Background images for cartopy plots
Cartopy is a python package for geospatial data processing that can be used to produce production quality maps. It is the supported package for this purpose and is part of our python conda distribution installed at NCI.
The cartopy package has replaced the now deprecated basemap. One of the useful functions provided by basemap that has no equivalent in the cartopy package is the ability to easily add a background "NASA Blue Marble" image.
We have downloaded three NASA blue marble products (bluemarble, city lights, explorer base map) and made them easily available to use as a background for a cartopy plot. The shut up and show me how is:
plt.figure(figsize=(24,12)) ax = plt.subplot(111, projection=ccrs.PlateCarree()) ax.background_img(name='bluemarble', resolution='high')
replace bluemarble with lights or explorer to access the different products. All are avaible in four different resolutions: low, medium, high and extrahigh (aliases for 1.0deg, 0.5deg, 0.25deg and 0.1deg).
Examples of each plot
Explorer Base Map:
Blue Marble as a background image with SST data in a near side cartopy projection
The code to generate the picture above is available as a jupyter notebook.