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Atmospheric drivers of Greenland surface melt revealed by self-organizing maps

J. Mioduszewski; A. K. Rennermalm; A. Hammann; Marco Tedesco; E. U. Noble; J. C. Stroeve; T. L. Mote

Title:
Atmospheric drivers of Greenland surface melt revealed by self-organizing maps
Author(s):
Mioduszewski, J.
Rennermalm, A. K.
Hammann, A.
Tedesco, Marco
Noble, E. U.
Stroeve, J. C.
Mote, T. L.
Date:
Type:
Articles
Department(s):
Lamont-Doherty Earth Observatory
Volume:
121
Persistent URL:
Book/Journal Title:
Journal of Geophysical Research: Atmospheres
Geographic Area:
Greenland
Abstract:
Recent acceleration in surface melt on the Greenland ice sheet (GrIS) has occurred concurrently with a rapidly warming Arctic and has been connected to persistent, anomalous atmospheric circulation patterns over Greenland. To identify synoptic setups favoring enhanced GrIS surface melt and their decadal changes, we develop a summer Arctic synoptic climatology by employing self-organizing maps. These are applied to daily 500 hPa geopotential height fields obtained from the Modern Era Retrospective Analysis for Research and Applications reanalysis, 1979–2014. Particular circulation regimes are related to meteorological conditions and GrIS surface melt estimated with outputs from the Modèle Atmosphérique Régional. Our results demonstrate that the largest positive melt anomalies occur in concert with positive height anomalies near Greenland associated with wind, temperature, and humidity patterns indicative of strong meridional transport of heat and moisture. We find an increased frequency in a 500 hPa ridge over Greenland coinciding with a 63% increase in GrIS melt between the 1979–1988 and 2005–2014 periods, with 75.0% of surface melt changes attributed to thermodynamics, 17% to dynamics, and 8.0% to a combination. We also confirm that the 2007–2012 time period has the largest dynamic forcing relative of any period but also demonstrate that increased surface energy fluxes, temperature, and moisture separate from dynamic changes contributed more to melt even during this period. This implies that GrIS surface melt is likely to continue to increase in response to an ever warmer future Arctic, regardless of future atmospheric circulation patterns.
Subject(s):
Climatic changes
Synoptic climatology
Ice sheets
Atmospheric thermodynamics
Publisher DOI:
https://doi.org/10.1002/2015JD024550
Item views
8
Metadata:
text | xml
Suggested Citation:
J. Mioduszewski, A. K. Rennermalm, A. Hammann, Marco Tedesco, E. U. Noble, J. C. Stroeve, T. L. Mote, , Atmospheric drivers of Greenland surface melt revealed by self-organizing maps, Columbia University Academic Commons, .

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