HR: 14:55h
AN: C23B-06    [Abstracts]
TI: Sea Ice Freeboards and Snow Depths in the Arctic Based on Satellite Laser and Radar Altimetry
AU: * Skourup, H
EM: hsk@space.dtu.dk
AF: Danish National Space Center, Juliane Maries Vej 30, Copenhagen, 2100, Denmark
AU: Forsberg, R
EM: rf@space.dtu.dk
AU: Hanson, S
EM: sha@space.dtu.dk
AU: Hvidegaard, S M
EM: smh@space.dtu.dk
AU: Stenseng, L
EM: stenseng@space.dtu.dk
AB: Recent techniques make it possible to monitor the sea ice freeboards in the Arctic Ocean from satellite altimetry, and by use of models under assumption of isostatic equilibrium the freeboard can be converted into thicknesses. This is however, a crude assumption as the conversion factor depends on local sea ice and snow properties, e.g. densities and the depth of the snow cover. The main unknown factor so far is the snow depth. The laser detect the surface of the snow cover, whereas conventional radar altimetry is believed to penetrate down to the snow-ice interface, depending on the snow properties. In this study we present the methods for estimation of sea ice freeboards obtained from ICESat laser altimetry from a lowest-level technique, which on Arctic Ocean basin wide scale shows good correlation with the distribution of thick multi year sea ice extracted from QuikSCAT backscatter maps. In addition we will present the results of near coincident high-resolution airborne laser scanner measurements and radar altimetry from ENVISAT in the Fram Strait and north of Alaska to estimate the differences in freeboard heights and by that obtain an estimate of the snow depths.
DE: 0700 CRYOSPHERE (4540)
DE: 0736 Snow (1827, 1863)
DE: 0750 Sea ice (4540)
DE: 0758 Remote sensing
SC: Cryosphere [C]
MN: 2007 Fall Meeting