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depth_to_pres

Convert ocean depth to pressure.

Available in version 6.1.0 and later.

Prototype

	function depth_to_pres (
		z       : numeric,  
		opt [1] : logical   
	)

	return_val  :  numeric

Arguments

Ocean depth (meters)

opt

Options. Currently not used, set to False.

Return value

The returned array will have units of bars. It will be the same size, shape and type as z.

Description

Calculate ocean pressure (bars) from user specified depth (meters). The equation used is consistent with that used in the POP model (2012).

This function computes pressure in dekabar from depth in meters using a mean density derived from depth-dependent global average temperatures and salinities from Levitus 1994, and integrating using hydrostatic balance.

References

 
      Levitus, S., R. Burgett, and T.P. Boyer, 1994
      World Ocean Atlas 
      Volume 3: Salinity, NOAA Atlas NESDIS 3, US Dept. of Commerce
 
      Dukowicz, J. K., 2000 
      Reduction of Pressure and Pressure
      Gradient Errors in Ocean Simulations, J. Phys. Oceanogr.,

Examples

Example 1

       d    = (/ 7321.45, 9712.65/)                     ; meters
       pd   = depth_to_pres(d,False) ; pd = (/ 749.937, 1000.19/) bars

Example 2

       f        = addfile("POP.nc", "r")
       z        = f->z_t            ; cm
       z        = z*0.01            ; convert to meters
       z@units  = "meters"

       pz       = depth_to_pres(z,False)        ; pz(kz); kz=dimsizes(z)
       pz@units = "bars"

The output: