HR: 0800h
AN: C51B-0395    [Abstracts]
TI: Effect of firn depth and density variations on elevation changes in Antarctica reveals opposing ice sheet mass balance pattern
AU: * Helsen, M M
EM: helsen@phys.uu.nl
AF: Institute for Marine and Atmospheric research Utrecht Utrecht University, PO Box 80000, Utrecht, 3508 TA, Netherlands
AU: van den Broeke, M R
EM: M.R.vandenBroeke@phys.uu.nl
AF: Institute for Marine and Atmospheric research Utrecht Utrecht University, PO Box 80000, Utrecht, 3508 TA, Netherlands
AU: van de Wal, R S
EM: r.s.w.vandewal@phys.uu.nl
AF: Institute for Marine and Atmospheric research Utrecht Utrecht University, PO Box 80000, Utrecht, 3508 TA, Netherlands
AU: van de Berg, W
EM: W.J.vandeBerg@phys.uu.nl
AF: Institute for Marine and Atmospheric research Utrecht Utrecht University, PO Box 80000, Utrecht, 3508 TA, Netherlands
AU: van Meijgaard, E
EM: vanmeijg@knmi.nl
AF: Royal Netherlands Meteorological Institute, PO Box 201, De Bilt, 3730 AE, Netherlands
AU: Davis, C H
EM: DavisCH@missouri.edu
AF: Department of Electrical and Computer Engineering University of Missouri-Columbia, 323 Engineering Bldg. West, Columbia, MO 65211, United States
AU: Li, Y
EM: LiYo@missouri.edu
AF: Department of Electrical and Computer Engineering University of Missouri-Columbia, 323 Engineering Bldg. West, Columbia, MO 65211, United States
AU: Kaczmarska, M
EM: Marzena@npolar.no
AF: Norwegian Polar Institute Polar Environmental Centre, Hjalmar Johansens gate 14, Tromso, N-9296, Norway
AU: Goodwin, I
EM: Ian.Goodwin@newcastle.edu.au
AF: School of Environmental and Life Sciences University of Newcastle, Geology Building Room GG15 University Drive, Callaghan, NSW 2308, Australia
AU: Kaspari, S
EM: susan.kaspari@maine.edu
AF: Climate Change Institute University of Maine, 303 Bryand Global Sciences Center, Orono, ME 04469, United States
AB: Satellite radar altimetry is a valuable tool to monitor ice sheet elevation change (dH/dt). Before dH/dt observations can be translated into long-term mass changes, corrections must be made for short-term variability in firn densification rate and accumulation. We calculated this contribution for the observational period of ERS-2 (1995- 2003), using 6-hourly output of a regional atmospheric model (1980-2004) to drive a time-dependent firn densification model. The results show that interannual anomalies in snow accumulation can cause ice sheet elevation changes comparable to those observed by satellite radar altimetry. Taking these firn depth fluctuations into account, the satellite-derived elevation change reveals a pattern of persistent large mass losses in the Amundsen Sea sector in West Antarctica, but also shows that the East Antarctic ice sheet grows, resulting in a net mass increase of 19 Gt/yr for the grounded ice sheet, equivalent to a sea level lowering of 0.05 mm/yr.
DE: 0726 Ice sheets
DE: 0762 Mass balance (1218, 1223)
DE: 0798 Modeling
DE: 1218 Mass balance (0762, 1223, 1631, 1836, 1843, 3010, 3322, 4532)
DE: 1223 Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions (0762, 1218, 3319, 4550)
SC: Cryosphere [C]
MN: 2007 Fall Meeting