HR: 14:40h
AN: OS33D-05    [Abstracts]
TI: Assessing the Likelihood of Human-Induced-Greenhouse Changes in the Atlantic Thermohaline Circulation and Climate
AU: * Schlesinger, M
EM: schlesin@atmos.uiuc.edu
AF: University of Illinois @ Urbana-Champaign, Department of Atmospheric Sciences 105 S. Gregory St., Urbana, IL 61801
AB: We have performed several 'hosing' simulations with our coupled atmosphere-ocean general circulation model wherein we have purposefully added freshwater onto the North Atlantic Ocean between 50°N and 70°N to slowdown and collapse the Atlantic Thermohaline Circulation (ATHC). We have found that there is large uncertainty in the future behavior of the ATHC due to uncertainty in how much transport there is by the non-THC motion relative to that by the ATHC, how much fresh water is added to the North Atlantic per degree of global warming, and the climate sensitivity - the global warming for a doubling of the pre-industrial CO2 concentration. One way to reduce this uncertainty is to simulate past slowdown/collapse of the ATHC with the AOGCMs and compare their simulated changes in the ATHC and global climate with paleoclimate reconstructions thereof. The presenter has proposed to the Paleoclimate Modeling Intercomparison Project II (PMIIP) and Worldwide Universities Network (WUN) Arctic Climates & Environments initiative (ACE) that a systematic program be initiated to simulate the change in ATHC and global climate during the Younger Dryas, 13,000 years ago (ka), and the '8.2 ka event', both of which were likely due to the addition of freshwater to the North Atlantic Ocean, and both of which caused cooling in Greenland, the North Atlantic and Europe. This proposal has been accepted by PMIIP and WUN-ACE. Fifteen AOGCM groups have agreed to perform hosing simulations for one or both of the YD and 8.2 ka changes in ATHC and climate.
DE: 1635 Oceans (1616, 3305, 4215, 4513)
DE: 4263 Ocean predictability and prediction (3238)
DE: 4500 OCEANOGRAPHY: PHYSICAL
SC: Ocean Sciences [OS]
MN: Fall Meeting 2005