How well will ICESat-2 do in measuring glacier mass change in western North America?
Abstract
The ICESat-2 mission is expected to provide exceptional detail about seasonal-to-annual elevation change for the Greenland and Antarctic ice sheets over the next three to five years. With a repeat cycle of 91 days, ICESat-2 also provides opportunities to measure elevation change for mountain glaciers. The degree to which these measurements will provide an assessment of mass change for western North America is uncertain, however, given the region's topographic complexity and distribution of small ice masses. We evaluate the feasibility of using ICESat-2 to derive regional assessment of glacier mass change for western North America by examining how effectively the laser samples ice-covered terrain. Our assessment considers glaciers in British Columbia and Alberta that represent close to 90% of the region's total ice-covered area. ICESat-2 sampling efficiency is first evaluated by comparing laser footprint locations to the current hypsometry of ice-covered terrain. We evaluate sampling biases by comparing elevation and elevation change recorded for repeat ICESat-2 measurements to regionally-based elevation change data over glaciers obtained through: i) bi-annual airborne LiDAR surveys that routinely survey several hundred individual glaciers; and ii) estimates of glacier elevation change derived from stereoscopic satellite imagery. We also consider the effect that density assumptions play in converting elevation to mass change. Although sampling biases due to orbit configuration are minor, persistent cloud cover, long repeat cycle and deep seasonal snow cover present notable challenges for deriving unbiased assessments of glacier mass change at the scale of individual mountain ranges.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C22A..05M
- Keywords:
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- 0720 Glaciers;
- CRYOSPHERE;
- 0758 Remote sensing;
- CRYOSPHERE;
- 0762 Mass balance;
- CRYOSPHERE;
- 0776 Glaciology;
- CRYOSPHERE