg.
|-
|eps_remove_top_meters || if applicable, upper meters removed from dissipation estimates (e.g., because of ship)
|-
|area || e.g., Arctic Ocean, Barents Sea
|-
|geospatial_lat_min || latitude minimum of data
|-
|geospatial_lat_max || latitude maximum of data
|-
|geospatial_lon_min || longitude minimum of data
|-
|geospatial_lon_max || longitude maximum of data
|-
|geospatial_vertical_min|| 0
|-
|geospatial_vertical_max|| in m
|-
|geospatial_vertical_positive|| down, up
|-
|time_coverage_start || yyyy-mm-ddTHH:MM:SSZ
|-
|time_coverage_end || yyyy-mm-ddTHH:MM:SSZ
|-
|institution || e.g. University of Bergen
|-
|principal_investigator || Name of Principal Investigator
|-
|authors || Names of authors
|-
|contact || email address of corresponding author (usually principal investigator)
|-
|project_name || name of project for which the data was collected
|-
|cruise || name of cruise from which the data was collected
|-
|vessel || name of vessel from which the data was collected
|-
|source || From the SeaVoX Platform Categories vocabulary (L06) list, e.g. “subsurface mooring”, ”ship”, ""sub-surface gliders"", ""autonomous underwater vehicle"" (CF)
|-
|references || key references
|-
|keywords || relevant keywords describing data e.g. shear probes
|-
|creator_name || name of person who generated the file
|-
|creator_email || email address of person who generated the file
|-
|creator_url || website address of the creator
|-
|acknowledgement|| acknowledgements for this data. e.g. this could include crew of ship or funders
|-
|station_name || name of station
|}

</div>

return to [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Netcdf dimensions (shear probes)

2023-09-20T19:05:37Z

Ilker:

== Netcdf dimensions (shear probes) ==
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable"
|-
! Dimension Name !! Description
|-
| TIME || The length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different than fast)
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channel (shear sensors)
|-
| N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
| N_SH_ACC_SPEC <math>^c</math> || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC <math>^d</math> || number of shear-vibration cross spectra
|}
<math>^a</math> Typically we assume TIME for the fast-sampled microstructure channels, and eventually _SLOW or _CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br><br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors <br>
N_GRADT_SENSORS for thermistors <br>
N_GRADC_SENSORS for microconductivity sensors <br>
<br>
<math>^c</math> number of shear sensors x number of ACC sensors <br>
<br>
<math>^d</math> number of shear sensors x number of VIB sensors <br>

</div>
<br>
Go to: [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Netcdf dimensions (shear probes)

2023-09-20T09:07:52Z

Ilker:

== Netcdf dimensions (shear probes) ==
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable"
|-
! Dimension Name !! Description
|-
| TIME || The length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different than fast)
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_SECTIONS || number of sections
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channel (shear sensors)
|-
| N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
| N_SH_ACC_SPEC <math>^c</math> || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC <math>^d</math> || number of shear-vibration cross spectra
|}
<math>^a</math> Typically we assume TIME for the fast-sampled microstructure channels, and eventually _SLOW or _CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br><br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors <br>
N_GRADT_SENSORS for thermistors <br>
N_GRADC_SENSORS for microconductivity sensors <br>
<br>
<math>^c</math> number of shear sensors x number of ACC sensors <br>
<br>
<math>^d</math> number of shear sensors x number of VIB sensors <br>

</div>
<br>
Go to: [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Level 3 data (shear probes)

2023-09-20T08:59:16Z

Ilker:

Level 3 data contains the raw (and optionally cleaned) [[Spectrum|spectra]] derived from level 2 time series and is saved in the NetCDF group "L3_spectra". Level 3 parameters are defined along a new TIME [[Netcdf dimensions (shear probes)|dimension]], which is the average time of the individual spectral segments. The length of the TIME dimension equals the number of spectral segments. Parameter for the calculation of the spectra, e.g. segment length, are provided in the [[Netcdf meta data (shear probes)|meta data]].

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channels (shear sensors)
|-
| N_***_SENSORS || number of *** channels (such as ACC and VIB)
|-
| N_SH_ACC_SPEC || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC || number of shear-vibration cross spectra
|}
</div>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^b</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA
|-
| SH_SPEC || shear_probe_spectrum || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|-
| KCYC || cyclic_wavenumber || cpm || [TIME_SPECTRA, N_WAVENUMBER]
|-
| DOF || degrees_of_freedom_of_spectrum || - || 1
|-
| SH_SPEC_CLEAN<math>^a</math>|| shear_probe_spectrum_clean || s-2 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_SHEAR_SENSORS]
|}
<math>^a</math> SH_SPEC_CLEAN must be included in the file if these spectra were used to compute <math>\varepsilon</math>

<math>^b</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
</div>

=Optional Level 3 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| ACC_SPEC || acceleration_sensor_spectrum || m2 s-4 cpm-1 || [TIME_SPECTRA, N_WAVENUMBER, N_ACCEL_SENSORS]
|-
| VIB_SPEC || vibration_sensor_spectrum || - || [TIME_SPECTRA, WAVENUMBER, N_VIB_SENSORS]
|-
| SH_VIB_SPEC ||shear_and_vibration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_VIB_SPEC]
|-
| SH_ACC_SPEC ||shear_and_acceleration_cross-spectral_matrix || - || [TIME_SPECTRA, N_WAVENUMBER, N_SH_ACC_SPEC]
|}
</div>

[[Category: Shear probes]]
-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 2 data (shear probes)| Level 2 data]]<br>
go to next: [[Level 4 data (shear probes)| Level 4 data]].

Netcdf dimensions (shear probes)

2023-09-20T08:57:44Z

Ilker:

== Netcdf dimensions (shear probes) ==
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable"
|-
! Dimension Name !! Description
|-
| TIME || The length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different than fast)
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| N_WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channel (shear sensors)
|-
| N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
| N_SH_ACC_SPEC <math>^c</math> || number of shear-acceleration cross spectra
|-
| N_SH_VIB_SPEC <math>^d</math> || number of shear-vibration cross spectra
|}
<math>^a</math> Typically we assume TIME for the fast-sampled microstructure channels, and eventually _SLOW or _CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br><br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors <br>
N_GRADT_SENSORS for thermistors <br>
N_GRADC_SENSORS for microconductivity sensors <br>
<br>
<math>^c</math> number of shear sensors x number of ACC sensors <br>
<br>
<math>^d</math> number of shear sensors x number of VIB sensors <br>

</div>
<br>
Go to: [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Figure of merit (FOM)

2023-09-15T13:31:51Z

Ilker: Created page with "{{DefineConcept |description=A measure of how closely the measured shear spectrum follows a model spectrum |article_type=Concepts }} The figure of merit, <math>\mathrm{FOM}</m..."

{{DefineConcept
|description=A measure of how closely the measured shear spectrum follows a model spectrum
|article_type=Concepts
}}
The figure of merit, <math>\mathrm{FOM}</math>, provides a measure of how closely the measured spectrum follows a model of the shear spectrum.
The measurement uncertainty of a shear spectrum appears to be distributed log-normally<ref name=“Lueck2022b”> Lueck, R. G., 2022b: The statistics of oceanic turbulence measurements. Part 2: Shear spectra and a new spectral model. J. Atmos. Oceanic Technol., –, in press, doi:--.</ref> with a variance equal to

<math>\sigma^2_{\ln\Psi}=\frac{5}{4} \left( N_f - N_V \right)^{-7/9}</math>

where <math>N_f</math> is the number of fft-segments used to make the spectral estimate, with 50% overlap and a cosine window, and <math>N_V</math> is the number of vibration and other signals that were used to clean the spectrum of shear using the Goodman<ref name=“Goodmanetal2006”> Goodman L., Levine E.R. and Lueck, R. G., 2006: On measuring the terms of the turbulent kinetic energy budget from an AUV. J. Atmos. Oceanic Technol., '''23''', 977-990, doi:10.1175/JTECH1889.1</ref> coherent noise removal algorithm.

The spectral values used to estimate the variance of shear (and, hence, the rate of dissipation) should be compared to a reference spectrum of shear for the estimated rate of dissipation.
Because the standard deviation of a spectrum, <math>\sigma_{\ln\Psi}</math> is fairly large, the choice of a reference spectrum is not crucial for most practical values of <math>N_f</math>.
The choices for a reference spectrum include the Panchev-Kesich spectrum
<ref name=“Rogetetal”> Roget E., Lozovatsky I., Sanchez-Martin X., and Figueroa M., 2006: Microstructure measurements in natural waters: Methodology and applications. Progress in Oceanography, '''70''', 126-148, doi:10.1016/j.pocean.2006.07.003</ref>,
or the Nasmyth spectrum
<ref name=“Oakey1982”> Oakey, N., 1982: Determination of the Rate of Dissipation of Turbulent Kinetic Energy from Simultaneous Temperature and Velocity Shear Microstructure Measurements. J. Phys. Oceanogr., '''12''', 256-271, doi:10.1175/1520-0485(1982)012</ref>,
or a universal spectrum based on over 14000 dimensional spectra <ref name=“Lueck2022b”/>,

The chosen reference spectrum must be dimensionalised using the estimated rate of dissipation.
The difference of the logarithm of the measured spectrum and the logarithm of the reference spectrum, for the wavenumber range used to estimated the rate of dissipation, is expected to be distributed normally with a standard deviation of <math>\sigma_{\ln\Psi}</math>.
However, the sample standard deviation (of the differences) uses a finite number of samples (spectral values) and will inevitably differ from the expectation.

If one draws <math>N_s</math> samples from a population that has a standard deviation of 1, then for 97.5% of the draws the samples will have a standard deviation smaller than

<math> T_S = 1 + \sqrt{\frac{2}{N_s}} </math>

and they will have a mean absolute deviation (MAD) smaller than

<math> T_M = 0.8 + \sqrt{\frac{1,56}{N_s}} </math>.

Thus, a measure of the quality of a spectrum is

<math> F_S = \frac{s_{\ln\Psi}}{\sigma_{\ln\Psi}} \, \frac{1}{T_S} </math>

where <math>s_{\ln\Psi}</math> is the sample standard deviation.
Or, if based on the mean absolute deviation, the quality metric is

<math> \mathrm{FOM} = \frac{\mathrm{MAD}_{\ln\Psi}}{\sigma_{\ln\Psi}} \, \frac{1}{T_M} </math>

where <math>\mathrm{MAD}_{\ln\Psi}</math> is the sample mean absolute deviation.
Thus, the expectation is that <math>\mathrm{FOM}</math> and <math>F_S</math> will be smaller than 1 for 97.5% of the spectra if the measurement quality is good.
Values significantly larger than 1 should be flagged, and not used for dissipation estimation.
We recommend using <math>\mathrm{FOM}</math> and denote it as the figure of merit.

The various spectral models differ by about 15% and, therefore, an appropriate recommended cutoff for rejection is <math>\mathrm{FOM}</math> = 1.15, and good practice requires that the threshold be explicitly identified for an estimate of the rate of dissipation.

==References==
<references />

-----------------------------
return to [[Flow chart for shear probes]]

[[Category:Shear probes]]

Level 3 data (shear probes)

2023-09-15T12:53:01Z

Ilker:

Level 3 data contains the raw (and optionally cleaned) [[Spectrum|spectra]] derived from level 2 time series and is saved in the NetCDF group "L3_spectra". Level 3 parameters are defined along a new TIME [[Netcdf dimensions (shear probes)|dimension]], which is the average time of the individual spectral segments. The length of the TIME dimension equals the number of spectral segments. Parameter for the calculation of the spectra, e.g. segment length, are provided in the [[Netcdf meta data (shear probes)|meta data]].

=Dimensions=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable sortable"
! Dimension name !! description
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| WAVENUMBER || length of the wavenumber array
|-
|N_SHEAR_SENSORS || number of shear channels (shear sensors)
|-
|N_***_SENSORS || number of *** channels (such as ACC and VIB)
|-
| SH_ACC_SPEC || number of shear-acceleration cross spectra
|-
| SH_VIB_SPEC || number of shear-vibration cross spectra
|}
</div>

=Required Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| TIME || time || [http://cfconventions.org/cf-conventions/cf-conventions#time-coordinate CF-Conventions compatible offset]<math>^b</math> || TIME_SPECTRA
|-
| SECTION_NUMBER || unique_identifier_for_each_section_ of_data_from_timeseries || - || TIME_SPECTRA
|-
| PSPD_REL || platform_speed_wrt_sea_water || m s-1 || TIME_SPECTRA
|-
| SH_SPEC || shear_probe_spectrum || s-2 cpm-1 || [TIME_SPECTRA, WAVENUMBER, N_SHEAR_SENSORS]
|-
| KCYC || cyclic_wavenumber || cpm || [TIME_SPECTRA, WAVENUMBER]
|-
| DOF || degrees_of_freedom_of_spectrum || - || 1
|-
| SH_SPEC_CLEAN<math>^a</math>|| shear_probe_spectrum_clean || s-2 cpm-1 || [TIME_SPECTRA, WAVENUMBER, N_SHEAR_SENSORS]
|}
<math>^a</math> SH_SPEC_CLEAN must be included in the file if these spectra were used to compute <math>\varepsilon</math>

<math>^b</math> i.e. "Days since YYYY-MM-DDT00:00:00Z"
</div>

=Optional Level 3 Variables=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Standard Name !! Units of measurement !! dimension
|-
| PRES || water_pressure || dbar || TIME_SPECTRA
|-
| ACC_SPEC || acceleration_sensor_spectrum || m2 s-4 cpm-1 || [TIME_SPECTRA, WAVENUMBER, N_ACCEL_SENSORS]
|-
| VIB_SPEC || vibration_sensor_spectrum || - || [TIME_SPECTRA, WAVENUMBER, N_VIB_SENSORS]
|-
| SH_VIB_SPEC ||shear_and_vibration_cross-spectral_matrix || - || [TIME_SPECTRA, WAVENUMBER, SH_VIB_SPEC]
|-
| SH_ACC_SPEC ||shear_and_acceleration_cross-spectral_matrix || - || [TIME_SPECTRA, WAVENUMBER, SH_ACC_SPEC]
|}
</div>

[[Category: Shear probes]]
-----
Return [[Dataset requirements for shear probes]]<br>
go to previous: [[Level 2 data (shear probes)| Level 2 data]]<br>
go to next: [[Level 4 data (shear probes)| Level 4 data]].

Netcdf meta data (shear probes)

2023-09-15T12:42:32Z

Ilker:

<br>
Below we list the metadata '''required''' in a NetCDF data file, as well as the optional meta data we '''highly recommend''' that are included with the data set.

The parameter names should be used as listed (attention to underscores). The descriptions are example text or several options that are available for that parameter.

=Required Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
|title || e.g., Vertical micostructure profiler data from cruise XXX
|-
|summary || required by ACDD
|-
|comment|| required by CF
|-
|platform_type ||research vessel, sub-surface glider etc
|-
|creation_time || yyyy-mm-ddTHH:MM:SSZ
|-
|date_created || yyyy-mm-ddTHH:MM:SSZ
|-
|date_update || yyyy-mm-ddTHH:MM:SSZ
|-
|time_reference_year || year for time reference
|-
| fs_fast || sampling frequency for fast channels
|-
| fs_slow <math>^a</math> || sampling frequency for slow channels
|-
| profiling_direction || horizontal, vertical, glide
|-
| fft_length || as data points (note, fft_lengths_sec in seconds is optional)
|-
| diss_length || as data points
|-
| overlap || as data points
|-
| goodman || 0=not applied; 1=applied
|-
| HP_cut || the high-pass filter cutoff frequency in Hz. Can be zero for no filtering.
|-
| conventions || CF-1.6, ACDD-1.3, ATOMIX
|-
| history || Version 1
|-
| data_mode || D #(D)elayed
|}
<math>^a</math> or fast_ctd or similar if such records are included
</div>

=Optional Metadata=
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
{| class="wikitable sortable"
|-
! Parameter Name !! Description
|-
| fft_length_sec || seconds
|-
| diss_length_sec || seconds
|-
| overlap_sec || seconds
|-
| f_AA || Hz, the anti-aliasing frequency.
|-
| FOM_limit || non-dimensional, if absent the FOM QC-flag is not set. Typically, 1.15.
|-
| diss_ratio_limit || non-dimensional, if absent the dissipation ration QC-flag is not set. Typically, 2.77.
|-
| despike_shear_fraction_limit || non-dimensional, if absent the de-spike fraction QC-flag is not set. Typically, 0.05.
|-
| despike_shear_iterations_limit || non-dimensional, if absent the de-spike iteration passes QC-flag is not set. Typically 8.
|-
| variance_resolved_limit || threshold for the minimum percent of variance resolved in a shear spectrum. Typically 50%.
|-
| f_limit || upper limit to exclude frequencies that have contaminations. Typically infinity.
|-
| fit_2_isr || dissipation threshold to use the method of fitting to the inertial subrange. Typically 10-5 W/kg.
|-
|area || e.g., Arctic Ocean, Barents Sea
|-
|geospatial_lat_min || latitude minimum of data
|-
|geospatial_lat_max || latitude maximum of data
|-
|geospatial_lon_min || longitude minimum of data
|-
|geospatial_lon_max || longitude maximum of data
|-
|geospatial_vertical_min|| 0
|-
|geospatial_vertical_max|| in m
|-
|geospatial_vertical_positive|| down, up
|-
|time_coverage_start || yyyy-mm-ddTHH:MM:SSZ
|-
|time_coverage_end || yyyy-mm-ddTHH:MM:SSZ
|-
|institution || e.g. University of Bergen
|-
|principal_investigator || Name of Principal Investigator
|-
|authors || Names of authors
|-
|contact || email address of corresponding author (usually principal investigator)
|-
|project_name || name of project for which the data was collected
|-
|cruise || name of cruise from which the data was collected
|-
|vessel || name of vessel from which the data was collected
|-
|source || From the SeaVoX Platform Categories vocabulary (L06) list, e.g. “subsurface mooring”, ”ship”, ""sub-surface gliders"", ""autonomous underwater vehicle"" (CF)
|-
|references || key references
|-
|keywords || relevant keywords describing data e.g. shear probes
|-
|creator_name || name of person who generated the file
|-
|creator_email || email address of person who generated the file
|-
|creator_url || website address of the creator
|-
|acknowledgement|| acknowledgements for this data. e.g. this could include crew of ship or funders
|-
|station_name || name of station
|}

</div>

return to [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Netcdf dimensions (shear probes)

2023-09-15T12:23:23Z

Ilker:

== Netcdf dimensions (shear probes) ==
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable"
|-
! Dimension Name !! Description
|-
| TIME || The length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different than fast)
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channel (shear sensors)
|-
| N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
| SH_ACC_SPEC <math>^c</math> || number of shear-acceleration cross spectra
|-
| SH_VIB_SPEC <math>^d</math> || number of shear-vibration cross spectra
|}
<math>^a</math> Typically we assume TIME for the fast-sampled microstructure channels, and eventually _SLOW or _CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br><br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors <br>
N_GRADT_SENSORS for thermistors <br>
N_GRADC_SENSORS for microconductivity sensors <br>
<br>
<math>^c</math> number of shear sensors x number of ACC sensors <br>
<br>
<math>^d</math> number of shear sensors x number of VIB sensors <br>

</div>
<br>
Go to: [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Netcdf dimensions (shear probes)

2023-09-15T12:22:13Z

Ilker:

== Netcdf dimensions (shear probes) ==
<div class="mw-collapsible mw-expand" data-collapsetext="Collapse" data-expandtext="Expand">
<br>

{| class="wikitable"
|-
! Dimension Name !! Description
|-
| TIME || The length of the record from turbulence (fast) data channels
|-
| TIME_*** <math>^a</math> || length of the record from slow data channels (if different than fast)
|-
| TIME_SPECTRA || length of the record of average times of spectral segments. This also equals time of dissipation estimates.
|-
| WAVENUMBER || length of the wavenumber array
|-
| N_SHEAR_SENSORS || number of shear channel (shear sensors)
|-
| N_***_SENSORS <math>^b</math> ||number of *** channel (sensors)
|-
| SH_ACC_SPEC || number of shear-acceleration cross spectra <math>^c</math>
|-
| SH_VIB_SPEC || number of shear-vibration cross spectra <math>^d</math>
|}
<math>^a</math> Typically we assume TIME for the fast-sampled microstructure channels, and eventually _SLOW or _CTD for slower sampled channels such as CTD and tilt sensors. If the application requires different time stamps for different sensors, this can be utilized like TIME_PITCH, TIME_ACC etc.
<br>
<math>^b</math> Please use these examples for related sensors:<br>
N_VIB_SENSORS for vibration (piezo-acceleration) sensors <br>
N_ACC_SENSORS for vibration acceleration sensors <br>
N_GRADT_SENSORS for thermistors <br>
N_GRADC_SENSORS for microconductivity sensors <br>
<math>^c</math> number of shear sensors x number of ACC sensors <br>
<math>^d</math> number of shear sensors x number of VIB sensors <br>

</div>
<br>
Go to: [[Dataset requirements for shear probes]]

[[Category:Shear probes]]

Dataset requirements for shear probes

2023-09-09T15:59:28Z

Ilker: /* Shear probe measurements: Data Format */

This page provides an overview of the NetCDF format of benchmark dataset for instruments that measure microstructure shear using airfoil probes. The data format recommended is summarized in [[#Shear probe measurements: Data Format|Data Format]] below.
<br>
Please use the following naming convention for [[Netcdf dimensions (shear probes)|standard dimensions]] and include the necessary [[Netcdf meta data (shear probes)|meta data]].

* [[Netcdf meta data (shear probes)|list of meta data]]
* [[Netcdf dimensions (shear probes)|list of dimension names]]
* [[Quality_control_coding|quality control coding for dissipation estimates]]

ATOMIX provides several [[Tentative benchmarks for shear probes|benchmark data sets]] following these guidelines.

= Minimum and desirable data set =
<div class="mw-collapsible" id="dataset" data-collapsetext="Collapse" data-expandtext="Expand">

* The absolute minimum signals and information required to estimate the rate of dissipation of kinetic energy consists of:

:* a sampled shear-probe signal,
:* a means of determining the speed of flow past the shear probe, and
:* a means to estimate the temperature of the fluid so that you can determine its kinematic viscosity.

In addition, it is highly recommended to have a minimum one vibration sensor or accelerometer that can be used to check and eventually correct for platform vibrations. The sampling rate of the shear-probe signal should exceed significantly (by a factor of 2 to 4) the value of 150U, where
U is the speed of the flow past the shear-probe. This speed is often called the speed of profiling, even when the probe is fixed in space and the current causes fluid to flow past the shear probe. The value of 150 cpm equals the spatial resolution of the commonly used shear probe.

* The desirable data set

A far more desirable, but not absolutely necessary, set of data consists of the following.

:* Two or more shear probes for measurement redundancy.
:* Vibration sensors or accelerometers that are sensitive to the directions of sensitivity of the shear probes.
:* An accurate thermometer.
:* A pressure transducer.
:* A signal that can be used to estimate the speed of flow past the shear probe.
:* Pitch and roll sensors.

Most commonly available instruments carry two shear probes that are frequently oriented so that they measure orthogonal components of the shear and, thus, provide two independent estimates of the rate of dissipation that you should agree statistically.
</div>

= Shear probe measurements: Data Format =

Following the recommendations of the [[Flow chart for shear probes | flow chart]], ATOMIX defined four processing levels a user needs to follow to obtain a standardized estimation of epsilon. The different levels are stored as groups in the NetCDF file, the group names are in brackets:

# [[Level 1 data (shear probes)|Timeseries in physical units (L1_converted)]]
#* full resolution data in physical units
# [[Level 2 data (shear probes)|Quality-controlled and segmented timeseries (L2_cleaned)]]
#* full resolution cleaned and despiked parameters from level 1, subdivided in individual [[Section|sections]].
# [[Level 3 data (shear probes)|Spectra (L3_spectra)]]
#* raw and cleaned spectra
# [[Level 4 data (shear probes)|Dissipation <math>\varepsilon</math> estimates (L4_dissipation)]]
#* dissipation estimates and corresponding quality parameter as time series

-------------------
return to [[Shear probes]]

[[Category:Shear probes]]

Isotropic turbulence

2023-09-04T12:57:39Z

Ilker:

{{DefineConcept
|description=Turbulence properties are independent of direction
|article_type=Fundamentals
}}

A state whereby the velocity components and their derivatives are independent of direction. If this is not the case the turbulence is said to be [[Anisotropic turbulence|anisotropic]].

The largest scale eddies of a turbulent flow contain the bulk of the turbulence kinetic energy of the flow.
These eddies tend to be somewhat organized, and their shape and size reflect the physical boundaries and other characteristics of the flow. The large eddies break down into smaller eddies through flow interactions and they eventually reach a size at which they tend to be isotropic – they do not have a preferred orientation and appear similar from all points of view. For isotropic turbulence, the irreversible rate of dissipation of the turbulence kinetic energy through viscous friction, ϵ, is related to the variance of any component of the (rate of) strain or the (rate of) shear, by<br>
<math>
\begin{equation}
\varepsilon =15\nu \overline{\left(\frac{\partial u}{\partial x} \right)^2} = \frac{15}{2} \nu \overline{\left(\frac{\partial u}{\partial z} \right)^2}
\label{eq:epsilon_1}
\end{equation}
</math> <br>
where <math>\partial u/\partial x</math> is any one of the three-components of strain, <math>\partial u/\partial z</math> is any one of the six components of shear, <math>\nu</math> is the kinematic viscosity, and the overline denotes a spatial average <ref>Taylor, G. I. (1935). Statistical theory of turbulence. Proceedings of the Royal Society of London. Series A-Mathematical and Physical Sciences, 151(873), 421-444. </ref>.

Netcdf meta data (shear probes)

2023-08-28T10:54:11Z

Ilker:

Netcdf meta data (shear probes)

2023-08-28T10:04:27Z

Ilker:

Flow chart for shear probes

2023-08-28T09:57:36Z

Ilker:

The processing of shear-probe data can be divided into the following five major steps and these steps apply to data collected with any platform or vehicle. There are many sub-steps to these major steps. The major steps are:

__TOC__

== Conversion to physical units ==
<div class="mw-collapsible" id="physical units" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
As a first step, the raw binary data needs to be transformed into physical units.
:* [[Determine the speed of profiling]] of the shear-probe through the water.
:* [[Determine the temperature of the water]].
:* [[Convert the shear probe data]] samples into physical units
:* Convert all other signals per the recommendations of the manufacturer of the sensor or instruments that produce these signals.
</div>

Please note that most choices made must be included in a data set, as described
in the [[Netcdf meta data (shear probes)|list of meta data]].

== "Section" selection ==
<div class="mw-collapsible" id="Section" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
Before you can process your shear-probe data to derive the rate of dissipation you must select the [[section]] of data that you wish to process. For a vertically profiling instrument, this is traditionnally referred to as a "profile". We adopt the term "section" as this is platform independent and will include time series for dissipation estimates along horizontal or slanted trajectories as well as from moored shear probes. You must make sure that the selection is meaningful and sensible. For example, the shear probe must be profiling through the water with a speed, direction, and orientation that is fairly stationary. The selection of data can be partially automated by requiring that the kinematics of your instrument achieve certain minimum criteria. The steps to section selection are as follows:
:* Choose the [[minimum speed]] of profiling.
:* Choose the [[direction of the vertical velocity]] of the profiler.
:* Choose the [[minimum depth]].
:* Choose the [[maximum pitch and roll]] of the profiler.
:* Choose the [[minimum duration]] over which the [[minimum speed]] through [[maximum pitch and roll]] must be satisfied.

Please note that most choices made must be included in a data set, as described
in the [[Netcdf meta data (shear probes)|list of meta data]].

</div>

== Choosing the [[processing parameters]] ==
<div class="mw-collapsible" id="processing parameters" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
:* Choose the length of data (in meters) used for each dissipation estimate – [[diss-length]].
:* Choose the lowest wavenumber of spectral estimation – [[fft-length]].
:* Translate [[diss-length]] and [[fft-length]] into [[duration]] (time).
:* Round these up to [[nearest power-of-two number]] of samples.
:* Choose a [[high-pass filter cut-off frequency]] to be consistent with duration of the [[fft-length]].
:* Choose [[de-spiking parameters]].
:* Choose [[vibration-coherent noise removal]].

Please note that most choices made must be included in a data set, as described
in the [[Netcdf meta data (shear probes)|list of meta data]].

</div>

== Compute the [[dissipation rate estimates]] ==

<div class="mw-collapsible" id="estimates" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
The following steps are recommended to obtain estimates of the turbulent dissipation rate of kinetic energy (<math>\varepsilon</math>).

# Extract the section to estimate dissipation time series ("Section" selection).
# High-pass filter the shear-probe and (optionally) the vibration data.
# Identify each diss-length segment in the section.
# [[De-spike the shear-probe data]], and track the fraction of data affected by de-spiking within each diss-length segment. This will become a [[Shear_probes_quality_control_metrics|quality-control metric]].
# Calculate the [[frequency spectra and cross-spectra of shear and vibrations]] for each diss-length segment.
# Extract the original and the vibration-coherent clean shear-probe frequency spectra with [[the Goodman algorithm]].
# Correct shear and vibration frequency spectra for [[the high-pass filter]].
# Correct the cleaned frequency spectra for [[the bias induced by the Goodman algorithm]].
# Convert the frequency spectra into wavenumber spectra using the mean speed, <math>U</math>, for each diss-length segment. That is, make the wavenumber <math>k=f/U</math> and the spectrum <math>E(k)=UE(f)</math> .
# Correct the spectra of shear for the [[wavenumber response of the shear probe]].
# Apply an [[iterative spectral integration algorithm]] to estimate the variance of shear.
# Calculate the turbulent dissipation rate by multiplying the shear variance by <math>\frac{15}{2}\nu</math> where <math>\nu </math> is the temperature-dependent kinematic viscosity.
# Determine the [[figure of merit (FM)]] for each shear-probe spectrum.
# Calculate the expected variance of each dissipation estimate.

Please note that most choices made must be included in a data set, as described
in the [[Netcdf meta data (shear probes)|list of meta data]].

</div>

== Apply [[Shear_probes_quality_control_metrics|quality-control metrics]] ==

<div class="mw-collapsible" id="quality_control" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
Shear-probe data can be corrupted or compromised in several different ways.
These include but are not limited to (''i'') collision with plankton and other materials, (''ii'') unremovable vibrational contamination. (''iii'') electronic noise, and (''iv'') interference from other instrumentation on a platform that carries the shear probes.
This section describes the quality control metrics and the coding used to [[Quality_control_coding|identify]] them.
Quality-control metrics that are currently identified include;

:* [[figure of merit (FM)]]
:* [[fraction of shear-probe data altered by the de-spiking routine]]
:* number of [[iterations]] of the de-spiking routine required to clean the data
:* [[agreement between dissipation estimates]] from redundant sensors (i.e. two or more shear probes)

The numerical threshold for these metrics should depend, as much as possible, on the known statistical properties of a turbulence shear measurement.
The numerical values of the QC codes (or flags) is found in [[Quality_control_coding|QC-flags]].

Please note that most choices made must be included in a data set, as described
in the [[Netcdf meta data (shear probes)|list of meta data]].

</div>
--------------------
Return to [[ Shear probes | Shear Probe Welcome Page]]
[[Category: Shear probes]]

Flow chart for shear probes

2023-08-28T09:55:27Z

Ilker:

The processing of shear-probe data can be divided into the following five major steps and these steps apply to data collected with any platform or vehicle. There are many sub-steps to these major steps. The major steps are:

__TOC__

== Conversion to physical units ==
<div class="mw-collapsible" id="physical units" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
As a first step, the raw binary data needs to be transformed into physical units.
:* [[Determine the speed of profiling]] of the shear-probe through the water.
:* [[Determine the temperature of the water]].
:* [[Convert the shear probe data]] samples into physical units
:* Convert all other signals per the recommendations of the manufacturer of the sensor or instruments that produce these signals.
</div>

Please note that most choices made must be included in a data set, as described
in the [[Netcdf meta data (shear probes)|list of meta data]].

== "Section" selection ==
<div class="mw-collapsible" id="Section" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
Before you can process your shear-probe data to derive the rate of dissipation you must select the [[section]] of data that you wish to process. For a vertically profiling instrument, this is traditionnally referred to as a "profile". We adopt the term "section" as this is platform independent and will include time series for dissipation estimates along horizontal or slanted trajectories as well as from moored shear probes. You must make sure that the selection is meaningful and sensible. For example, the shear probe must be profiling through the water with a speed, direction, and orientation that is fairly stationary. The selection of data can be partially automated by requiring that the kinematics of your instrument achieve certain minimum criteria. The steps to section selection are as follows:
:* Choose the [[minimum speed]] of profiling.
:* Choose the [[direction of the vertical velocity]] of the profiler.
:* Choose the [[minimum depth]].
:* Choose the [[maximum pitch and roll]] of the profiler.
:* Choose the [[minimum duration]] over which the [[minimum speed]] through [[maximum pitch and roll]] must be satisfied.
</div>

== Choosing the [[processing parameters]] ==
<div class="mw-collapsible" id="processing parameters" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
:* Choose the length of data (in meters) used for each dissipation estimate – [[diss-length]].
:* Choose the lowest wavenumber of spectral estimation – [[fft-length]].
:* Translate [[diss-length]] and [[fft-length]] into [[duration]] (time).
:* Round these up to [[nearest power-of-two number]] of samples.
:* Choose a [[high-pass filter cut-off frequency]] to be consistent with duration of the [[fft-length]].
:* Choose [[de-spiking parameters]].
:* Choose [[vibration-coherent noise removal]].
</div>

== Compute the [[dissipation rate estimates]] ==

<div class="mw-collapsible" id="estimates" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
The following steps are recommended to obtain estimates of the turbulent dissipation rate of kinetic energy (<math>\varepsilon</math>).

# Extract the section to estimate dissipation time series ("Section" selection).
# High-pass filter the shear-probe and (optionally) the vibration data.
# Identify each diss-length segment in the section.
# [[De-spike the shear-probe data]], and track the fraction of data affected by de-spiking within each diss-length segment. This will become a [[Shear_probes_quality_control_metrics|quality-control metric]].
# Calculate the [[frequency spectra and cross-spectra of shear and vibrations]] for each diss-length segment.
# Extract the original and the vibration-coherent clean shear-probe frequency spectra with [[the Goodman algorithm]].
# Correct shear and vibration frequency spectra for [[the high-pass filter]].
# Correct the cleaned frequency spectra for [[the bias induced by the Goodman algorithm]].
# Convert the frequency spectra into wavenumber spectra using the mean speed, <math>U</math>, for each diss-length segment. That is, make the wavenumber <math>k=f/U</math> and the spectrum <math>E(k)=UE(f)</math> .
# Correct the spectra of shear for the [[wavenumber response of the shear probe]].
# Apply an [[iterative spectral integration algorithm]] to estimate the variance of shear.
# Calculate the turbulent dissipation rate by multiplying the shear variance by <math>\frac{15}{2}\nu</math> where <math>\nu </math> is the temperature-dependent kinematic viscosity.
# Determine the [[figure of merit (FM)]] for each shear-probe spectrum.
# Calculate the expected variance of each dissipation estimate.
</div>

== Apply [[Shear_probes_quality_control_metrics|quality-control metrics]] ==

<div class="mw-collapsible" id="quality_control" data-collapsetext="Collapse" data-expandtext="Expand">
<br>
Shear-probe data can be corrupted or compromised in several different ways.
These include but are not limited to (''i'') collision with plankton and other materials, (''ii'') unremovable vibrational contamination. (''iii'') electronic noise, and (''iv'') interference from other instrumentation on a platform that carries the shear probes.
This section describes the quality control metrics and the coding used to [[Quality_control_coding|identify]] them.
Quality-control metrics that are currently identified include;

:* [[figure of merit (FM)]]
:* [[fraction of shear-probe data altered by the de-spiking routine]]
:* number of [[iterations]] of the de-spiking routine required to clean the data
:* [[agreement between dissipation estimates]] from redundant sensors (i.e. two or more shear probes)

The numerical threshold for these metrics should depend, as much as possible, on the known statistical properties of a turbulence shear measurement.
The numerical values of the QC codes (or flags) is found in [[Quality_control_coding|QC-flags]].

</div>
--------------------
Return to [[ Shear probes | Shear Probe Welcome Page]]
[[Category: Shear probes]]

Quality control coding

2023-08-28T09:18:00Z

Ilker:

'''[In progress]
'''

'''Shear-probe quality-control flags'''

The Q (quality control) flags associated with shear-probe measurements are bitwise flags with boolean values which are CF compliant. More information available here: https://mplnet.gsfc.nasa.gov/about-flags

Every dissipation estimate from every probe must have Q flag.
The numerical values of the Q flags are as follows:

{| class="wikitable"
|-
! Flag Mask
! Bit
! Flag Meaning
! Example threshold value
| Ex: True =1 / False =0
| Ex: Q value
|-
| 1
| Bit 0
| Poor figure of merit
| 1.15
| 0
| 0
|-
| 2
| Bit 1
| Large fraction of data with spikes
| 5%
| 0
| 0
|-
| 4
| Bit 2
| Anomalously large disagreement between dissipation estimates from probes
| 2.772
| 1
| 4
|-
| 8
| Bit 3
| Too many iterations of despiking routine
| 8
| 0
| 0
|-
| 16
| Bit 4
| Insufficient variance resolved
| 50%
| 1
| 16
|-
| 32
| Bit 5
| manual flag to be defined by user
| N/A
| 0
| 0
|-
| 64
| Bit 6
| manual flag to be defined by user
| N/A
| 0
| 0
|-
| 128
| Bit 7
| manual flag to be defined by user
| N/A
| 0
| 0
|-
|
|
|
|
|
| Final Q = 20
|}

<br />

The Q flags are combined by their addition.
For example a Q value of 20 means that the dissipation estimated failed both dissipation ratio limit test and the resolved variance test.
A value of 255 means that all tests failed.
The reasons for a failure can be decoded by breaking the value of Q down to its powers of 2.

-----------------------------
return to [[Flow chart for shear probes]]

[[Category: Shear probes]]

Quality control coding

2023-08-28T09:17:47Z

Ilker:

'''[In progress]
'''

'''Shear-probe quality-control flags'''

The Q (quality control) flags associated with shear-probe measurements are bitwise flags with boolean values which are CF compliant. More information available here: https://mplnet.gsfc.nasa.gov/about-flags

Every dissipation estimate from every probe must have Q flag.
The numerical values of the Q flags are as follows:

{| class="wikitable"
|-
! Flag Mask
! Bit
! Flag Meaning
! Example threshold value
| Ex: True =1 / False =0
| Ex: Q value
|-
| 1
| Bit 0
| Poor figure of merit
| 1.05
| 0
| 0
|-
| 2
| Bit 1
| Large fraction of data with spikes
| 5%
| 0
| 0
|-
| 4
| Bit 2
| Anomalously large disagreement between dissipation estimates from probes
| 2.772
| 1
| 4
|-
| 8
| Bit 3
| Too many iterations of despiking routine
| 8
| 0
| 0
|-
| 16
| Bit 4
| Insufficient variance resolved
| 50%
| 1
| 16
|-
| 32
| Bit 5
| manual flag to be defined by user
| N/A
| 0
| 0
|-
| 64
| Bit 6
| manual flag to be defined by user
| N/A
| 0
| 0
|-
| 128
| Bit 7
| manual flag to be defined by user
| N/A
| 0
| 0
|-
|
|
|
|
|
| Final Q = 20
|}

<br />

The Q flags are combined by their addition.
For example a Q value of 20 means that the dissipation estimated failed both dissipation ratio limit test and the resolved variance test.
A value of 255 means that all tests failed.
The reasons for a failure can be decoded by breaking the value of Q down to its powers of 2.

-----------------------------
return to [[Flow chart for shear probes]]

[[Category: Shear probes]]

Netcdf meta data (shear probes)

2023-08-28T08:44:47Z

Ilker:

Agreement between dissipation estimates

2023-08-03T09:49:49Z

Ilker:

When two or more shear probes, in close proximity, are used to collect simultaneous data, the rate of dissipation derived from such data will not agree exactly.
Even for nearly flawless measurements, there will be disagreement for purely statistical reasons.
Measuring a turbulent shear is sampling a statistical process.
The sample variance will differ from the population variance and this difference will reduce with the increasing length of data in the sample.
The sampling uncertainty is distributed log-normally with a variance of

<math> \sigma^2_{\ln\varepsilon} = \frac{5.5}{1 + \left(\hat{L}_f/4\right)^{7/9}}\ \ ,\ \ \hat{L}_f \equiv \hat{L} V_f^{3/4} = \frac{L}{L_K} V_f^{3/4} </math>

where <math>L_K=\left(\nu^3/\varepsilon \right)^{1/4}</math> is the Kolmogorov length, and <math>V_f</math> is the fraction of the shear variance that is resolved by terminating the spectral integration at an upper wavenumber of <math>k_u</math><ref name=“Lueck2022a”> Lueck, R. G., 2022a: The statistics of oceanic turbulence measurements. Part 1: Shear variance and dissipation rates. J. Atmos. Oceanic Technol., –, in press, doi:--.</ref>. The <math>L</math> is the physical length of data, in m, used for producing the <math>\varepsilon</math> estimate.

The 95% confidence interval on an individual dissipation estimate, <math>\varepsilon_1</math> is thus

<math> \mathrm{CF_{95}}(\varepsilon_1) = \varepsilon_1\, \exp\left(\pm1.96\,\sigma_{\ln\varepsilon} \right) \ \ .</math>

The 95% confidence interval for the geometric mean of a pair of dissipation estimates is

<math> \mathrm{CF_{95}} = \sqrt{\varepsilon_1\,\varepsilon_2} \, \exp\left(\pm1.96\,\sigma_{\ln\varepsilon}\sqrt{1/2} \right) \ \ .</math>

Thus, there is less than a 5% chance that the ratio of two simultaneous dissipation estimates is outside of the range of

<math> \exp\left(\pm1.96\,\sigma_{\ln\varepsilon}\,\sqrt{2} \right) \ \ .</math>

Because the rate of dissipation is not identical for a pair of probes, the estimate of the standard deviation, <math>\sigma_{\ln\varepsilon}</math>, will also differ.
But, only slightly because of the quarter-power dependence of the Kolmogorov length on the rate of dissipation.
So, one could use either the smaller of the two standard deviations or their average for the testing of the dissipation ratios. In practice, if we have two dissipation estimates, we sort them into ascending order and the natural logarithm of their ratio or the difference <math>\ln\varepsilon_2 - \ln\varepsilon_1</math>, should be less than the threshold <math>1.96\sqrt{2} = 2.772</math> times <math>\sigma_{\ln\varepsilon}</math>.

If there are more than two simultaneous dissipation estimates, then they should be sorted into ascending order.
The ratio test is first applied to the smaller and the largest dissipation estimate.
If this pair passes the test and all other pairs will also pass the ratio test.
If this pair does not pass the test, then the larger of the two should be flagged, and the test applied to the next largest (and the smallest) until a pair passes the test, or all pairs have been tested.

It is most likely that the larger of a pair of estimates is the erroneous one because signal contamination and other data flaws usually act to increase the variance of the shear=probe signal.

Very large dissipation rates require a fit to the inertial subrange in order to estimate the rate of dissipation because the shear probe will not resolve the shear variance.
In the inertial subrange, the spectrum of shear is

<math> \Psi(k) = A\, \varepsilon^{2/3}\left(2\pi\right)^2 k^{1/3}</math>

where the factor of <math>A</math> is approximately 0.2, depending on the model one wishes to use.

The sampling uncertainty of a spectrum is also distributed log-normally with a sampling variance of

<math> \sigma^2_{\ln\Psi} = \frac{5}{4}\, \left(N_f - N_V \right)^{-7/9} </math>

where <math>N_f</math> is the number of fft-segments used to estimate the spectrum and <math>N_V</math> is the number of vibration and other signals that were used to clean the shear spectrum
<ref name=“Lueck2022b”> Lueck, R. G., 2022b: The statistics of oceanic turbulence measurements. Part 2: Shear spectra and a new spectral model. J. Atmos. Oceanic Technol., –, in press, doi:--.</ref> .
Thus, dividing the spectrum (in the inertial subrange) by <math>A(2\pi)^2\, k^{1/3}</math> and taking its logarithm provides samples of <math>\ln\varepsilon^{2/3}</math> that have a population standard deviation of <math>\sigma_{\ln\Psi}</math>.
Their average has a standard deviation of <math>\sigma_{\ln\Psi}/\sqrt{N_s}</math> where <math>N_s</math> is the number of spectral values in the inertial subrange.

Thus, the 95% confidence range of the rate of dissipation derived from a fit to the logarithm of the spectrum in the inertial subrange is

<math> \mathrm{CF}_{95} = \varepsilon\, \left[\exp\left(\pm1.96\,\sigma_{\ln\Psi}/\sqrt{N_s} \right) \right]^{3/2} \ .</math>

There is less than a 5% chance that the ratio of a pair of such dissipation estimates falls outside of the range of

<math> \exp\left(\pm1.96\,(3/2)\sqrt{2}\sigma_{\ln\Psi}\,/\sqrt{N_s} \right) \ .</math>

==References==
<references />
-----------------------------
return to [[Flow chart for shear probes]]

[[Category:Shear probes]]

Section

2023-07-28T08:41:30Z

Ilker:

{{DefineConcept
|parameter_name=Section
|description=Part of a record (i.e., profile or time series) selected for analysis, e.g., to obtain a profile or time series of <math>\varepsilon</math> estimates.
|article_type=Concept
}}
==Vertical profiler example==
For example, a vertical profiler will record data continuously during the up- and down-casts but only data from one of the directions is usable. If we assume the profiler collects good data as it profiles down and it travels up and down successively five times, then we would have 5 sections of data i.e., 5 profiles.

For up-rising profilers, only the data collected on the ascent is good for turbulence analysis. So the five data sections would correspond to the upward records.

Agreement between dissipation estimates

2023-07-27T12:45:43Z

Ilker:

When two or more shear probes, in close proximity, are used to collect simultaneous data, the rate of dissipation derived from such data will not agree exactly.
Even for nearly flawless measurements, there will be disagreement for purely statistical reasons.
Measuring a turbulent shear is sampling a statistical process.
The sample variance will differ from the population variance and this difference will reduce with the increasing length of data in the sample.
The sampling uncertainty is distributed log-normally with a variance of

<math> \sigma^2_{\ln\varepsilon} = \frac{5.5}{1 + \left(\hat{L}_f/4\right)^{7/9}}\ \ ,\ \ \hat{L}_f \equiv \hat{L} V_f^{3/4} = \frac{L}{L_K} V_f^{3/4} </math>

where <math>L_K=\left(\nu^3/\varepsilon \right)^{1/4}</math> is the Kolmogorov length, and <math>V_f</math> is the fraction of the shear variance that is resolved by terminating the spectral integration at an upper wavenumber of <math>k_u</math><ref name=“Lueck2022a”> Lueck, R. G., 2022a: The statistics of oceanic turbulence measurements. Part 1: Shear variance and dissipation rates. J. Atmos. Oceanic Technol., –, in press, doi:--.</ref>. The <math>L</math> is the physical length of data, in m, used for producing the <math>\varepsilon</math> estimate.

The 95% confidence interval on an individual dissipation estimate, <math>\varepsilon_1</math> is thus

<math> \mathrm{CF_{95}}(\varepsilon_1) = \varepsilon_1\, \exp\left(\pm1.96\,\sigma_{\ln\varepsilon} \right) \ \ .</math>

The 95% confidence interval for the geometric mean of a pair of dissipation estimates is

<math> \mathrm{CF_{95}} = \sqrt{\varepsilon_1\,\varepsilon_2} \, \exp\left(\pm1.96\,\sigma_{\ln\varepsilon}\sqrt{1/2} \right) \ \ .</math>

Thus, there is less than a 5% chance that the ratio of two simultaneous dissipation estimates is outside of the range of

<math> \exp\left(\pm1.96\,\sigma_{\ln\varepsilon}\,\sqrt{2} \right) \ \ .</math>

Because the rate of dissipation is not identical for a pair of probes, the estimate of the standard deviation, <math>\sigma_{\ln\varepsilon}</math>, will also differ.
But, only slightly because of the quarter-power dependence of the Kolmogorov length on the rate of dissipation.
So, one could use either the smaller of the two standard deviations or their average for the testing of the dissipation ratios. In practice, if we have two dissipation estimates, we sort them into ascending order and the natural logarithm of their ratio or the difference <math>\ln\varepsilon_2 - \ln\varepsilon_1</math>), should be less than the threshold <math>1.96\sqrt{2} = 2.772</math>.

If there are more than two simultaneous dissipation estimates, then they should be sorted into ascending order.
The ratio test is first applied to the smaller and the largest dissipation estimate.
If this pair passes the test and all other pairs will also pass the ratio test.
If this pair does not pass the test, then the larger of the two should be flagged, and the test applied to the next largest (and the smallest) until a pair passes the test, or all pairs have been tested.

It is most likely that the larger of a pair of estimates is the erroneous one because signal contamination and other data flaws usually act to increase the variance of the shear=probe signal.

Very large dissipation rates require a fit to the inertial subrange in order to estimate the rate of dissipation because the shear probe will not resolve the shear variance.
In the inertial subrange, the spectrum of shear is

<math> \Psi(k) = A\, \varepsilon^{2/3}\left(2\pi\right)^2 k^{1/3}</math>

where the factor of <math>A</math> is approximately 0.2, depending on the model one wishes to use.

The sampling uncertainty of a spectrum is also distributed log-normally with a sampling variance of

<math> \sigma^2_{\ln\Psi} = \frac{5}{4}\, \left(N_f - N_V \right)^{-7/9} </math>

where <math>N_f</math> is the number of fft-segments used to estimate the spectrum and <math>N_V</math> is the number of vibration and other signals that were used to clean the shear spectrum
<ref name=“Lueck2022b”> Lueck, R. G., 2022b: The statistics of oceanic turbulence measurements. Part 2: Shear spectra and a new spectral model. J. Atmos. Oceanic Technol., –, in press, doi:--.</ref> .
Thus, dividing the spectrum (in the inertial subrange) by <math>A(2\pi)^2\, k^{1/3}</math> and taking its logarithm provides samples of <math>\ln\varepsilon^{2/3}</math> that have a population standard deviation of <math>\sigma_{\ln\Psi}</math>.
Their average has a standard deviation of <math>\sigma_{\ln\Psi}/\sqrt{N_s}</math> where <math>N_s</math> is the number of spectral values in the inertial subrange.

Thus, the 95% confidence range of the rate of dissipation derived from a fit to the logarithm of the spectrum in the inertial subrange is

<math> \mathrm{CF}_{95} = \varepsilon\, \left[\exp\left(\pm1.96\,\sigma_{\ln\Psi}/\sqrt{N_s} \right) \right]^{3/2} \ .</math>

There is less than a 5% chance that the ratio of a pair of such dissipation estimates falls outside of the range of

<math> \exp\left(\pm1.96\,(3/2)\sqrt{2}\sigma_{\ln\Psi}\,/\sqrt{N_s} \right) \ .</math>

==References==
<references />
-----------------------------
return to [[Flow chart for shear probes]]

[[Category:Shear probes]]

Agreement between dissipation estimates

2023-07-27T12:40:29Z

Ilker:

When two or more shear probes, in close proximity, are used to collect simultaneous data, the rate of dissipation derived from such data will not agree exactly.
Even for nearly flawless measurements, there will be disagreement for purely statistical reasons.
Measuring a turbulent shear is sampling a statistical process.
The sample variance will differ from the population variance and this difference will reduce with the increasing length of data in the sample.
The sampling uncertainty is distributed log-normally with a variance of

<math> \sigma^2_{\ln\varepsilon} = \frac{5.5}{1 + \left(\hat{L}_f/4\right)^{7/9}}\ \ ,\ \ \hat{L}_f \equiv \hat{L} V_f^{3/4} = \frac{L}{L_K} V_f^{3/4} </math>

where <math>L_K=\left(\nu^3/\varepsilon \right)^{1/4}</math> is the Kolmogorov length, and <math>V_f</math> is the fraction of the shear variance that is resolved by terminating the spectral integration at an upper wavenumber of <math>k_u</math><ref name=“Lueck2022a”> Lueck, R. G., 2022a: The statistics of oceanic turbulence measurements. Part 1: Shear variance and dissipation rates. J. Atmos. Oceanic Technol., –, in press, doi:--.</ref>. The <math>L</math> is the physical length of data, in m, used for producing the <math>\varepsilon</math> estimate.

The 95% confidence interval on an individual dissipation estimate, <math>\varepsilon_1</math> is thus

<math> \mathrm{CF_{95}}(\varepsilon_1) = \varepsilon_1\, \exp\left(\pm1.96\,\sigma_{\ln\varepsilon} \right) \ \ .</math>

The 95% confidence interval for the geometric mean of a pair of dissipation estimates is

<math> \mathrm{CF_{95}} = \sqrt{\varepsilon_1\,\varepsilon_2} \, \exp\left(\pm1.96\,\sigma_{\ln\varepsilon}\sqrt{1/2} \right) \ \ .</math>

Thus, there is less than a 5% chance that the ratio of two simultaneous dissipation estimates is outside of the range of

<math> \exp\left(\pm1.96\,\sigma_{\ln\varepsilon}\,\sqrt{2} \right) \ \ .</math>

Because the rate of dissipation is not identical for a pair of probes, the estimate of the standard deviation, <math>\sigma_{\ln\varepsilon}</math>, will also differ.
But, only slightly because of the quarter-power dependence of the Kolmogorov length on the rate of dissipation.
So, one could use either the smaller of the two standard deviations or their average for the testing of the dissipation ratios. In practice, if we have two dissipation estimates, we sort them into ascending order and the natural logarithm of their ratio or the difference <math>\ln\varepsilon_2 - \ln\varepsilon_1</math>), should be less than the threshold <math>1.96\sqrt{2} = 2.772</math>.

If there are more than two simultaneous dissipation estimates, then they should be sorted into ascending order.
The ratio test is first applied to the smaller and the largest dissipation estimate.
If this pair passes the test and all other pairs will also pass the ratio test.
If this pair does not pass the test, then the larger of the two should be flagged, and the test applied to the next largest (and the smallest) until a pair passes the test, or all pairs have been tested.

It is most likely that the larger of a pair of estimates is the erroneous one because signal contamination and other data flaws usually act to increase the variance of the shear=probe signal.

Very large dissipation rates require a fit to the inertial subrange in order to estimate the rate of dissipation because the shear probe will not resolve the shear variance.
In the inertial subrange, the spectrum of shear is

<math> \Psi(k) = A\, \varepsilon^{2/3}\left(2\pi\right)^2 k^{1/3}</math>

where the factor of <math>A</math> is approximately 0.2, depending on the model one wishes to use.

The sampling uncertainty of a spectrum is also distributed log-normally with a sampling variance of

<math> \sigma^2_{\ln\Psi} = \frac{5}{4}\, \left(N_f - N_V \right)^{-7/9} </math>

where <math>N_f</math> is the number of fft-segments used to estimate the spectrum and <math>N_V</math> is the number of vibration and other signals that were used to clean the shear spectrum
<ref name=“Lueck2022b”> Lueck, R. G., 2022b: The statistics of oceanic turbulence measurements. Part 2: Shear spectra and a new spectral model. J. Atmos. Oceanic Technol., –, in press, doi:--.</ref> .
Thus, dividing the spectrum (in the inertial subrange) by <math>A(2\pi)^2\, k^{1/3}</math> and taking its logarithm provides samples of <math>\ln\varepsilon^{2/3}</math> that have a population standard deviation of <math>\sigma_{\ln\Psi}</math>.
Their average has a standard deviation of <math>\sigma_{\ln\Psi}/\sqrt{N_s}</math> where <math>N_s</math> is the number of spectral values in the inertial subrange.

Thus, the 95% confidence range of the rate of dissipation derived from a fit to the logarithm of the spectrum in the inertial subrange is

<math> \mathrm{CF}_{95} = \varepsilon\, \left[\exp\left(\pm1.96\,\sigma_{\ln\Psi}/\sqrt{N_s} \right) \right]^{3/2} \ .</math>

There is less than a 5% chance that the ratio of a pair of such dissipation estimates falls outside of the range of

<math> \left[\exp\left(\pm1.96\,\sigma_{\ln\Psi}\, \sqrt{2}/\sqrt{N_s} \right) \right]^{3/2} \ .</math>

==References==
<references />
-----------------------------
return to [[Flow chart for shear probes]]

[[Category:Shear probes]]

Agreement between dissipation estimates

2023-07-27T12:36:39Z

Ilker:

When two or more shear probes, in close proximity, are used to collect simultaneous data, the rate of dissipation derived from such data will not agree exactly.
Even for nearly flawless measurements, there will be disagreement for purely statistical reasons.
Measuring a turbulent shear is sampling a statistical process.
The sample variance will differ from the population variance and this difference will reduce with the increasing length of data in the sample.
The sampling uncertainty is distributed log-normally with a variance of

<math> \sigma^2_{\ln\varepsilon} = \frac{5.5}{1 + \left(\hat{L}_f/4\right)^{7/9}}\ \ ,\ \ \hat{L}_f \equiv \hat{L} V_f^{3/4} = \frac{L}{L_K} V_f^{3/4} </math>

where <math>L_K=\left(\nu^3/\varepsilon \right)^{1/4}</math> is the Kolmogorov length, and <math>V_f</math> is the fraction of the shear variance that is resolved by terminating the spectral integration at an upper wavenumber of <math>k_u</math><ref name=“Lueck2022a”> Lueck, R. G., 2022a: The statistics of oceanic turbulence measurements. Part 1: Shear variance and dissipation rates. J. Atmos. Oceanic Technol., –, in press, doi:--.</ref>. The <math>L</math> is the physical length of data, in m, used for producing the <math>\varepsilon</math> estimate.

The 95% confidence interval on an individual dissipation estimate, <math>\varepsilon_1</math> is thus

<math> \mathrm{CF_{95}}(\varepsilon_1) = \varepsilon_1\, \exp\left(\pm1.96\,\sigma_{\ln\varepsilon} \right) \ \ .</math>

The 95% confidence interval for the geometric mean of a pair of dissipation estimates is

<math> \mathrm{CF_{95}} = \sqrt{\varepsilon_1\,\varepsilon_2} \, \exp\left(\pm1.96\,\sigma_{\ln\varepsilon}\sqrt{1/2} \right) \ \ .</math>

Thus, there is less than a 5% chance that the ratio of two simultaneous dissipation estimates is outside of the range of

<math> \exp\left(\pm1.96\,\sigma_{\ln\varepsilon}\,\sqrt{2} \right) \ \ .</math>

Because the rate of dissipation is not identical for a pair of probes, the estimate of the standard deviation, <math>\sigma_{\ln\varepsilon}</math>, will also differ.
But, only slightly because of the quarter-power dependence of the Kolmogorov length on the rate of dissipation.
So, one could use either the smaller of the two standard deviations or their average for the testing of the dissipation ratios. In practice, if we have two dissipation estimates, log of their ratios (or the difference <math>|\ln\varepsilon_1 - \ln\varepsilon_2|</math>), should be less than the threshold <math>1.96\sqrt{2} = 2.772</math>.

If there are more than two simultaneous dissipation estimates, then they should be sorted into ascending order.
The ratio test is first applied to the smaller and the largest dissipation estimate.
If this pair passes the test and all other pairs will also pass the ratio test.
If this pair does not pass the test, then the larger of the two should be flagged, and the test applied to the next largest (and the smallest) until a pair passes the test, or all pairs have been tested.

It is most likely that the larger of a pair of estimates is the erroneous one because signal contamination and other data flaws usually act to increase the variance of the shear=probe signal.

Very large dissipation rates require a fit to the inertial subrange in order to estimate the rate of dissipation because the shear probe will not resolve the shear variance.
In the inertial subrange, the spectrum of shear is

<math> \Psi(k) = A\, \varepsilon^{2/3}\left(2\pi\right)^2 k^{1/3}</math>

where the factor of <math>A</math> is approximately 0.2, depending on the model one wishes to use.

The sampling uncertainty of a spectrum is also distributed log-normally with a sampling variance of

<math> \sigma^2_{\ln\Psi} = \frac{5}{4}\, \left(N_f - N_V \right)^{-7/9} </math>

where <math>N_f</math> is the number of fft-segments used to estimate the spectrum and <math>N_V</math> is the number of vibration and other signals that were used to clean the shear spectrum
<ref name=“Lueck2022b”> Lueck, R. G., 2022b: The statistics of oceanic turbulence measurements. Part 2: Shear spectra and a new spectral model. J. Atmos. Oceanic Technol., –, in press, doi:--.</ref> .
Thus, dividing the spectrum (in the inertial subrange) by <math>A(2\pi)^2\, k^{1/3}</math> and taking its logarithm provides samples of <math>\ln\varepsilon^{2/3}</math> that have a population standard deviation of <math>\sigma_{\ln\Psi}</math>.
Their average has a standard deviation of <math>\sigma_{\ln\Psi}/\sqrt{N_s}</math> where <math>N_s</math> is the number of spectral values in the inertial subrange.

Thus, the 95% confidence range of the rate of dissipation derived from a fit to the logarithm of the spectrum in the inertial subrange is

<math> \mathrm{CF}_{95} = \varepsilon\, \left[\exp\left(\pm1.96\,\sigma_{\ln\Psi}/\sqrt{N_s} \right) \right]^{3/2} \ .</math>

There is less than a 5% chance that the ratio of a pair of such dissipation estimates falls outside of the range of

<math> \left[\exp\left(\pm1.96\,\sigma_{\ln\Psi}\, \sqrt{2}/\sqrt{N_s} \right) \right]^{3/2} \ .</math>

==References==
<references />
-----------------------------
return to [[Flow chart for shear probes]]

[[Category:Shear probes]]

Benchmark datasets for shear probes

2023-06-27T09:01:06Z

Ilker:

These datasets can be accessed from a [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAgL55HqB50DQd2J11m7kl9a?dl=0|read-only dropbox folder], and will eventually be housed at the BODC center with a DOI.

{| class="wikitable sortable"
|-
! Filename Prefix
! Platform
! Instrument
! Region
! PI (ATOMIX)
! Comment
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAajUI9HIodADTYRJSfYb3ba/VMP250_TidalChannel/VMP250_TidalChannel_024.nc?dl=0 VMP250_TidalChannel_024]
| Ship
| VMP-250
| Haro Strait
| Lueck
| Intense turbulence. Large up/down drafts. Most estimates require fitting to the inertial subrange.
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAD3PcHlwHjyrMAA7er6jRG_a/EPSIFISH_BLT_NORTHATL/epsifish_epsilometer_blt_north_atl.nc?dl=0 EPSILOMETER_RockallTrough]
| Ship
| Epsilometer
| Rockall Trough
| Le Boyer
| Strong turbulence in a canyon
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AABKhtIRZSuuZSfwTJ3xNNaNa/VMP2000_FaroeBankChannel/VMP2000_FaroeBankChannel.nc?dl=0 VMP2000_FaroeBankChannel]
| Ship
| VMP-2000
| Faroe Bank Channel (North Atlantic)
| Fer
| ranging from quiescent mid-water to turbulent, deep gravity current
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAniGJlY-bwRplaiAV8AxC2a/MSS_BalticSea/MSS_Baltic_0330.nc?dl=0 MSS_BalticSea]
| Ship
| MSS
| Baltic Sea
| Holtermann
|
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AADqZw8zwf93HpZMhF8MWAd-a/Nemo_MR1000_Minas_Passage/Nemo_MR1000_Minas_Passage_InStream.nc?dl=0 Nemo_MR1000_Minas_Passage_InStream]
| Mooring
| MicroRider
| Minas Passage (Bay of Fundy, NS)
| Lueck
| a swift tidal channel. Dissipation estimated from the inertial subrange
|-
|}

[[Category: Shear probes]]

-------------------------
return to [[Shear probes]] <br><br>
ATOMIX members: see also [[Tentative benchmarks for shear probes| tentative benchmarks for testers]]

Benchmark datasets for shear probes

2023-06-27T08:59:25Z

Ilker:

These datasets can be accessed from a [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAAgL55HqB50DQd2J11m7kl9a?dl=0|read-only dropbox folder], and will eventually be housed at the BODC center with a DOI.

{| class="wikitable sortable"
|-
! Filename Prefix
! Platform
! Instrument
! Region
! PI (ATOMIX)
! Comment
|-
| [https://www.dropbox.com/s/f4xwv0okps2qn6x/VMP250_TidalChannel_024.nc?dl=0 VMP250_TidalChannel_024]
| Ship
| VMP-250
| Haro Strait
| Lueck
| Intense turbulence. Large up/down drafts. Most estimates require fitting to the inertial subrange.
|-
| [https://www.dropbox.com/sh/ybbpauv5e2n8xyp/AAD3PcHlwHjyrMAA7er6jRG_a/EPSIFISH_BLT_NORTHATL/epsifish_epsilometer_blt_north_atl.nc?dl=0 EPSILOMETER_RockallTrough]
| Ship
| Epsilometer
| Rockall Trough
| Le Boyer
| Strong turbulence in a canyon
|-
| [https://www.dropbox.com/s/aes2p2g22x9c1mx/VMP2000_FaroeBankChannel.nc?dl=0 VMP2000_FaroeBankChannel]
| Ship
| VMP-2000
| Faroe Bank Channel (North Atlantic)
| Fer
| ranging from quiescent mid-water to turbulent, deep gravity current
|-
| [https://www.dropbox.com/s/sc7x05tmpuzkg8n/MSS_Baltic_0330.nc?dl=0 MSS_BalticSea]
| Ship
| MSS
| Baltic Sea
| Holtermann
|
|-
| [https://www.dropbox.com/s/gjf0flqa8ks6wug/Nemo_MR1000_Minas_Passage_InStream.nc?dl=0 Nemo_MR1000_Minas_Passage_InStream]
| Mooring
| MicroRider
| Minas Passage (Bay of Fundy, NS)
| Lueck
| a swift tidal channel. Dissipation estimated from the inertial subrange
|-
|}

[[Category: Shear probes]]

-------------------------
return to [[Shear probes]] <br><br>
ATOMIX members: see also [[Tentative benchmarks for shear probes| tentative benchmarks for testers]]