HR: 1340h
AN: C13A-0266    [Abstracts]
TI: Trends in Arctic and Antarctic Melt Season Parameters From Reanalysis
AU: * Atkinson, D E
EM: datkinson@iarc.uaf.edu
AF: University of Alaska Fairbanks/International Arctic Research Center, 930 Koyukuk Drive, Fairbanks, AK 99775 United States
AB: Melt season is an important period in the cryoshpere. Its timing, duration, and intensity guide the response of many natural processes and system states, including ecological, hydrological, ground-thermal, glaciological, sea-ice, and snow cover. Capturing an overview of spatial-temporal patterns in melt-season parameters contributes to understanding process and state response. Trends for several melt-season parameters have been calculated from NCEP/NCAR reanalysis data for both hemispheres, including: melt season start and end dates, melt season length, and annual melting degree-day (MDD) totals. Results from the Arctic indicate simple linear trends in MDD as large as +/- 20 days/year, however it is unlikely that such rates of change have been uniformly maintained over a 50-year period. This suggests more complex temporal dynamics, similar to that exhibited by northern hemisphere temperature trends, such that trend periods should be further broken down and greater analysis performed. In terms of specific years, in certain regions of the Arctic the difference between two years can be very large, on the order of hundreds of MDD. This level of interannual variation can be of the same magnitude as MDD seasonal totals, and suggests large interannual cryospheric response to thermal forcing that should be taken into consideration when studying physical response of a cryospheric system. A subset of these results are presented.
DE: 9315 Arctic region
DE: 1620 Climate dynamics (3309)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting