A ground-based radar backscatter investigation in the percolation zone of the Greenland ice sheet
Satellite radar altimeters and scatterometers deployed over ice sheets experience backscatter from the surface and from within the snowpack, termed surface and volume backscatter respectively. In order to assess the errors in satellite altimeter measurements it is vital to know where the return is o...
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ftnerc:oai:nora.nerc.ac.uk:969 2023-05-15T15:47:39+02:00 A ground-based radar backscatter investigation in the percolation zone of the Greenland ice sheet Scott, Julian B.T. Mair, Doug Nienow, Pete Parry, Victoria Morris, Elizabeth 2006 http://nora.nerc.ac.uk/id/eprint/969/ https://doi.org/10.1016/j.rse.2006.05.009 unknown Elsevier Scott, Julian B.T.; Mair, Doug; Nienow, Pete; Parry, Victoria; Morris, Elizabeth. 2006 A ground-based radar backscatter investigation in the percolation zone of the Greenland ice sheet. Remote Sensing of Environment, 104 (4). 361-373. https://doi.org/10.1016/j.rse.2006.05.009 <https://doi.org/10.1016/j.rse.2006.05.009> Glaciology Publication - Article PeerReviewed 2006 ftnerc https://doi.org/10.1016/j.rse.2006.05.009 2023-02-04T19:20:39Z Satellite radar altimeters and scatterometers deployed over ice sheets experience backscatter from the surface and from within the snowpack, termed surface and volume backscatter respectively. In order to assess the errors in satellite altimeter measurements it is vital to know where the return is originating from in the snowpack. This return can vary spatially and temporally. Seasonal variations in the volume backscatter can be a major complicating factor in the radar return from the percolation zone. Ground-based step-frequency radar was deployed in the percolation zone of the Greenland Ice Sheet at 1945 m elevation (69 51N, 47 15W). Previous measurements in this area made by scientists from the Byrd Polar Research Centre and the University of Kansas, undertaken prior to summer melt events, have shown the strongest backscatter from ice features at around 1 m depth buried beneath the previous end-of-summer surface. In autumn 2004, radar measurements in the Ku band with bandwidths of 1 and 8 GHz were made alongside detailed stratigraphic observations within a 1 km2 site. The radar results revealed no continuous reflecting horizons in the upper 3.5 m of the firn. Shallow cores and snowpits also indicated that there were no spatially continuous stratigraphic horizons across the study site. An average electromagnetic wave velocity of 2.11 ± 0.05 × 108 m s− 1 was determined for the upper metre of the firn. Surface and volume backscatter at vertical incidence were calculated using a standard model. The contribution of the surface backscatter to the total backscatter was on average 6 dB higher than that of the volume backscatter. However, at the higher 8 GHz bandwidth the strongest return frequently originated not from the surface but from within the upper 30 cm of the snowpack, most probably from thin ice layers. At 1 GHz bandwidth these ice layers were not always resolved; their return merged with the surface return, causing it to broaden, with the peak and leading edge moving down. Modelling using density and ... Article in Journal/Newspaper Byrd Polar Research Greenland Ice Sheet Natural Environment Research Council: NERC Open Research Archive Byrd Greenland Remote Sensing of Environment 104 4 361 373 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Glaciology |
spellingShingle |
Glaciology Scott, Julian B.T. Mair, Doug Nienow, Pete Parry, Victoria Morris, Elizabeth A ground-based radar backscatter investigation in the percolation zone of the Greenland ice sheet |
topic_facet |
Glaciology |
description |
Satellite radar altimeters and scatterometers deployed over ice sheets experience backscatter from the surface and from within the snowpack, termed surface and volume backscatter respectively. In order to assess the errors in satellite altimeter measurements it is vital to know where the return is originating from in the snowpack. This return can vary spatially and temporally. Seasonal variations in the volume backscatter can be a major complicating factor in the radar return from the percolation zone. Ground-based step-frequency radar was deployed in the percolation zone of the Greenland Ice Sheet at 1945 m elevation (69 51N, 47 15W). Previous measurements in this area made by scientists from the Byrd Polar Research Centre and the University of Kansas, undertaken prior to summer melt events, have shown the strongest backscatter from ice features at around 1 m depth buried beneath the previous end-of-summer surface. In autumn 2004, radar measurements in the Ku band with bandwidths of 1 and 8 GHz were made alongside detailed stratigraphic observations within a 1 km2 site. The radar results revealed no continuous reflecting horizons in the upper 3.5 m of the firn. Shallow cores and snowpits also indicated that there were no spatially continuous stratigraphic horizons across the study site. An average electromagnetic wave velocity of 2.11 ± 0.05 × 108 m s− 1 was determined for the upper metre of the firn. Surface and volume backscatter at vertical incidence were calculated using a standard model. The contribution of the surface backscatter to the total backscatter was on average 6 dB higher than that of the volume backscatter. However, at the higher 8 GHz bandwidth the strongest return frequently originated not from the surface but from within the upper 30 cm of the snowpack, most probably from thin ice layers. At 1 GHz bandwidth these ice layers were not always resolved; their return merged with the surface return, causing it to broaden, with the peak and leading edge moving down. Modelling using density and ... |
format |
Article in Journal/Newspaper |
author |
Scott, Julian B.T. Mair, Doug Nienow, Pete Parry, Victoria Morris, Elizabeth |
author_facet |
Scott, Julian B.T. Mair, Doug Nienow, Pete Parry, Victoria Morris, Elizabeth |
author_sort |
Scott, Julian B.T. |
title |
A ground-based radar backscatter investigation in the percolation zone of the Greenland ice sheet |
title_short |
A ground-based radar backscatter investigation in the percolation zone of the Greenland ice sheet |
title_full |
A ground-based radar backscatter investigation in the percolation zone of the Greenland ice sheet |
title_fullStr |
A ground-based radar backscatter investigation in the percolation zone of the Greenland ice sheet |
title_full_unstemmed |
A ground-based radar backscatter investigation in the percolation zone of the Greenland ice sheet |
title_sort |
ground-based radar backscatter investigation in the percolation zone of the greenland ice sheet |
publisher |
Elsevier |
publishDate |
2006 |
url |
http://nora.nerc.ac.uk/id/eprint/969/ https://doi.org/10.1016/j.rse.2006.05.009 |
geographic |
Byrd Greenland |
geographic_facet |
Byrd Greenland |
genre |
Byrd Polar Research Greenland Ice Sheet |
genre_facet |
Byrd Polar Research Greenland Ice Sheet |
op_relation |
Scott, Julian B.T.; Mair, Doug; Nienow, Pete; Parry, Victoria; Morris, Elizabeth. 2006 A ground-based radar backscatter investigation in the percolation zone of the Greenland ice sheet. Remote Sensing of Environment, 104 (4). 361-373. https://doi.org/10.1016/j.rse.2006.05.009 <https://doi.org/10.1016/j.rse.2006.05.009> |
op_doi |
https://doi.org/10.1016/j.rse.2006.05.009 |
container_title |
Remote Sensing of Environment |
container_volume |
104 |
container_issue |
4 |
container_start_page |
361 |
op_container_end_page |
373 |
_version_ |
1766382564052828160 |