Using this graphic and referring to it is encouraged, and please use it in presentations, web pages, newspapers, blogs and reports.
For any form of publication, please include the link to this page and give the cartographer/designer credit (in this case Hugo Ahlenius, UNEP/GRID-Arendal)
NASA. 2007. NASA Surface meteorology and Solar Energy: Global Data, release 5.1 - Insolation on horizontal surface (1983-1993). http://eosweb.larc.nasa.gov/cgi-bin/sse/sse.cgi?+s01 (Accessed July 14th 2007)