HR: 17:20h
AN: C22B-06 INVITED     [PDF]
TI: Present and Past ice Sheet Mass Balance Simulations for Greenland and the Tibetan Plateau
AU: * Casal, T G
EM: tcasal@rsmas.miami.edu
AF: Center for Climatic Research & Depart. of Atmos. and ocean. sciences, Univ. of Wisc.-Madison, 1225 W. Dayton st., Madison, WI 53706 United States
AU: * Casal, T G
EM: tcasal@rsmas.miami.edu
AF: Univ. Miami, Rosentstiel School (MPO), 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AU: Kutzbach, J E
EM: jek@wisc.edu
AF: Center for Climatic Research & Depart. of Atmos. and ocean. sciences, Univ. of Wisc.-Madison, 1225 W. Dayton st., Madison, WI 53706 United States
AB: Net annual mass balance was evaluated for Greenland and the Tibetan Plateau using the meteorological forcings from the NCEP reanalysis and two GCMs (FOAM1.0 and CSM1.4) for modern climate and for different time periods extending back to the beginning of the Holocene (11,000 years ago) for the climate models. The ice sheet budget calculations, using the degree day methodology, were performed on a finer grid than the model output by interpolating monthly precipitation and surface temperature and correcting the latter to account for the GCM's smoothed topography. The computed net mass balance for Greenland in the present day is positive and it ranges between 245 to about 297 mm water equivalent (w.e.)/year for NCEP and CSM1.4 respectively. The past climate simulations show that the Greenland mass balance has become slightly more positive since the beginning of the Holocene. The Tibetan Plateau's present day area average net mass balance is negative for the three datasets (it ranges between -1160 to -1985 mm w.e./year for FOAM1.0 and CSM1.4 respectively), although the balance is positive over small regions of the plateau. The calculated past mass balance shows an increasingly less negative value for FOAM towards the present and expansion of the positive mass balance areas, mainly due to decreased snow ablation; in CSM the opposite trend occurs but changes are smaller and less systematic. The result from FOAM shows that the likelihood of ice sheets developing on the Tibetan Plateau may have increased since 11000 years ago, which is consistent some glacial records.
DE: 1827 Glaciology (1863)
SC: Cryosphere [C]
MN: 2003 Fall Meeting