Widespread permafrost vulnerability and soil active layer increases over the high northern latitudes inferred from satellite remote sensing and process model assessments
Widespread permafrost vulnerability and soil active layer increases over the high northern latitudes inferred from satellite remote sensing and process model assessments
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DOI：
10.1016/j.rse.2015.12.046
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发表时间：
2016-03
影响因子：
13.5
通讯作者：
Hotaek Park;Youngwook Kim;J. Kimball
中科院分区：
文献类型：
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作者：
Hotaek Park;Youngwook Kim;J. Kimball
多年冻土覆盖范围和活动层厚度是评估高北方纬度生态水文过程以及潜在的陆-气碳和气候反馈的重要参数。我们开发了一种新的方法来推断PE从卫星微波遥感每日景观冻融（FT）状态。我们的研究结果文件，首次使用卫星微波FT观测监测冻土范围和条件。FT观测定义了近地表热状态，用于确定30年（1980-2009）卫星记录的永久冻土范围和稳定性。PE结果显示，对独立的库存和过程模型（CHANGE）的估计类似的性能，但在异质永冻土分区有较大的差异。多年冻土区总体平均值的持续下降（-0.33 million km 2 decade-1; p < 0.05）与区域变暖（0.4 °C decade-1; p < 0.01）相一致，而根据30年PE记录，超过40%（960万km 2）的多年冻土区容易退化。ALT估计确定卫星（中分辨率成像光谱仪）和ERA-Interim温度，和变化模拟，有利的独立的实地观察相比，并表明加深ALT趋势与近期气候变化下广泛的永久冻土退化一致。
Permafrost extent (PE) and active layer thickness (ALT) are important for assessing high northern latitude (HNL) ecological and hydrological processes, and potential land–atmosphere carbon and climate feedbacks. We developed a new approach to infer PE from satellite microwave remote sensing of daily landscape freeze–thaw (FT) status. Our results document, for the first time, the use of satellite microwave FT observations for monitoring permafrost extent and condition. The FT observations define near-surface thermal status used to determine permafrost extent and stability over a 30-year (1980–2009) satellite record. The PE results showed similar performance against independent inventory and process model (CHANGE) estimates, but with larger differences over heterogeneous permafrost subzones. A consistent decline in the ensemble mean of permafrost areas (− 0.33 million km2decade− 1; p < 0.05) coincides with regional warming (0.4 °C decade− 1; p < 0.01), while more than 40% (9.6 million km2) of permafrost areas are vulnerable to degradation based on the 30-year PE record. ALT estimates determined from satellite (MODIS) and ERA-Interim temperatures, and CHANGE simulations, compared favorably with independent field observations and indicate deepening ALT trends consistent with widespread permafrost degradation under recent climate change.