Probability of Sea Ice Extent: Between Eastern Greenland and Iceland 1821-1956

Our data set includes nine probability maps of sea ice extent, available in .jpeg and shapfiles. They were created from historical maps of sea ice extent off Iceland dating back to 1877 compiled by Koch (1945) that we digitized. We use these maps in combination with sea ice charts from the Danish Meteorological Institute (DMI) and Koch's sea ice index from 1820 to 1939 to provide spatial maps of estimated sea ice extent between Iceland and Greenland back to 1821.
The probability maps should be used in combination with the table: Summary of Koch's Index Years, in order to know which years fall under which category.

本数据集包含九幅海冰范围概率图，格式为JPEG与形状文件（shapefile）。这些概率图由我们数字化整理Koch（1945）编制的、可追溯至1877年的冰岛周边海冰范围历史地图生成。我们将这些地图与丹麦气象研究所（Danish Meteorological Institute, DMI）提供的海冰冰情图，以及Koch在1820年至1939年间编制的海冰指数相结合，从而生成可追溯至1821年的冰岛与格陵兰之间海域的估算海冰范围空间分布图。
使用该海冰范围概率图时，需配合《Koch指数年份汇总表》（Summary of Koch's Index Years）进行对照，以明确各年份对应的分类类别。