OceanPressureToDepth

Convert an ocean pressure variable (Pa) to depth below surface (m). This uses the latitude-dependent formulation of Fofonoff and Millard (1983) as given in equation 3 of https://archimer.ifremer.fr/doc/00447/55889/57949.pdf

Required input parameters:

pressure variable

The variable containing the ocean pressure values. (Note that it accepts a variable name from the user because the pressure values might be in a non-obvious variable, e.g. ObsValue/height. However, the latitude is always assumed to be in MetaData/latitude.) There are no optional input parameters.

Example configuration:

Here is an example that assigns to DerivedObsValue/depthBelowWaterSurface, the depth computed by the ObsFunction, in locations where MetaData/argo_identifier is not missing. It takes the ocean pressure from ObsValue/height.

- filter: Variable Assignment  # calculate cool-skin correction
  where:
  - variable:
      name: MetaData/argo_identifier
    is_defined:
  assignments:
  - name: DerivedObsValue/depthBelowWaterSurface
    type: float
    function:
      name: ObsFunction/OceanPressureToDepth
      options:
        pressure variable: ObsValue/height