Greenland Ice Sheet late-season melt: investigating multiscale drivers of K-transect events

Date

2019-08-30

Authors

Ballinger, Thomas J.
Mote, Thomas L.
Mattingly, Kyle
Bliss, Angela C.
Hanna, Edward
van As, Dirk
Prieto, Melissa
Gharehchahi, Saeideh
Fettweis, Xavier
Noel, Brice

Journal Title

Journal ISSN

Volume Title

Publisher

European Geosciences Union

Abstract

One consequence of recent Arctic warming is an increased occurrence and longer seasonality of above-freezing air temperature episodes. There is significant disagreement in the literature concerning potential physical connectivity between high-latitude open water duration proximate to the Greenland Ice Sheet (GrIS) and late-season (i.e., end-of-summer and autumn) GrIS melt events. Here, a new date of sea ice advance (DOA) product is used to determine the occurrence of Baffin Bay sea ice growth along Greenland's west coast for the 2011–2015 period. Over the 2-month period preceding the DOA, northwest Atlantic Ocean and atmospheric conditions are analyzed and linked to late-season melt events observed at a series of on-ice automatic weather stations (AWSs) along the K-transect in southwestern Greenland. Surrounding ice sheet, tundra, and coastal winds from the Modèle Atmosphérique Régional (MAR) and Regional Atmospheric Climate Model (RACMO) provide high-resolution spatial context to AWS observations and are analyzed along with ERA-Interim reanalysis fields to understand the meso-to-synoptic-scale (thermo)dynamic drivers of the melt events. Results suggest that late-season melt events, which primarily occur in the ablation area, are strongly affected by ridging atmospheric circulation patterns that transport warm, moist air from the subpolar North Atlantic toward west Greenland. Increasing concentrations of North Atlantic water vapor are shown to be necessary to produce melt conditions as autumn progresses. While thermal conduction and advection off south Baffin Bay open waters impact coastal air temperatures, local marine air incursions are obstructed by barrier flows and persistent katabatic winds along the western GrIS margin.

Description

Keywords

Greenland Ice Sheet, arctic warming, qtmospheric conditions, late-season melt, Geography and Environmental Studies

Citation

Ballinger, T. J., Mote, T. L., Mattingly, K., Bliss, A. C., Hanna, E., van As, D., Prieto, M., Gharehchahi, S., Fettweis, X., Noël, B., Smeets, P. C. J. P., Reijmer, C. H., Ribergaard, M. H., & Cappelen, J. (2019). Greenland Ice Sheet late-season melt: Investigating multiscale drivers of K-transect events. The Cryosphere, 13, pp. 2241-2257.

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© 2019 The Author(s).

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This work is licensed under a Creative Commons Attribution 4.0 International License.

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