HR: 11:05h
AN: PP42B-04    [Abstracts]
TI: The Holocene Thermal Maximum in the Arctic
AU: * MacDonald, G M
EM: macdonal@geog.ucla.edu
AF: Department of Geography, UCLA, Los Angeles, CA 90095-1524 United States
AU: Kaufman, D S
EM: darrell.kaufman@nau.edu
AF: Department of Geology, Northern Arizona University, Flagstaff, AZ 86011-4099 United States
AU: Duval, M
EM: mduvall@bates.edu
AF: PARCS Data Office, Geology Department Bates College, Lewsiton, ME 04240-6028 United States
AU: Kremenetski, K
EM: costya@geog.ucla.edu
AF: Department of Geography, UCLA, Los Angeles, CA 90095-1524 United States
AB: Through the support of the Paleoenvironmental Arctic Sciences (PARCS) program sponsored by the National Science Foundation two working groups of over 50 scientists have been synthesizing data from more than 160 terrestrial, ice-core and marine records from the Arctic. The aim of the synthesis is to provide a unified picture of the magnitude of the Holocene Thermal Maximum (HTM) and the spatiotemporal characteristics of the HTM across the broader Arctic region. Work on the western Arctic sector (0 - 180 W) has been completed and is published (Kauffman et al. 2004. Quaternary Science Reviews 23: 529 - 560). That synthesis suggests that the HTM temperatures were on average 1.6 C warmer than average 20th century temperatures. The warming was highly time-transgressive. The thermal response to the early Holocene precession-driven summer insolation maximum was concentrated in northwest North America where the HTM is apparent 12 - 9 ka (thousands of calendar years ago), while cool conditions persisted in the northeast with the HTM not apparent in Quebec and Labrador until the mid to late Holocene. The delayed warming in central and eastern Canada may be linked to the residual Laurentide Ice Sheet and thermal asymmetry caused by atmospheric circulation patterns. Our preliminary synthesis suggests that the magnitude of HTM warming was often 2.0 C or greater. In addition, there is far less dramatic regional asynchrony than in the western sector. In general, HTM conditions are apparent between approximately 10 and 4 ka in the eastern Arctic with a slighter later initiation in some areas such as northern Fennoscandia.
UR: http://www.ncdc.noaa.gov/paleo/parcs/
DE: 3344 Paleoclimatology (0473, 4900)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005