文章基本信息

标题：Increased rainfall stimulates permafrost thaw across a variety of Interior Alaskan boreal ecosystems
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作者：Thomas A. Douglas ; Merritt R. Turetsky ; Charles D. Koven 等
期刊名称：npj Climate and Atmospheric Science
电子版ISSN：2397-3722
出版年度：2020
卷号：3
期号：1
页码：1-7
DOI：10.1038/s41612-020-0130-4
出版社：Nature Publishing Group
摘要：Earth’s high latitudes are projected to experience warmer and wetter summers in the future but ramifications for soil thermal processes and permafrost thaw are poorly understood. Here we present 2750 end of summer thaw depths representing a range of vegetation characteristics in Interior Alaska measured over a 5 year period. This included the top and third wettest summers in the 91-year record and three summers with precipitation close to mean historical values. Increased rainfall led to deeper thaw across all sites with an increase of 0.7 ± 0.1 cm of thaw per cm of additional rain. Disturbed and wetland sites were the most vulnerable to rain-induced thaw with ~1 cm of surface thaw per additional 1 cm of rain. Permafrost in tussock tundra; mixed forest; and conifer forest was less sensitive to rain-induced thaw. A simple energy budget model yields seasonal thaw values smaller than the linear regression of our measurements but provides a first-order estimate of the role of rain-driven sensible heat fluxes in high-latitude terrestrial permafrost. This study demonstrates substantial permafrost thaw from the projected increasing summer precipitation across most of the Arctic region.