Level 2 data (shear probes)

Level 2 data 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
go to previous: Level 1 data
go to next: Level 3 data.