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

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 I...

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Bibliographic Details
Published in:The Cryosphere
Main Authors: T. J. Ballinger, T. L. Mote, K. Mattingly, A. C. Bliss, E. Hanna, D. van As, M. Prieto, S. Gharehchahi, X. Fettweis, B. Noël, P. C. J. P. Smeets, C. H. Reijmer, M. H. Ribergaard, J. Cappelen
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2019
Subjects:
Environmental sciences
GE1-350
Geology
QE1-996.5
Arctic
Baffin Bay
Greenland
Baffin
Ice Sheet
North Atlantic
Northwest Atlantic
Sea ice
The Cryosphere
Tundra
Online Access:https://doi.org/10.5194/tc-13-2241-2019
https://doaj.org/article/a020bb5e2e8a4fd395ac380ef50ad664
Description
Summary: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.

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