This graphic may be reproduced in any form for educational or non-profit purposes without special permission from GRID-Arendal, provided acknowledgement of the source is made. GRID-Arendal would appreciate receiving a copy of any publication that features this graphic.
No use of this graphic may be made for resale or any other commercial purpose whatsoever without prior permission in writing from GRID-Arendal. Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed to firstname.lastname@example.org.
For any form of publication, please include the link to this page and give GRID-Arendal and the cartographer/designer credit (in this case Hugo Ahlenius, UNEP/GRID-Arendal)
Armstrong, R.L. and Brodzik, M.J. (2005). Northern Hemisphere EASE-Grid weekly snow cover and sea ice extent version 3. (Digital media). National Snow and Ice Data Center, Boulder Armstrong, R.L., Brodzik, M.J., Knowles, K. and Savoie, M. (2005). Global monthly EASE-Grid snow water equivalent climatology. (Digital media). National Snow and Ice Data Center, Boulder Brown, J., Ferrians Jr., O.J., Heginbottom, J.A. and Melnikov, E.S. (1998 revised February 2001). Circum-Arctic map of permafrost and ground-ice conditions. (Digital media). National Snow and Ice Data Center/World Data Center for Glaciology, Boulder NGA (2000). Vector Map Level 0. National Geospatial-Intelligence Agency. http://geoengine.nima.mil/ftpdir/archive/vpf_ data/v0soa.tar.gz [Accessed 1 September 2006] Stroeve, J. and Meier, W. (1999, updated 2005). Sea Ice Trends and Climatologies from SMMR and SSM/I. National Snow and Ice Data Center. http://nsidc.org/data/smmr_ssmi_ ancillary/monthly_means.html [Accessed 20 April 2007]