Greenland ice-sheet surface properties observed by the Seasat-A scatterometer at enhanced resolution
Abstract For 3 months in 1978, the 14.6 GHz Seasat-A scatterometer (SASS) measured the normalized microwave-radar back-scatter coefficient of the Earth’s surface for the purpose of estimating near-surface vector winds over the ocean. SASS also made back-scatter measurements over land and ice regions...
| Published in: | Journal of Glaciology |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Cambridge University Press (CUP)
1994
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1017/s0022143000007310 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000007310 |
| Summary: | Abstract For 3 months in 1978, the 14.6 GHz Seasat-A scatterometer (SASS) measured the normalized microwave-radar back-scatter coefficient of the Earth’s surface for the purpose of estimating near-surface vector winds over the ocean. SASS also made back-scatter measurements over land and ice regions; however, the application of this data has been limited due to the low (50 km) resolution of the measurements. Using a new technique for generating 6 km enhanced-resolution SASS images of the radar back-scatter characteristics, we present a study of the 1978 condition of the Greenland ice sheet. We derive a time-series of back-scatter images spanning the period July–September 1978. These images show the extent of summer ablation along the ice-sheet periphery. Using the data and models relating firn structure and condition to radar back-scatter characteristics, we delineate and map the seasonal extent of zones which appear to correspond to dry-snow, percolation, wet-snow, and ablation facies, over virtually the entire ice sheet. The results provide a base line with which to compare current (ERS-1) and future Greenland radar maps of snow-and ice-surface conditions. |
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