HR: 1340h
AN: C33A-0340    [Abstracts]
TI: A 700-Year Regional History of Greenland Ice Sheet Accumulation
AU: * Glueck, M F
EM: maryg@hwr.arizona.edu
AF: Department of Hydrology and Water Resources, University of Arizona, Harshbarger Bldg., P.O. Box 210011, Tucson, AZ 85721 United States
AU: Bales, R
EM: rbales@ucmerced.edu
AF: School of Engineering, University of California, Merced, P.O. Box 2039, Merced, CA 95344 United States
AB: Greenland Ice Sheet mass balance is a key indicator of climate variability, past and present. However, a great deal of uncertainty still exists regarding changes in mass balance at regional scales due to observational data and modeling constraints. The decade-to-century scale variability in regional accumulation was explored using a set of 21 individual site and six regional records developed for the purpose of exploring spatial differences in annual accumulation time histories across the ice sheet. The six regional records: (1) Northwest, (2) Crete area, (3) West central, (4) Southwest, (5) Central, and (6) Southeast, have been developed through statistical and time series analysis based on similarities in individual site accumulation series. Common period of record for five of the regional records is AD 1244-1984, while the remaining record spans AD 1717-1997. From the six regional records (Gaussian filtered and unfiltered), it is apparent that although there are extended periods in which the regional groups show similar accumulation trends, non-stationary regional co-variability is also quite evident. For instance, filtered records from groups 1 and 3 show similar interannual behavior throughout the record but they decouple in the late 1600's and mid-late 1700's. For 1810-1840, negative anomalies extend across the ice sheet except at groups 4-6 where positive anomalies are observed for the decade beginning about 1825. Anomalies become increasingly positive across the ice sheet again by the late 1880's. During the 1950's and early 1960's, groups 2 and 5 indicate positive anomalies while groups 1, 3, and 4 are predominantly negative. Cumulative changes in regional accumulation show a +12-m deviation from the 1245-1984 regional mean for groups 3 and 6 and an opposite 23-m deviation in group 1.
UR: http://faculty.ucmerced.edu/rbales/Greenland
DE: 3344 Paleoclimatology
DE: 3349 Polar meteorology
DE: 3309 Climatology (1620)
DE: 1863 Snow and ice (1827)
DE: 1600 GLOBAL CHANGE (New category)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting