Assessing present and future coastal moderation of extreme heat in the Eastern United States
Assessing present and future coastal moderation of extreme heat in the Eastern United States
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评估美国东部沿海极端高温当前和未来的缓和
DOI：
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发表时间：
2019
影响因子：
6.7
通讯作者：
J. Mankin
中科院分区：
文献类型：
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作者：
Colin Raymond;J. Mankin
气候模型显示，未来几十年极端炎热的天气将迅速增加。目前，凉爽的海洋空气在人口稠密的沿海地区为极端高温通风，减少了它的影响，但气候模型在多大程度上捕捉到了这种影响尚不确定。在这里，我们对沿海极热通风进行了全面的观测分析——其长度尺度、强度和区域模式——并评估了美国东部沿海的两个缩小比例的全球气候模型集合。我们发现，沿海地区比内陆地区低2°C - 4°C，导致暴露在35°C以上温度下的人口减少了近50%。大的季节和区域间变化与陆海温度差异密切相关。高分辨率模式低估了沿海冷却50%-75%，这意味着需要进行大量的时空变化的模式偏差校正，以创建沿海极端热的准确预估，而沿海极端热预计会随着人为强迫而大幅上升。我们的研究结果强调了基于区域和观测的观点对评估未来极端高温及其影响的重要性，以及对沿海到内陆地区的社区和司法管辖区进行有效的热风险管理的重要性。
Climate models suggest a rapid increase of extremely hot days in coming decades. Cool marine air currently ventilates extreme heat in populous coastal regions, diminishing its impacts, but how well climate models capture this effect is uncertain. Here we conduct a comprehensive observational analysis of coastal extreme-heat ventilation—its length scale, magnitude, and regional patterns—and evaluate two ensembles of downscaled global climate models along the eastern US coast. We find that coastal areas are 2 °C–4 °C cooler than ∼60 km inland, resulting in reductions near 50% in population exposure to temperatures above 35 °C. Large seasonal and inter-regional variations are closely linked with land-sea temperature contrasts. High-resolution models underestimate coastal cooling by 50%–75%, implying that substantial and spatiotemporally varying model bias correction is necessary to create accurate projections of coastal extreme heat, which is expected to rise considerably with anthropogenic forcing. Our results underline the importance of regionally- and observationally-based perspectives for assessing future extreme heat and its impacts, and for positioning effective heat-risk management for communities and jurisdictions that span coast-to-inland areas.