Linear response of east Greenland’s tidewater glaciers to ocean/atmosphere warming
Abstract
Predicting the retreat of tidewater outlet glaciers forms a major obstacle to forecasting the rate of mass loss from the Greenland Ice Sheet. This reflects the challenges of modeling the highly dynamic, topographically complex, and data-poor environment of the glacier–fjord systems that link the ice sheet to the ocean. To avoid these difficulties, we investigate the extent to which tidewater glacier retreat can be explained by simple variables: air temperature, meltwater runoff, ocean temperature, and two simple parameterizations of “ocean/atmosphere” forcing based on the combined influence of runoff and ocean temperature. Over a 20-y period at 10 large tidewater outlet glaciers along the east coast of Greenland, we find that ocean/atmosphere forcing can explain up to 76% of the variability in terminus position at individual glaciers and 54% of variation in terminus position across all 10 glaciers. Our findings indicate that (i) the retreat of east Greenland’s tidewater glaciers is best explained as a product of both oceanic and atmospheric warming and (ii) despite the complexity of tidewater glacier behavior, over multiyear timescales a significant proportion of terminus position change can be explained as a simple function of this forcing. These findings thus demonstrate that simple parameterizations can play an important role in predicting the response of the ice sheet to future climate warming.
Citation
Cowton , T , Sole , A , Nienow , P , Slater , D A & Christoffersen , P 2018 , ' Linear response of east Greenland’s tidewater glaciers to ocean/atmosphere warming ' , Proceedings of the National Academy of Sciences of the United States of America , vol. 115 , no. 31 , pp. 7907-7912 . https://doi.org/10.1073/pnas.1801769115
Publication
Proceedings of the National Academy of Sciences of the United States of America
Status
Peer reviewed
ISSN
0027-8424Type
Journal article
Rights
© 2018 The Author(s). This work has been made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1073/pnas.1801769115
Description
This work was funded by NERC grants NE/K015249/1 and NE/K014609/1 to PN and AS respectively and a NERC studentship to DS.Collections
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