Level 2 data, that is saved in the NetCDF group "L2_cleaned", are the full resolution, cleaned and despiked parameters from level 1. The initial data set is subdivided in sections and labeled accordingly in the parameter SECTION_NUMBER with integers. Level 2 data is ready for estimating spectra. In addition to cleaned and despiked level 1 data channels, level 2 data comprises the additional parameter summarized in the table below.
It is important that the platform speed with respect to water, as used in the dissipation estimates, is included in this level. Also note that the shear probe time series (and optionally acceleration and vibration) must be cleaned and filtered as needed at this level, and will not be altered further when estimating dissipation rates.
On all levels, "sea_water" in the standard name can be replaced by "water" for limnologic applications.
Dimensions
| Dimension short name |
description
|
| TIME [math]\displaystyle{ ^a }[/math] |
length of the record from turbulence (fast) data channels
|
| N_SHEAR_SENSORS |
number of shear channel (shear sensors)
|
| N_***_SENSORS [math]\displaystyle{ ^b }[/math] |
number of *** channel (sensors)
|
[math]\displaystyle{ ^a }[/math] At this level platform speed must be provided. We require that this is given at the shear probe time (not TIME_SLOW or TIME_CTD. Please interpolate if needed.
[math]\displaystyle{ ^b }[/math] Please use these examples for related sensors, e.g.:
N_VIB_SENSORS for vibration (piezo-acceleration) sensors
N_ACC_SENSORS for vibration acceleration sensors
Required Variables
Pressure? Or more importantly the speed past the sensor
| Parameter Name |
Standard Name |
Units of measurement |
dimension
|
| SECTION_NUMBER |
|
dimensionless |
TIME
|
| TIME |
time |
CF-Conventions compatible offset[math]\displaystyle{ ^a }[/math] |
TIME
|
| SHEAR |
sea_water_velocity_shear |
s-1 |
[TIME, N_SHEAR_SENSORS]
|
| PSPD_REL |
platform_speed_wrt_sea_water |
m s-1 |
TIME
|
[math]\displaystyle{ ^a }[/math] i.e. "Days since YYYY-MM-DDT00:00:00Z"
Optional Level 2 Variables
| Parameter Name |
Standard Name |
Units of measurement |
dimension
|
| VIB |
platform_vibration |
NA |
[TIME, N_VIB_SENSORS]
|
| ACC |
platform_acceleration |
m s-2 |
[TIME [math]\displaystyle{ ^a }[/math], N_ACC_SENSORS]
|
[math]\displaystyle{ ^a }[/math] If using TIME_SLOW or TIME_ACC, this must be provided in addition to the TIME record.
Return Dataset requirements for shear probes
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go to next: Level 3 data.
