HR: 1340h
AN: PP23A-1069    [Abstracts]
TI: Central Asian Glacier Sensitivity and Regional Climate: Past and Present
AU: * Rupper, S
EM: srupper@byu.edu
AF: Dept of Geological Sciences Brigham Young University, S389 ESC, Provo, Ut 84602,
AU: Roe, G
EM: gerard@ess.washington.edu
AF: Earth and Space Sciences University of Washington, Box 351310, Seattle, Wa 98043,
AU: Gillespie, A
EM: alan@rad.ess.washington.edu
AF: Earth and Space Sciences University of Washington, Box 351310, Seattle, Wa 98043,
AB: A surface energy- and mass-balance model that captures the interactions between glaciers and climate on regional-scales is presented. The model is applied to Central Asia because of the diverse climate regimes and unusual glacier history. It is used to understand the sensitivity of equilibrium line altitudes (ELAs) to modern interannual climate variability, and to reconcile patterns of ELA changes with climate changes during the early Holocene and Last Glacial Maximum (LGM) in Central Asia. Patterns in the present day climate give rise to patterns in the dominant ablation mechanisms at the ELA. In turn the patterns in ablation give rise to patterns in glacier sensitivity to climate changes. In particular, ELAs in melt-dominated regions are most sensitive to interannual variability in temperature. ELAs in sublimation-dominated regions are most sensitive to interannual variability in precipitation. The patterns of glacier advance and retreat during the early Holocene and LGM, in the melt-dominated regions, are both due to the patterns in temperature change. Glaciers in sublimation-dominated regions are highlighted as being acutely sensitive to even small changes in numerous atmospheric variables. For present day, Holocene, and LGM, changes in clouds are important in all regions through their influence on the shortwave and longwave radiative fluxes, which dominate the surface energy balance at the ELA. This work highlights the importance of a systematic analysis of the sensitivity of glaciers to changes in climate.
DE: 0720 Glaciers
DE: 0762 Mass balance (1218, 1223)
DE: 1637 Regional climate change
DE: 3344 Paleoclimatology (0473, 4900)
DE: 9320 Asia
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting