CryoSat-2 delivers monthly and inter-annual surface elevation change for Arctic ice caps
| Autor: | L. Gray, David Burgess, Thorben Dunse, Kirsty Langley, Thomas V. Schuler, M. N. Demuth, Luke Copland |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Backscatter
010504 meteorology & atmospheric sciences 0211 other engineering and technologies 02 engineering and technology 01 natural sciences law.invention law Radar lcsh:Environmental sciences Earth-Surface Processes Water Science and Technology 021101 geological & geomatics engineering 0105 earth and related environmental sciences lcsh:GE1-350 geography geography.geographical_feature_category lcsh:QE1-996.5 Lead (sea ice) Firn Elevation Snow Arctic ice pack lcsh:Geology Radar altimeter 13. Climate action Climatology Environmental science |
| Zdroj: | The Cryosphere, Vol 9, Iss 5, Pp 1895-1913 (2015) |
| ISSN: | 1994-0424 |
| Popis: | We show that the CryoSat-2 radar altimeter can provide useful estimates of surface elevation change on a variety of Arctic ice caps, on both monthly and yearly time scales. Changing conditions, however, can lead to a varying bias between the elevation estimated from the radar altimeter and the physical surface due to changes in the contribution of subsurface to surface backscatter. Under melting conditions the radar returns are predominantly from the surface so that if surface melt is extensive across the ice cap estimates of summer elevation loss can be made with the frequent coverage provided by CryoSat-2. For example, the average summer elevation decreases on the Barnes Ice Cap, Baffin Island, Canada were 2.05 ± 0.36 m (2011), 2.55 ± 0.32 m (2012), 1.38 ± 0.40 m (2013) and 1.44 ± 0.37 m (2014), losses which were not balanced by the winter snow accumulation. As winter-to-winter conditions were similar, the net elevation losses were 1.0 ± 0.2 m (winter 2010/2011 to winter 2011/2012), 1.39 ± 0.2 m (2011/2012 to 2012/2013) and 0.36 ± 0.2 m (2012/2013 to 2013/2014); for a total surface elevation loss of 2.75 ± 0.2 m over this 3 year period. In contrast, the uncertainty in height change results from Devon Ice Cap, Canada, and Austfonna, Svalbard, can be up to twice as large because of the presence of firn and the possibility of a varying bias between the true surface and the detected elevation due to changing year-to-year conditions. Nevertheless, the surface elevation change estimates from CryoSat for both ice caps are consistent with field and meteorological measurements. For example, the average 3 year elevation difference for footprints within 100 m of a repeated surface GPS track on Austfonna differed from the GPS change by 0.18 m. |
| Databáze: | OpenAIRE |
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