Factors influencing lake surface water temperature variability in West Greenland and the role of the ice sheet

<p>Subarctic West Greenland is populated by thousands of seasonally ice-free lakes. Using remotely sensed observations, we analyse the surface water temperatures of six lakes during 1995–2022 to identify factors influencing their variability. The connectivity to the Greenland Ice Sheet (GrIS)...

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Bibliographic Details
Main Authors: L. Carrea, C. J. Merchant, R. I. Woolway, N. McCarroll
Format: Article
Language:English
Published: Copernicus Publications 2025-08-01
Series:The Cryosphere
Online Access:https://tc.copernicus.org/articles/19/3139/2025/tc-19-3139-2025.pdf
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Summary:<p>Subarctic West Greenland is populated by thousands of seasonally ice-free lakes. Using remotely sensed observations, we analyse the surface water temperatures of six lakes during 1995–2022 to identify factors influencing their variability. The connectivity to the Greenland Ice Sheet (GrIS) has a clear influence on lake surface temperature, with ice-sheet-marginal lakes experiencing smaller average summer maximum temperature (<span class="inline-formula">&lt;6</span> <span class="inline-formula">°C</span>) and minimal interannual variability. A lake fed by a GrIS-originating river has the fastest seasonal response and largest seasonal amplitude with average maximum temperatures above 13 <span class="inline-formula">°C</span>. The seasonal cycle of surface water temperature for all studied lakes is asymmetrical, with faster warming observed after ice-off and a slower cooling of water towards winter freezing. We find that during the study period, the onset of positive stratification occurred earlier, at rates of up to 0.5 <span class="inline-formula">d yr<sup>−1</sup></span>, and that July–August temperatures increased at rates up to 0.1 <span class="inline-formula">°C yr<sup>−1</sup></span>, although the GrIS-connected lakes show smaller increases. Our analysis suggests that the main meteorological factor determining interannual variability of surface water temperature in the studied lakes is air temperature. This study highlights the important role of remote sensing for long-term monitoring of Greenland lakes under climate change.</p>
ISSN:1994-0416
1994-0424