HR: 0800h
AN: C11B-0418    [Abstracts]
TI: Arctic sea ice Freeboard From ICESat and Envisat Altimetry
AU: * Farrell, S L
EM: Sinead.Farrell@noaa.gov
AF: NOAA Laboratory for Satellite Altimetry, 1335 East-West Highway SSMC1 E/RA31 Rm5315, Silver Spring, MD 20910, United States
AU: Laxon, S W
EM: swl@cpom.ucl.ac.uk
AF: Centre for Polar Observation and Modelling, University College London Pearson Building Gower Street, London, WC1E 6BT, United Kingdom
AU: Ridout, A L
EM: alr@cpom.ucl.ac.uk
AF: Centre for Polar Observation and Modelling, University College London Pearson Building Gower Street, London, WC1E 6BT, United Kingdom
AU: Kwok, R
EM: ron.kwok@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology 4800 Oak Grove Dr., Pasadena, CA 91109, United States
AU: McAdoo, D C
EM: Dave.McAdoo@noaa.gov
AF: NOAA Laboratory for Satellite Altimetry, 1335 East-West Highway SSMC1 E/RA31 Rm5315, Silver Spring, MD 20910, United States
AB: Knowledge of sea ice thickness, in combination with extent, is essential for determining the variability of sea ice volume and mass flux. Although the decreasing extent of sea ice cover in the Arctic Ocean has been well documented, any similar trends in ice thickness remain unclear. Recent studies have demonstrated the use of satellite radar altimeter data to estimate sea ice freeboard, and derive sea ice thickness, over basin scales. Using the latest data releases, which have benefited from improved ground processing and correction schemes, we present an analysis which compares satellite altimeter data gathered by the Geoscience Laser Altimeter System (GLAS) and the RA-2 instruments, flown onboard the ICESat and Envisat satellites respectively. Sea surface elevation is required as a reference to estimate sea ice freeboard from altimetric elevation measurements. Due to the complexities involved in identifying open water and leads in ICESat data over sea ice, a number of techniques exist to estimate sea surface elevation. We evaluate several of these techniques via comparisons with complimentary RA-2 sea surface elevation estimates. Also, we present freeboard estimates from both ICESat and Envisat. Comparisons of coincident laser and radar freeboard data offer the potential to retrieve snow accumulation on sea ice, and thereby to derive more precise thicknesses from freeboard estimates. We analyse seasonal and inter-annual differences in the freeboard signal and present snow depth estimates.
DE: 0700 CRYOSPHERE (4540)
DE: 0750 Sea ice (4540)
DE: 0758 Remote sensing
DE: 9315 Arctic region (0718, 4207)
SC: Cryosphere [C]
MN: 2007 Fall Meeting