Greenland ice sheet melt area, volume, and runoff from satellite and in situ observations
Abstract
Remote sensing provides surface melt area and regional mass change. In situ automatic weather station (AWS) data provide a relatively precise, but very local surface mass budget. Combining the two methods allows melt quantification for the entire Greenland ice sheet. We use interpolated near-surface air temperature from the GC-Net and PROMICE AWS networks, and remotely-sensed MODIS surface albedo to calculate melt with a temperature/albedo-index melt model. The calculations make use of albedo, combined with top-of-the-atmosphere solar radiation and cloud cover, to take into account absorbed shortwave radiation, the dominant melt parameter. In so doing the darkening due to the melt-albedo feedback is accounted. Calculated ablation is calibrated using AWS data. Assuming that surface albedo is a first-order indicator of the firn's available pore space and cold content, refreezing is parameterized as a function of it. Meltwater runoff for selected catchments is validated with river discharge data. The product: observation-based daily maps of near-surface air temperature, melt (extent and volume), and runoff for the Greenland ice sheet.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.C53D..08V
- Keywords:
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- 0726 CRYOSPHERE Ice sheets;
- 0762 CRYOSPHERE Mass balance 0764 Energy balance