Contents
USAGE:
geo_strf_Cunningham = gsw_geo_strf_Cunningham(SA,CT,p,p_ref)
DESCRIPTION:
Calculates the Cunningham geostrophic streamfunction (see Eqn. (3.29.2)
of IOC et al. (2010)). This is the geostrophic streamfunction for the
difference between the horizontal velocity at the pressure concerned,
p, and the horizontal velocity on the pressure surface, p_ref. This
function calculates specific volume anomaly using the computationally
efficient 48-term expression for specific volume of McDougall et al. (2011).
Note that p_ref, is the reference pressure to which the streamfunction
is referenced. When p_ref is zero, "gsw_geo_strf_Cunningham" returns
the Cunningham geostrophic streamfunction with respect to the sea
surface, otherwise, the function returns the geostrophic streamfunction
with respect to the (deep) reference pressure p_ref.
Note that the 48-term equation has been fitted in a restricted range of
parameter space, and is most accurate inside the "oceanographic funnel"
described in McDougall et al. (2011). The GSW library function
"gsw_infunnel(SA,CT,p)" is avaialble to be used if one wants to test if
some of one's data lies outside this "funnel".
INPUT:
SA = Absolute Salinity [ g/kg ]
CT = Conservative Temperature [ deg C ]
p = sea pressure [ dbar ]
( i.e. absolute pressure - 10.1325 dbar )
p_ref = reference pressure [ dbar ]
( i.e. reference absolute pressure - 10.1325 dbar )
SA & CT need to have the same dimensions.
p may have dimensions Mx1 or 1xN or MxN, where SA & CT are MxN.
p_ref needs to be a single value, it can have dimensions 1x1 or Mx1 or
1xN or MxN.
OUTPUT:
geo_strf_Cunningham = Cunningham geostrophic streamfunction [ m^2/s^2 ]
EXAMPLE:
SA = [34.7118; 34.8915; 35.0256; 34.8472; 34.7366; 34.7324;]
CT = [28.8099; 28.4392; 22.7862; 10.2262; 6.8272; 4.3236;]
p = [ 10; 50; 125; 250; 600; 1000;]
p_ref = 1000
geo_strf_Cunningham = gsw_geo_strf_Cunningham(SA,CT,p,p_ref)
geo_strf_Cunningham =
17.893004502475378
17.819966326875146
16.224154546318459
11.382163183421653
9.576877475752553
7.122260539475974
AUTHOR:
Trevor McDougall and Paul Barker [ help@teos-10.org ]
VERSION NUMBER:
3.01 (16th May, 2011)
REFERENCES:
Cunningham, S.A., 2000: Circulation and volume flux of the North
Atlantic using syoptic hydrographic data in a Bernoulli inverse.
J. Marine Res., 58, 1-35.
IOC, SCOR and IAPSO, 2010: The international thermodynamic equation of
seawater - 2010: Calculation and use of thermodynamic properties.
Intergovernmental Oceanographic Commission, Manuals and Guides No. 56,
UNESCO (English), 196 pp. Available from the TEOS-10 web site.
See section 3.29 of this TEOS-10 Manual.
McDougall T.J., P.M. Barker, R. Feistel and D.R. Jackett, 2011: A
computationally efficient 48-term expression for the density of
seawater in terms of Conservative Temperature, and related properties
of seawater. To be submitted to Ocean Science Discussions.
The software is available from http://www.TEOS-10.org
