Level 4 data (shear probes)

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. 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

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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

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Parameter Name	Standard Name	Units of measurement	dimensions
TIME	time	CF-Conventions compatible offset[math]\displaystyle{ ^a }[/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.

Optional Level 4 Variables

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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]

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