HR: 1330h
AN: PP52A-0947    [PDF]
TI: Bipolar Synchroneity and Latitudinal Timing of Holocene Climate Change
AU: * Meyerson, E A
EM: eric.meyerson@maine.edu
AF: Climate Change Institute, University of Maine, Orono, ME 04469 United States
AU: * Meyerson, E A
EM: eric.meyerson@maine.edu
AF: Department of Earth Sciences, University of Maine, Orono, ME 04469 United States
AU: Mayewski, P A
EM: paul.mayewski@maine.edu
AF: Climate Change Institute, University of Maine, Orono, ME 04469 United States
AU: Mayewski, P A
EM: paul.mayewski@maine.edu
AF: Department of Earth Sciences, University of Maine, Orono, ME 04469 United States
AU: Sneed, S B
EM: sharon.sneed@maine.edu
AF: Climate Change Institute, University of Maine, Orono, ME 04469 United States
AU: Sneed, S B
EM: sharon.sneed@maine.edu
AF: School of Marine Sciences, University of Maine, Orono, ME 04469 United States
AU: Kurbatov, A V
EM: akurbatov@maine.edu
AF: Climate Change Institute, University of Maine, Orono, ME 04469 United States
AU: Kreutz, K J
EM: karl.kreutz@maine.edu
AF: Climate Change Institute, University of Maine, Orono, ME 04469 United States
AU: Kreutz, K J
EM: karl.kreutz@maine.edu
AF: Department of Earth Sciences, University of Maine, Orono, ME 04469 United States
AU: Zielinski, G A
EM: gzielinski@maine.edu
AF: Climate Change Institute, University of Maine, Orono, ME 04469 United States
AU: Zielinski, G A
EM: gzielinski@maine.edu
AF: Department of Earth Sciences, University of Maine, Orono, ME 04469 United States
AU: Taylor, K C
EM: Kendrick.Taylor@dri.edu
AF: Desert Research Institute, University and Community College System of Nevada, Reno, NV 89512 United States
AU: Brook, E J
EM: brook@vancouver.wsu.edu
AF: Washington State University,, Dept of Geology and Program in Environmental Sciences, Vancouver, WA 98686 United States
AU: Steig, E J
EM: steig@ess.washington.edu
AF: Quaternary Research Center,and Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195 United States
AB: Bipolar synchroneity and latitudinal timing of Holocene climate change is investigated by comparing two precisely dated high resolution deep ice cores that provide instrumentally calibrated reconstructions of atmospheric circulation for the South Pacific region (Siple Dome (SD), West Antarctica) and the North Atlantic (GISP2). Levels of SD sea-salt (ss) Na over the most recent 1000 years are higher than those of the last 98,000 years. This is indicative of an increase in lower tropospheric marine transport to SD related to the southward migration of the Amundsen Sea Low (ASL) as a consequence of retreat of the West Antarctic Ice Sheet (WAIS) grounding-line in the Ross Sea Embayment. Although background SD ssNa concentrations are related to the WAIS grounding-line retreat, shorter-term, millennial-scale increases (rapid climate change events) are evident in the SD core chemistry. The SD ssNa record shows increases at 8100, and from 6000 to 5000, 3000 to 2500, and 750 to 0 years before present (B.P.; present defined as A.D. 2000) that similar in timing to GISP2 ssNa increases. The latter, most recent event (henceforth the modern millennial, MM) occurs during the best-dated portion of the SD and GISP2 records (dating precision of 1 to 2 percent; resolution of 2.5 years per sample) at a time when the ASL, the major source of atmospheric circulation variability at SD, is at its most southward location. The MM event encompasses the start of the classical Little Ice Age (nominally 650 years B.P. or A.D. 1350) and is first recorded in SD ssNa 150 years before GISP2 ssNa. Dust increases at SD begin at 400 years B.P. when MM-related atmospheric circulation changes extend northward to latitudes where the dominant sources of extra-Antarctic dust are located (i.e., mid-latitude Southern Hemisphere continents). The atmospheric circulation proxy records from SD and GISP2 show that the MM event propagates through the troposphere from the high-latitudes to the mid-latitudes. The SD ssNa proxy for marine tropospheric circulation during the MM event provides an example of a rapid climate change event under near-modern boundary conditions. The MM event is the most dramatic climate change event of the last 5000 years recorded in the SD, GISP2, and Taylor Dome ice cores, and it offers a precisely dated, high resolution test of the onset timing of millennial scale rapid climate change events in the modern era.
DE: 1610 Atmosphere (0315, 0325)
DE: 1620 Climate dynamics (3309)
DE: 1863 Snow and ice (1827)
DE: 3309 Climatology (1620)
DE: 3344 Paleoclimatology
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting