Farrell, S.L.;
(2006)
Satellite laser altimetry over sea ice.
Doctoral thesis , University of London.
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Abstract
The Arctic region plays an important role in the global climate system through various feedbacks, involving surface albedo, oceanic deep-water formation, and sea surface salinity, which can amplify climate variability and change. We investigate the exploitation of data collected by the first Earth-orbiting laser altimeter carried onboard ICESat over the sea-ice covered regions of the Arctic Ocean. We extract parameters associated with the study of the polar climate system including the time-varying component of sea surface topography and sea ice freeboard. We assess an existing method for the retrieval of Arctic sea surface height from ICESat data. We present an alternative method for sea surface height retrieval, based on surface reflectivity and analysis of parameters associated with the shape of the received echo. This method aims to discriminate echoes originating over leads or thin ice. We provide the first maps of Arctic sea surface height as derived from ICESat. We examine the accuracy of our results through comparisons with independent sea surface height estimates derived from ENVISAT radar altimetry. We demonstrate the use of sea surface height data for oceanographic and geodetic applications in the Arctic Ocean. We derive an ICESat mean sea surface which, when combined with the recently developed Arctic hybrid geoid model, can be used to analyse mean dynamic ocean topography. In addition we investigate the use of ICESat sea surface height measurements to map marine gravity anomalies up to the limit of coverage at 86 N. By combining ICESat surface elevation measurements with sea surface height estimates, we derive sea ice freeboard throughout the Arctic up to 86 N. We compare our results to coincident estimates of sea ice freeboard from ENVISAT. Finally, we explore the feasibility of combining satellite laser and radar altimetric measurements of sea ice freeboard to measure the depth of snow loading on sea ice.
| Type: | Thesis (Doctoral) |
|---|---|
| Title: | Satellite laser altimetry over sea ice. |
| Identifier: | PQ ETD:592799 |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Thesis digitised by Proquest |
| UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/1445477 |
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