Level 4 data (velocity profilers)

Page status: Draft
Author(s):	Cynthia
Reviewer(s):
Comment:

This will dictate the data required at the final processing level, where we store the estimated dissipation estimates [math]\displaystyle{ \varepsilon }[/math] along with quality metrics.

Dimensions

Short name	Standard name	Dimensions	Comments
TIME	time	TIME	Units in Days since 1950-01-01T00:00:00Z. Provide a bounds attribute to designate the variable containing the limits of each segment (see CF-compliant example).
R_DIST	distance_from_sensor_along_beams	R_DIST	Along-beam bin centre distance (in meters) from the transducer
N_BEAM	unique_identifier_for_each_beam	N_BEAM	Array of 1 to number of beams (3 to 5 typically)
Optional dimensions for 5-beam ADCP
R_DIST5	distance_from_sensor_along_beam_5	R_DIST5	Along-beam bin centre distance (in meters) from the transducer for the 5th vertical beam

Variables

Short name	Standard name	Dimensions	Comment
EPSI	specific_turbulent_kinetic_energy_ dissipation_in_water	TIME, R_DIST, N_BEAM	Dissipation rate of turbulent kinetic energy per unit mass of water [W/kg] estimated from individual beams.
EPSI_FLAGS	specific_turbulent_kinetic_energy_ dissipation_in_water_status_flags	TIME, R_DIST, N_BEAM	To be linked, when boolean flags defined
EPSI_FINAL	specific_turbulent_kinetic_energy_ dissipation_in_water	TIME, N_BEAM	Final dissipation rate of turbulent kinetic energy per unit mass of water (beam-averaged). best to state cell_methods attribute to indicate what was averaged e.g., "cell_methods= N_BEAM:mean" for averages across beams.
N_SEGMENT	unique_identifier_for_each_segment_ in_the_entire_available_timeseries	TIME	Enables backtracking to previous processing level
BURST_NUMBER [math]\displaystyle{ \dagger\dagger }[/math]	unique_identifier_for_each_burst	TIME	Only required when measuring in burst-mode. Integers of 1, 2, etc to designate which burst the velocities are associated with.
Optional dimensions for 5-beam ADCP
ENter variables here (note N_BEAM disappears as a dimension)		TIME, R_DIST5
[math]\displaystyle{ \dagger\dagger }[/math] Variable required only when measuring in bursts e.g., 18 min of continuous measurements every hour.

---

Return to Level 3 structure function

Go back to the beginning Dataset requirements for ADCP structure function