HR: 0800h
AN: C11A-0080    [Abstracts]
TI: Increased rates of surface elevation change driven by the surface temperature (1982-2006) over the Greenland Ice Sheet
AU: * Li, J
EM: Jun.Li@nasa.gov
AF: SGT Inc., Code 614.1, NASA Goddard Space Flight Center, Greenbelt, MD 20771,
AU: Zwally, H J
AF: Cryospheric Sciences Branch, NASA Goddard Space Flight Center, Greenbelt, MD 20771,
AU: Comiso, J C
AF: Cryospheric Sciences Branch, NASA Goddard Space Flight Center, Greenbelt, MD 20771,
AB: The surface elevation change due to the changes in firn densification rate is an important component among the total changes as observed from the satellite altimetry in the mass-balance studies. In particular, the elevation change caused by the temperature variations alone does not involve any ice sheet mass exchange. This part of the change must be separated from the total changes as a correction for the accurate mass balance estimations. In this study, we use a time-dependent firn densification model driven by the continuous monthly surface air temperature (1981-2006) from AVHRR over Greenland to derive the corresponding surface elevation change over the accumulation region (> ELA) of the ice sheet. The model is characterized by the higher temperature sensitivity according to the grain growth and ice deformation rates, with the consideration of the melt effect. The results show that the continuous surface warming during the last two decades has caused the strong decrease of the surface elevation at the average rate of 7 cm a-1 (2003-2006) in comparison with 1 cm year-1 over the last decade (1992-2002).
DE: 0700 CRYOSPHERE (4540)
DE: 0736 Snow (1827, 1863)
DE: 0776 Glaciology (1621, 1827, 1863)
DE: 0798 Modeling
SC: Cryosphere [C]
MN: 2007 Fall Meeting