Dehn Ice Charts, 1953-1986 | ARC Archives Catalog
The National Snow and Ice Data Center/World Data Center for Glaciology, Boulder (NSIDC/WDC) holds a collection of charts depicting ice conditions in the seas off Alaska and western Canada coasts. Ice edge position and some ice concentration and other information are included, though the notations on the charts are often sparse and discontinuous in space and time, especially for older charts in the series.
The earliest chart is from January 1953, and the most recent is from December 1986. They range in number from about 80 to about 350 per year. A major change occurred in 1975, when the number of analyses roughly doubled. From 1975 on, Sea Ice Consultants, Inc. provided near real time analyses and forecasts. Charts from this period are extremely detailed and are believed to be the best available for Alaskan waters.