The changing Arctic Sea ice cover : regional and seasonal aspects

As global climate changes are becoming increasingly evident, increasing air temperatures,\nmelting glaciers, rising sea levels, and decreasing biodiversity is observed at increasing rates\nworldwide. The Arctic sea ice cover has has become a key indicator of the ongoing global\nclimate change through its substantial decline in both extent and thickness.\nIn this study we show how the observed regression of the Northern Hemisphere sea ice is\ndistributed over different regions of the Arctic Ocean and adjacent seas. We further provide\nan evaluation of to what extent the regions are re\necting changes during summer or winter\nseasons, exemplified by the months of September and March. We also relate the changes to\nobserved atmospheric and oceanographic conditions. Data from passive microwave satellite\nmeasurements are used to investigate regional and seasonal time series of ice extent.\nAll regions except one show a decreasing trend throughout the data record. It is found that\nsix of twelve regions has seen an accelerated decline during the last decade. This is either\ncaused by an increasingly smaller summer minimum, or by a prolongation of the regional\nsummer season.\nIt is further found that summer melting is initiated by atmospheric heat in the areas where\nthe recession of ice extent most prominent. The process of freezing during winter is found\nto be particularly sensitive to the oceanic temperatures in the regions receiving currents of\nwarm Atlantic Water.