HR: 10:50h
AN: PP52A-03 INVITED    [Abstracts]
TI: Ice Core Evidence for Amplification of the Recent Warming at High Elevations in the Tropics and the Likely Regional Impacts
AU: * Thompson, L G
EM: thompson.3@osu.edu
AF: The Ohio State University Byrd Polar Research Center, 1090 Carmack Road, Columbus, OH 43210, United States
AU: Mosley-Thompson, E S
EM: thompson.4@osu.edu
AF: The Ohio State University Byrd Polar Research Center, 1090 Carmack Road, Columbus, OH 43210, United States
AU: Davis, M E
EM: davis.3@osu.edu
AF: The Ohio State University Byrd Polar Research Center, 1090 Carmack Road, Columbus, OH 43210, United States
AU: Urmann, D
EM: urmann.1@osu.edu
AF: The Ohio State University Byrd Polar Research Center, 1090 Carmack Road, Columbus, OH 43210, United States
AU: Buffen, A
EM: buffen.1@osu.edu
AF: The Ohio State University Byrd Polar Research Center, 1090 Carmack Road, Columbus, OH 43210, United States
AB: IPCC (2007) models predict an enhancement of warming at higher altitudes throughout the tropics where temperatures may warm twice as much as the globally-averaged increase of 3°C predicted for sea level by 2100 AD. Ice core data collected over the last thirty years from low-latitude, high-elevation glaciers, along with continuous monitoring of selected sites, document this amplification and suggest an imminent demise of many of these ice fields. A new, annually resolved climatic and environmental record from the Quelccaya ice cap (5670 m asl) in Peru extends back to 315 AD. A new record from the higher, colder and drier Coropuna ice field (6450 m asl), 350 km southwest of Quelccaya and only 70 km from the Pacific Ocean, provides a much longer, albeit lower resolution, ~16,000 year history. El Niño-Southern Oscillation variations are recorded at both sites and document millennial scale variability. A series of ice cores drilled across High Asia provides climatic and environmental histories that also document the amplification of air temperature at high elevations. Regional impacts of this warming may already be underway. Observations in 2006 on Naimona'nyi (6100 m asl, also known as Gurla Mandata), located near the headwaters of the Ganges and Indus Rivers, indicate that under current climate conditions this ice field is not gaining mass. Ice cores from the Dasuopu glacier (7200 m asl) in the central Himalaya provide a high-resolution record of fluctuations in the intensity of the South Asian Monsoon. Reductions in monsoon intensity are recorded by insoluble dust and chloride concentrations. The deeper, older sections of the Dasuopu record reveal numerous arid periods, but none were longer and more intense than the 1790 to 1796 A.D. drought. This event is also prominent in the soluble aerosol records from the Quelccaya and Coropuna cores on the eastern side of the Pacific Basin, suggesting decadal-scale teleconnections between these regions. The similarities and differences among these high-resolution paleoclimate records for the last 1500 years will be discussed. The δ¹⁸O data from the high accumulation ice core sites around the Pacific Basin are compared with Niño 4 sea surface temperatures (SSTs) since the 1890s and appear to capture decadal-scale variations. Thus, they may offer the potential to extend the central tropical Pacific SST record beyond the instrumental period.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1621 Cryospheric change (0776)
DE: 1630 Impacts of global change (1225)
DE: 1637 Regional climate change
DE: 4932 Ice cores (0724)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting