Rapid ablation zone expansion amplifies north Greenland mass loss

Since the early 1990s, the Greenland ice sheet (GrIS) has been losing mass at an accelerating rate, primarily due to enhanced meltwater runoff following atmospheric warming. Here, we show that a pronounced latitudinal contrast exists in the GrIS response to recent warming. The ablation area in north...

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Bibliographic Details
Published in:Science Advances
Main Authors: Noël, Brice (author), van de Berg, Willem Jan (author), Lhermitte, S.L.M. (author), van den Broeke, Michiel R. (author)
Format: Article in Journal/Newspaper
Language:English
Published: 2019
Subjects:
Online Access:http://resolver.tudelft.nl/uuid:a174eb48-7aae-4fbd-8194-aaab2eccc381
https://doi.org/10.1126/sciadv.aaw0123
Description
Summary:Since the early 1990s, the Greenland ice sheet (GrIS) has been losing mass at an accelerating rate, primarily due to enhanced meltwater runoff following atmospheric warming. Here, we show that a pronounced latitudinal contrast exists in the GrIS response to recent warming. The ablation area in north Greenland expanded by 46%, almost twice as much as in the south (+25%), significantly increasing the relative contribution of the north to total GrIS mass loss. This latitudinal contrast originates from a different response to the recent change in large-scale Arctic summertime atmospheric circulation, promoting southwesterly advection of warm air toward the GrIS. In the southwest, persistent high atmospheric pressure reduced cloudiness, increasing runoff through enhanced absorption of solar radiation; in contrast, increased early-summer cloudiness in north Greenland enhanced atmospheric warming through decreased longwave heat loss. This triggered a rapid snowline retreat, causing early bare ice exposure, amplifying northern runoff. Mathematical Geodesy and Positioning