HR: 0800h
AN: H31C-06    [Abstracts]
TI: Arctic sea ice Freeboard Heights From ICESat Laser Altimetry
AU: * Renganathan, V
EM: vrengana@ucalgary.ca
AF: University of Calgary,, Dept of Geomatics Engineering, 2500 University Drive NW,, Calgary, AB T2N1N4, Canada
AU: Braun, A
EM: braun@ucalgary.ca
AF: University of Calgary,, Dept of Geomatics Engineering, 2500 University Drive NW,, Calgary, AB T2N1N4, Canada
AU: Skourup, H
EM: hsk@space.dtu.dk
AF: Technical University of Denmark,, National Space Institute Geodynamics, Juliane Maries Vej 30,, Copenhagen, DK-2100, Denmark
AU: Forsberg, R
EM: rf@space.dtu.dk
AF: Technical University of Denmark,, National Space Institute Geodynamics, Juliane Maries Vej 30,, Copenhagen, DK-2100, Denmark
AB: Arctic sea ice extent has been decreasing at a rate of about 10% per decade, since the earliest satellite observations in 1979. This decline is mainly attributed to climate change and variability. The effect of climate change is more pronounced in the Arctic because of the ice-albedo feedback effect which accelerates the melting process. In order to understand the changing Arctic sea ice cover, the change in sea ice volume must be known (both extent and thickness). Sea ice thickness is an important parameter that moderates the heat exchange between the ocean and the atmosphere which affects the Earth's climate. Despite about 200 years of research and observations in the Arctic, detailed observations at large-spatial scales and long continuous time-series are not available. In this study, satellite laser altimetry data from ICESat (NASA's Ice, Cloud, and Elevation Satellite) have been used to estimate Arctic sea ice freeboard heights based on the models of geoid (EIGEN-GL04), ocean tides (AOTIM-5), and mean dynamic topography. Sea ice freeboard can be eventually converted into thickness, if the physical properties of the ice pack are known using hydrostatic equilibrium assumptions. Current limitations in this method are the lack of information on the depth of the overlying snow layer and the uncertainties in the oceanographic models. Sea ice freeboard results from ICESat for mission phases from 2003 to 2008 will be discussed.
DE: 4207 Arctic and Antarctic oceanography (9310, 9315)
SC: Hydrology [H]
MN: 2009 Joint Assembly