|What's new in 2013?
There were fewer snow and ice extremes than in 2012. Many regions and components of the Arctic environment were closer to their long-term averages, but the effects of a persistent warming trend that began over 30 years ago remain clearly evident.
The impacts of the warming climate on the physical environment during those 30 years are influencing Arctic ecosystems on the land and in the sea.
|Summer surface air temperatures were particularly low across the central Arctic Ocean, northern Canada and Greenland relative to 2007-2012 (a period of pronounced summer sea ice retreat), and were somewhat lower than the long-term average of 1981-2010.
||Minimum sea ice extent in September 2013 exceeded the record low of 2012, but was the 6th lowest since observations began in 1979 despite the relatively cool summer of 2013. The seven lowest minimum ice extents have occurred in the last seven years, 2007-2013.
||Large land mammals convey a mixed message, with muskox numbers stable/increasing since the 1970s, while many caribou and reindeer herds currently have unusually low populations for the period 1970-2013.
|Snow extent in May 2013 reached a new record low in Eurasia, while Northern Hemisphere-wide snow extent was below average for spring (April, May, June).||Arctic tundra vegetation greenness (a measure of productivity) and growing season length have continued to increase since observations began in 1982.||Changes in fish and bottom dwelling organisms include continued northward migration of species not previously seen in the Arctic.|