Executive Summary

November 23, 2011

Overview

The Arctic Report Card (www.arctic.noaa.gov/reportcard/) considers a wide range of environmental observations throughout the Arctic, and is updated annually. A major conclusion of the 2011 Report is that there are now a sufficient number of years of data to indicate a shift in the Arctic Ocean system since 2006. This shifted is characterized by the persistent decline in the thickness and summer extent of the sea ice cover, and a warmer, fresher upper ocean. As a result of increased open water area, biological productivity at the base of the marine food chain has increased and sea ice-dependent marine mammals continue to lose habitat. Increases in the greenness of tundra vegetation and permafrost temperatures are linked to warmer land temperatures in coastal regions, often adjacent to the areas of greatest sea ice retreat. A second key point in the 2011 Report is the repeated occurrence of 2010 Arctic winter wind patterns that mark a departure from the norm. These changes resulted in higher than normal temperatures in the Arctic, with record ice sheet mass loss, record low late spring snow cover in Eurasia, shorter lake ice duration, and unusually lower temperatures and snow storms in some low latitude regions. A potential indicator of recent atmospheric changes was record low ozone concentrations in March 2011. The 2011 Report Card shows that record-setting changes are occurring throughout the Arctic environmental system. Given the projection of continued global warming, it is very likely that major Arctic changes will continue in years to come, with increasing climatic, biological and social impacts.

Highlights for 2011

Sea ice and ocean observations over the past decade (2001-2011) suggest that the Arctic Ocean climate has reached a new state, with characteristics different than those observed previously. The new ocean climate has less sea ice (both thickness and summer extent) and, as a result, a warmer and fresher upper ocean. A clockwise ocean circulation regime has dominated the Arctic Ocean for at least 14 years (1997-2011), in contrast to the typical duration of a 5-8 year pattern of circulation shifts observed from 1948-1996. In the Bering Sea, aragonite undersaturation, i.e., ocean acidification, throughout the water column is causing seasonal calcium carbonate mineral suppression in some areas.

The September 2011 Arctic sea ice extent was the second lowest of the past 30 years. The five lowest September ice extents having occurred in the past five years, suggesting that a shift to a new sea ice state continues. The amount of older, thicker multiyear ice continues to decrease and both the Northern Sea Route and the Northwest Passage were ice-free in September.

Observations of the Arctic marine ecosystems provide a glimpse of what can only be described as profound and continuing changes. For example, primary production by phytoplankton in the Arctic Ocean increased ~20% between 1998 and 2009, mainly as a result of increasing open water extent and duration of the open water season. Changes in Arctic Ocean bottom communities include shifts in composition, geographical ranges, and biomass. While polar bears and walrus are experiencing negative impacts due to loss of habitat, whales now have greater access to the Northwest Passage and other northern feeding areas.

There is a direct link between increases and earlier peaks in Arctic tundra vegetation in many parts of the Arctic and increasing duration of the open water season due to decreasing summer sea ice extent. Vegetation productivity ranged from a 26% increase adjacent to the Beaufort Sea to a small decline in several areas. On the North Slope of Alaska, immediately south of the Beaufort Sea, new record high temperatures at 20 m depth were recorded at all permafrost observatories, where measurements began in the late 1970s. River discharge into the Arctic Ocean during 2010 was close to the long-term mean. Despite changes in tundra biomass, migratory barren-ground caribou appear to be within known ranges of natural variation.

In 2011 there was continued widespread warming in the Arctic, where deviations from historical air temperatures are amplified by a factor of two or more relative to lower latitudes. This phenomenon, called Arctic Amplification, is primarily a consequence of increased summer sea ice loss and northward transport of heat by the atmosphere and ocean. December 2010 to January 2011, and summer 2011, repeated the shift in wind patterns observed in December 2009 and February 2010 that resulted in relatively warm Arctic temperatures and severe cold weather in eastern North America, northern Europe and eastern Asia. Related to these shifts, the western slope of the Greenland ice sheet in particular experienced an increase in surface melting in summer 2011, amplified by albedo feedback and below-normal summer snowfall. Satellite gravity measurements show that the mass loss from the entire Greenland ice sheet during 2010-2011 was the largest annual loss in the satellite record of 2002-present. Lake ice cover duration, largely influenced by air temperature changes, was shorter by as much as 4-5 weeks in 2010-2011 compared to the 1997-2010 average in the eastern Canadian Arctic.

Acknowledgments

The Arctic Report Card reflects the work of an international team of 121 researchers in 14 countries and is based upon published and ongoing scientific research. Peer-review of the scientific content of the report card was facilitated by the Arctic Monitoring and Assessment (AMAP) Program. The Circumpolar Biodiversity Monitoring Program (CBMP), the cornerstone program of the Arctic Council's Conservation of Arctic Flora and Fauna (CAFF) Working Group, provides leadership on the biodiversity elements of the report card. The Report Card is lead by an inter-agency team from NOAA, the Cold Regions Research and Engineering Laboratory and the Office of Naval Research. Support for the Arctic Report Card is provided by the NOAA Climate Program Office through the Arctic Research Program.