Future increases in Arctic lightning and fire risk for permafrost carbon
Future increases in Arctic lightning and fire risk for permafrost carbon
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DOI：
10.1038/s41558-021-01011-y
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发表时间：
2021-04-05
影响因子：
30.7
通讯作者：
Randerson, James T.
中科院分区：
文献类型：
--
作者：
Chen, Yang;Romps, David M.;Randerson, James T.
闪电是气候变化的指示器和驱动力。本文利用卫星闪电频率观测和ERA5再分析，发现北极区夏季闪电的空间分布与对流有效势能(CAPE)和降水的乘积有很强的正相关关系。将这一关系应用于气候模型比较项目第五阶段高排放情景(RCP8.5)的气候预测显示，在被永久冻土覆盖的地区，开普敦(86+/-22%)和降水量(17+/-2%)增加，导致到本世纪末(2081-2100年)夏季闪电增加112+/-38%。北部林线未来的闪光率与南部480公里处北方森林的当前水平相当。我们假设，闪电的增加可能会引发火-植被反馈，从而使北极冻土带更多的燃烧加速了北方树木的北移，从而有可能加速与多年冻土碳释放相关的正反馈。闪电活动的变化在气候变化下是不确定的。作者预测，到本世纪末，北极夏季闪电可能会增加一倍以上，这可能会引发闪电袭击冻土带的野火，以及相关的永久冻土碳释放。
Lightning is an indicator and a driver of climate change. Here, using satellite observations of lightning flash rate and ERA5 reanalysis, we find that the spatial pattern of summer lightning over northern circumpolar regions exhibits a strong positive relationship with the product of convective available potential energy (CAPE) and precipitation. Applying this relationship to Climate Model Intercomparison Project Phase 5 climate projections for a high-emissions scenario (RCP8.5) shows an increase in CAPE (86 +/- 22%) and precipitation (17 +/- 2%) in areas underlain by permafrost, causing summer lightning to increase by 112 +/- 38% by the end of the century (2081-2100). Future flash rates at the northern treeline are comparable to current levels 480 km to the south in boreal forests. We hypothesize that lightning increases may induce a fire-vegetation feedback whereby more burning in Arctic tundra expedites the northward migration of boreal trees, with the potential to accelerate the positive feedback associated with permafrost soil carbon release.Changes in lightning activity are uncertain under climate change. The authors project that summer lightning in the Arctic is likely to more than double by the end of the century, with implications for lightning-strike tundra wildfires and associated carbon release from permafrost.