Level 4 data (shear probes)

From Atomix
Revision as of 08:48, 27 September 2022 by PeterHoltermann (talk | contribs)

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 QC flags) at that depth.


Dimensions


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)

Required Variables


Parameter Name Standard Name Units of measurement dimensions
TIME time CF-Conventions compatible offset[math]\displaystyle{ ^c }[/math] TIME_SPECTRA
SECTION_NUMBER - TIME_SPECTRA
PSPD_REL flow_past_sensor 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]
EPSI_FLAGS [math]\displaystyle{ ^a }[/math] dissipation_qc_flags - [TIME_SPECTRA, N_SHEAR_SENSORS]
METHOD [math]\displaystyle{ ^b }[/math] method_used_for_estimating_ turbulent_kinetic_energy_dissipation - [TIME_SPECTRA, N_SHEAR_SENSORS]

[math]\displaystyle{ ^a }[/math] Quality control coding for the final dissipation estimate.

[math]\displaystyle{ ^b }[/math] METHOD=0 for spectral integration, METHOD=1 for fitting to the inertial subrange.

[math]\displaystyle{ ^c }[/math] i.e. "Days since YYYY-MM-DDT00:00:00Z"

Optional Level 4 Variables


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]



Return Dataset requirements for shear probes
go to previous: Level 3 data.