R arctic polar plots

For a project I needed to create an appealing plot of the arctic, showing the location of some field sites. I’ve posted this map on twitter earlier today. Below, I’ll outline a simple routine to recreate this plot, and if need be adjust it to your liking.

First of all I downloaded an appealing background from the Blue Marble dataset as created by NASA. Geotiffs can be downloaded here or by direct download following this link. Alternatively you can download the less realistic and more summary style graphics as produced by Natural Earth.

After downloading the Blue Marble geotiff you trim the data to the lowest latitude you want to plot. Subsequently, I reproject the data to the EPSG 3995 projection (or arctic polar stereographic). All this is done using GDAL. This step could be done using rgdal, but at times this doesn’t play nice. For now I post the command line GDAL code.

UPDATE: the below command line gdal code is not necessary anymore as I call the raster library in R now which works fine in dealing with the reprojection after some fiddling.

The remaining R code ingests this background image and overlays a graticule and some labels. For this I heavily borrowed from the sp map gallery.