# gsw_geo_strf_dyn_height_1: Geostrophic Dynamic Height Anomaly (provisional version) In gsw: Gibbs Sea Water Functions

## Description

This calculates a geopotential anomaly, called either the dynamic height anomaly or the geostrophic streamfunction in the TEOS-10 document listed as  below.

To get the column-integrated value in meters, take the first value of the returned vector and divide by 9.7963m/s^2. Note that this yields an integral with the top measured pressure (not zero) as an upper limit.

## Usage

 `1` ```gsw_geo_strf_dyn_height_1(SA, CT, p, p_ref = 0, max_dp = 1, interp_method = 2) ```

## Arguments

 `SA` Absolute Salinity [ g/kg ] `CT` Conservative Temperature [ degC ] `p` sea pressure [dbar], i.e. absolute pressure [dbar] minus 10.1325 dbar `p_ref` reference pressure [dbar], i.e. absolute pressure [dbar] minus 10.1325 dbar `max_dp` numeric value indicating the maximum tolerated pressure separation between levels. If any pressure step exceeds `max_dp`, then a uniform grid is constructed with `max_dp` as the interval. `interp_method` integer specifying interpolation scheme (1 for linear, 2 for pchip)

## Details

Because of the scheme used in the underlying C code, the pressures must be in order, and must not have any repeats. Also, there must be at least 4 pressure values. Violating any of these restrictions yields an error.

If `p_ref` exceeds the largest `p` value, a vector of zeros is returned, in accordance with the underlying C code.

## Value

A vector containing geopotential anomaly in m^2/s^2 for each level. For more on the units, see .

## Implementation Note

This R function uses a wrapper to a C function contained within the GSW-C system as updated 2021-03-27 at https://github.com/TEOS-10/GSW-C with git commit 'f7bfebf44f686034636facb09852f1d5760c27f5'. In turn, that C function uses data from the `library/gsw_data_v3_0.mat` file provided in the GSW-Matlab source code, version 3.06-11. Unfortunately, this version is no longer displayed on the TEOS-10.org website. Therefore, in the interests of making GSW-R be self-contained, a copy was downloaded from http://www.teos-10.org/software/gsw_matlab_v3_06_11.zip on 2021-0706, the .mat file was stored in the developer/create_data directory of https://github.com/TEOS-10/GSW-R, and then the dataset used in GSW-R was created based on that .mat file. Please consult http://www.teos-10.org to learn more about the various TEOS-10 software systems.

## References

2. Talley et al., 2011. Descriptive Physical Oceanography, Edition 6, Elsevier.

## Examples

 ```1 2 3 4 5 6 7 8``` ```SA <- c(34.7118, 34.8915, 35.0256, 34.8472, 34.7366, 34.7324) CT <- c(28.8099, 28.4392, 22.7862, 10.2262, 6.8272, 4.3236) p <- c( 10, 50, 125, 250, 600, 1000) p_ref <- 1000 dh <- gsw_geo_strf_dyn_height_1(SA, CT, p, p_ref, 1, 2) ## FIXME: The following test values fail. ## all.equal(dh, c(17.039204557769487, 14.665853784722286, 10.912861136923812, ## 7.567928838774945, 3.393524055565328, 0)) ```

gsw documentation built on July 8, 2021, 1:07 a.m.