HR: 16:00h
AN: GC44A-01    [Abstracts]
TI: Arctic Change Detection: Multiple Observations and Recent Explanations
AU: Soreide, N N
EM: nancy.n.soreide@noaa.gov
AF: NOAA/Pacific Marine Environmental Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115 United States
AU: * Overland, J E
EM: James.E.Overland@noaa.gov
AF: NOAA/Pacific Marine Environmental Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115 United States
AU: Calder, J
EM: John.Calder@noaa.gov
AF: NOAA Arctic Research Office, 1315 East West Highway, Room 11362, Silver Spring, MD 20910 United States
AB: The recently released Arctic Climate Impact Assessment (ACIA) Report documents Arctic-wide changes and impacts; it provides a long-term perspective for peoples, governments and scientists in coping with these changes. Further, investigation of the last three decades of multivariate biophysical data sets(climate, land and marine ecosystems, cryosphere) and century-long weather records, show two main types of Arctic variability. These are: 1) long-term trends as represented by loss of sea-ice and tundra area and their biological response, and 2) decadal variability in atmospheric forcing and its direct impacts. Three main conclusions are possible: * Temperature anomalies in the last 15 years are unique in the Arctic instrumental record (1880-2003). Historically, there were regional/decadal warm events during winter and spring in the 1930s to 1950s, but meteorological analysis shows that these surface air temperature anomalies are the result of intrinsic variability in regional flow patterns, as contrasted with the Arctic-wide Arctic Oscillation (AO) influence of the 1990s. * These changes are primarily driven by changes in atmospheric circulation, and thus are subject to north/south gradients in hemispheric radiative forcing from volcanic aerosols, insolation cycles and CO2 increase. These north/south differences drive temperature advection in the trough-ridge structure of the AO. This conclusion is based primarily on model results and impacts from volcanos. * Change is likely to be irreversible over at least the next decade. In the previous five years, many ecosystems, such as the Bering Sea and east Greenland, are showing more year-to-year persistence, despite considerable variability in the AO and other climate indices. We hypothesize that the changes occurring in the Arctic are beginning to be significant enough to make the Arctic less sensitive to cold swings in atmospheric variability, although direct mechanisms are unclear. A next step in the post-ACIA period is a comprehensive Arctic Change Detection product which builds upon the ACIA report with regularly updated information. Credibility is based on multiple lines of evidence and cooperation of scientists. The Arctic Change Detection project provides a near-realtime suite of indicators, their potential impacts, recent events, news items, and scientific publications, in an understandable format at www.arctic.noaa.gov. This website makes information about the current status of the Arctic available to a wide audience.
UR: http://www.arctic.noaa.gov
DE: 9315 Arctic region
DE: 3349 Polar meteorology
DE: 1620 Climate dynamics (3309)
DE: 1630 Impact phenomena
SC: Global Climate Change [GC]
MN: 2004 AGU Fall Meeting