The catastrophic thermokarst lake drainage events of 2018 in northwestern Alaska: fast-forward into the future
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Published:2020-12-01
Issue:12
Volume:14
Page:4279-4297
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ISSN:1994-0424
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Container-title:The Cryosphere
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language:en
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Short-container-title:The Cryosphere
Author:
Nitze IngmarORCID, Cooley Sarah W., Duguay Claude R.ORCID, Jones Benjamin M.ORCID, Grosse GuidoORCID
Abstract
Abstract. Northwestern Alaska has been highly affected by changing climatic patterns
with new temperature and precipitation maxima over the recent years. In
particular, the Baldwin and northern Seward peninsulas are characterized by
an abundance of thermokarst lakes that are highly dynamic and prone to lake
drainage like many other regions at the southern margins of continuous
permafrost. We used Sentinel-1 synthetic aperture radar (SAR) and Planet
CubeSat optical remote sensing data to analyze recently observed widespread
lake drainage. We then used synoptic weather data, climate model outputs and
lake ice growth simulations to analyze potential drivers and future pathways
of lake drainage in this region. Following the warmest and wettest winter on
record in 2017/2018, 192 lakes were identified as having completely or
partially drained by early summer 2018, which exceeded the average drainage
rate by a factor of ∼ 10 and doubled the rates of the previous
extreme lake drainage years of 2005 and 2006. The combination of abundant
rain- and snowfall and extremely warm mean annual air temperatures (MAATs),
close to 0 ∘C, may have led to the destabilization of permafrost
around the lake margins. Rapid snow melt and high amounts of excess
meltwater further promoted rapid lateral breaching at lake shores and
consequently sudden drainage of some of the largest lakes of the study
region that have likely persisted for millennia. We hypothesize that permafrost
destabilization and lake drainage will accelerate and become the dominant
drivers of landscape change in this region. Recent MAATs are already within
the range of the predictions by the University of Alaska Fairbanks' Scenarios Network for Alaska and Arctic Planning (UAF SNAP) ensemble climate predictions in
scenario RCP6.0 for 2100. With MAAT in 2019 just below 0 ∘C at the nearby Kotzebue, Alaska, climate station, permafrost aggradation in drained lake basins will become less likely after drainage, strongly decreasing the potential for freeze-locking carbon sequestered in lake sediments, signifying a prominent regime shift in ice-rich permafrost lowland regions.
Funder
European Research Council European Space Agency Helmholtz Association Office of Polar Programs National Science Foundation Natural Sciences and Engineering Research Council of Canada
Publisher
Copernicus GmbH
Subject
Earth-Surface Processes,Water Science and Technology
Reference96 articles.
1. Alexeev, V. A., Arp, C. D., Jones, B. M., and Cai, L.: Arctic sea ice
decline contributes to thinning lake ice trend in northern Alaska, Environ.
Res. Lett., 11, 074022, https://doi.org/10.1088/1748-9326/11/7/074022, 2016. 2. Antonova, S., Duguay, C., Kääb, A., Heim, B., Langer, M.,
Westermann, S., and Boike, J.: Monitoring Bedfast Ice and Ice Phenology in
Lakes of the Lena River Delta Using TerraSAR-X Backscatter and Coherence
Time Series, Remote Sens., 8, 903, https://doi.org/10.3390/rs8110903, 2016. 3. Arp, C. D. and Jones, B. M.: Geography of Alaska Lake Districts: Identification,
description, and analysis of lake-rich regions of a diverse and dynamic
state, U.S. Geological Survey Scientific Investigations Report 2008-5215,
40 pp., 2009. 4. Arp, C. D., Jones, B. M., Grosse, G., Bondurant, A. C., Romanovsky, V. E.,
Hinkel, K. M., and Parsekian, A. D.: Threshold sensitivity of shallow Arctic
lakes and sublake permafrost to changing winter climate, Geophys. Res.
Lett., 43, 6358–6365, https://doi.org/10.1002/2016gl068506, 2016. 5. Arp, C. D., Jones, B. M., Engram, M., Alexeev, V. A., Cai, L., Parsekian, A.,
Hinkel, K., Bondurant, A. C., and Creighton, A.: Contrasting lake ice
responses to winter climate indicate future variability and trends on the
Alaskan Arctic Coastal Plain. Environ. Res. Lett., 13, 125001, https://doi.org/10.1088/1748-9326/aae994, 2018.
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