HR: 0800h
AN: PP51A-0187    [Abstracts]
TI: The Holocene Record of the Arctic Oscillation and a Possible Link to Solar Variability
AU: Rand, J
EM: jrand@odu.edu
AF: Dept. of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, Oceanography and Physical Sciences Building 4600 Elkhorn Avenue, Norfolk, VA 23529-0276, United States
AU: * Darby, D A
EM: ddarby@odu.edu
AF: Dept. of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, Oceanography and Physical Sciences Building 4600 Elkhorn Avenue, Norfolk, VA 23529-0276, United States
AU: Ortiz, J
EM: jortiz@kent.edu
AF: Department of Geology, Kent State University, 221 McGilvrey Hall, Lincoln and Summit Streets, Kent, OH 44242, United States
AU: Cook, M Y
EM: meacook@ucsc.edu
AF: Physical and Biological Sciences Department, UC at Santa Cruz, Division of Physical and Biological Sciences, Nat Sci II Annex, University of California at Santa Cruz, Santa Cruz, CA 95064, United States
AU: Keigwin, L
EM: lkeigwin@whoi.edu
AF: Woods Hole Oceanographic Institution, McLean 207A, MS#8, Woods Hole, MA 02543, United States
AB: Detailed Fe grain provenance for a 19.9 meter long piston core (HLY02-JPC16) with about 17.5 m of Holocene sediment provides a sub-century scale resolution of the Arctic Oscillation (AO). The presence of Fe grains matched to Russian shelves fluctuates throughout this core, located 125 km north of Alaska in 1300 m water depth. High amounts of these Fe grains indicate a strong positive AO. While century scale fluctuations occur in the influx of Russian ice-rafted grains at this core site, a significant periodicity of about 1500 years exists that is similar to that of Be-10 in the Greenland ice cores. This begs the question as to how the AO might be linked to solar variations, especially such weak ones. The sources of sea ice rafting throughout the Holocene are compared to Modern sea ice samples and there is generally a good match. There is much greater heterogeneity in sources based on Fe grain provenance than other techniques for sourcing sea ice today. While the Laptev Sea is certainly an important sea ice entrainment area, it is by no means the only one and not even the most important over the long term. This distinction lies with northern Canadian sources, especially the Queen Elizabeth Islands facing the Arctic Ocean. The AO plays a major role in mixing sea ice from Russian and North American sources, especially during ++AO events. At these times, not only does the Trans Polar Drift swing closer to North America introducing sea ice from the Russian shelves such as the Laptev Sea to the Beaufort Gyre (BG), but it also aids in dragging some of the BG ice toward Fram Strait. This BG ice is a mix of North American and Russian ice and thus it is not surprising to find sediment from both sources in ice along the drift path of this ice moving toward Fram Strait.
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1637 Regional climate change
DE: 3022 Marine sediments: processes and transport
DE: 4558 Sediment transport (1862)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting