Threshold sensitivity of shallow Arctic lakes and sublake permafrost to changing winter climate


Contact
guido.grosse [ at ] awi.de

Abstract

Interactions and feedbacks between abundant surface waters and permafrost fundamentally shape lowland Arctic landscapes. Sublake permafrost is maintained when the maximum ice thickness (MIT) exceeds lake depth and mean annual bed temperatures (MABTs) remain below freezing. However, declining MIT since the 1970s is likely causing talik development below shallow lakes. Here we show high-temperature sensitivity to winter ice growth at the water-sediment interface of shallow lakes based on year-round lake sensor data. Empirical model experiments suggest that shallow (1m depth) lakes have warmed substantially over the last 30years (2.4°C), withMABT above freezing5 of the last 7years.This is incomparison to slower ratesofwarming in deeper (3 m) lakes (0.9°C), with already well-developed taliks. Our findings indicate that permafrost below shallow lakes has already begun crossing a critical thawing threshold approximately 70 years prior to predicted terrestrial permafrost thaw in northern Alaska.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Peer revision
Scopus/ISI peer-reviewed
Publication Status
Published
Eprint ID
41737
DOI 10.1002/2016GL068506

Cite as
Arp, C. D. , Jones, B. M. , Grosse, G. , Bondurant, A. C. , Romanovsky, V. E. , Hinkel, K. M. and Parsekian, A. D. (2016): Threshold sensitivity of shallow Arctic lakes and sublake permafrost to changing winter climate , Geophysical Research Letters, 43 (12), pp. 6358-6365 . doi: 10.1002/2016GL068506


Share


Citation

Research Platforms
N/A

Campaigns


Actions
Edit Item Edit Item