The 1988-2003 Greenland ice sheet melt extent by passive microwave satellite data and a regional climate model

peer reviewed Measurements from ETH-Camp and JAR1 AWS (West Greenland) as well as coupled atmosphere-snow regional climate simulations have highlighted flaws in the cross-polarized gradient ratio (XPGR) technique used to identify melt from passive microwave satellite data. It was found that dense cl...

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Bibliographic Details
Published in:Climate Dynamics
Main Authors: Fettweis, Xavier, Gallée, Hubert, Lefebre, Filip, van Ypersele, Jean-Pascal
Format: Article in Journal/Newspaper
Language:English
Published: Springer Science & Business Media B.V. 2006
Subjects:
Online Access:https://orbi.uliege.be/handle/2268/14759
https://orbi.uliege.be/bitstream/2268/14759/1/Fettweis-2006-Draft.pdf
https://doi.org/10.1007/s00382-006-0150-8
Description
Summary:peer reviewed Measurements from ETH-Camp and JAR1 AWS (West Greenland) as well as coupled atmosphere-snow regional climate simulations have highlighted flaws in the cross-polarized gradient ratio (XPGR) technique used to identify melt from passive microwave satellite data. It was found that dense clouds (causing notably rainfall) on the ice sheet severely perturb the XPGR melt signal. Therefore, the original XPGR melt detection algorithm has been adapted to better incorporate atmospheric variability over the ice sheet and an updated melt trend for the 1988–2003 period has been calculated. Compared to the original algorithm, the melt zone area increase is eight times higher (from 0.2 to 1.7% year−1). The increase is higher with the improved XPGR technique because rainfall also increased during this period. It is correlated to higher atmospheric temperatures. Finally, the model shows that the total ice sheet runoff is directly proportional to the melt extent surface detected by satellites. These results are important for the understanding of the effect of Greenland melting on the stability of the thermohaline circulation.