MATLAB Examples

# accumulation_interp documentation

accumulation_interp returns accumulation data, interpolated to any lat,lon point, line, or grid. This function is a plugin for the Antarctic Mapping Tools package.

This function requires Antarctic Mapping Tools.

## Contents

This function plots Arthern's tif-formatted accumulation data, which can be downloaded here. Download it, unzip it, and make sure Matlab can find the data. Then you should be able to use the accumulation_data function.

## Syntax

```vari = accumulation_interp(lati,loni)
vari = accumulation_interp(xi,yi)
vari = accumulation_interp(...,'rms')```

## Description

vari = accumulation_interp(lati,loni) linearly interpolates Arthern's accumulation rates to any geo location(s) given by lati,loni.

vari = accumulation_interp(xi,yi) accepts inputs as polar stereographic (true lat -71) x,y locations in meters.

vari = accumulation_interp(...,'rms') gives the rms error estimates.

## Examples

Interpolate to a 3 km grid over Ross Ice Shelf:

```% Make a grid: [lat,lon] = psgrid(-80,-175,1200,3); % Interpolate accumulation rates: A = accumulation_interp(lat,lon); % Plot: pcolorps(lat,lon,A) axis tight antbounds('gl','k') antbounds('coast','k') cb = colorbar; ylabel(cb,' accumulation (mm/a) ') % Put an inset map in lower left corner: mapzoomps('sw') ```

Overlay rms error contours:

```err = accumulation_interp(lat,lon,'rms'); contourps(lat,lon,err,5:15,'r') caxis([60 310]) ```

## Pairing with other datasets

If you have the Bedmap2 toolbox or any of the other surface DEM interpolation functions, it can be insightful to plot accumulation data in context of surface topography. We'll just use the hillshade effect of surface topography to provide the context. Start by getting surface elevation data, then plot everything as a surface:

```Z = bedmap2_interp(lat,lon,'surface'); % Plot: figure surfps(lat,lon,Z,A) view(2) axis tight antbounds('gl','k') antbounds('coast','k') cb = colorbar; ylabel(cb,'accumulation') % Apply hillshade: shadem(18,[225 72]) mapzoomps('sw') ```

And if you have the MEaSUREs toolbox you can add ice flow vectors:

```measuresps('velocity','color',0.5*[1 1 1]) ```

## References

If this function is useful for you, please cite the following:

Arthern, R. J., D. P. Winebrenner, and D. G. Vaughan (2006), Antarctic snow accumulation mapped using polarization of 4.3-cm wavelength microwave emission, J. Geophys. Res., 111, D06107, doi:10.1029/2004JD005667.

Greene, C. A., Gwyther, D. E., & Blankenship, D. D. (2016). Antarctic Mapping Tools for Matlab. Computers & Geosciences. doi:10.1016/j.cageo.2016.08.003

## Author Info

This function and supporting documentation were written by Chad A. Greene of the University of Texas at Austin's Institute for Geophysics (UTIG).