Sensitivity of Northern Hemispheric continental ice sheets to tropical SST during deglaciation
نویسندگان
چکیده
[1] A thermomechanical ice sheet model (ISM) is used to investigate the sensitivity of the Laurentide and Fennoscandian ice sheets to tropical sea surface temperature (SST) perturbations during deglaciation. The ISM is driven by surface temperature and precipitation fields from three different atmospheric general circulation models (AGCMs). For each AGCM, the responses in temperature and precipitation over the ice sheets nearly compensate, such that ice sheet mass balance is not strongly sensitive to tropical SST boundary conditions. It was also found that there is significant variation in the response of the ISM to the different AGCM output fields.
منابع مشابه
A Tropical Mechanism for Northern Hemisphere Deglaciation
We investigate the role of the tropics in the melting and reforming of the Laurentide ice sheet on glacial timescales using an atmospheric general circulation model. It is found that warming of tropical sea surface temperatures (SST) from glacial boundary conditions, as observed at the end of glacial periods [Bard et al., 1997, Lea et al., 2000, Nurnberg et al., 2000], causes a large increase i...
متن کاملThe Influence of Continental Ice Sheets on the Climate of an Ice Age
The climate influence of the land ice that existed 18,000 years before present (18K B.P.) is investigated by use of a general circulation model of the atmosphere coupled with a static mixed layer ocean. Simulated climates are obtained from two versions of the model: one with the land ice distribution of the present and the other with that of 18K B.P. In the northern hemisphere the tropospheric ...
متن کاملGlacial-Interglacial Atmospheric CO2 Change —The Glacial Burial Hypothesis
Organic carbon buried under the great ice sheets of the Northern Hemisphere is suggested to be the missing link in the atmospheric CO2 change over the glacial-interglacial cycles. At glaciation, the advancement of continental ice sheets buries vegetation and soil carbon accumulated during warmer periods. At deglaciation, this burial carbon is released back into the atmosphere. In a simulation o...
متن کاملEarly deglaciation in the tropical Andes.
Tropical Andes The record of ancient glaciers is the principal source of information on high-altitude paleoclimate in the tropics, but the age of late Pleistocene glaciation throughout the tropics is poorly constrained, which complicates estimating past climate from glacial records. Seltzer et al. (1) established that maximum late Pleistocene glaciation in the tropical Andes was broadly synchro...
متن کاملThe Last Glacial Maximum.
We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pac...
متن کامل