Dependence of Present and Future European Temperature Extremes on the Location of Atmospheric Blocking
Dependence of Present and Future European Temperature Extremes on the Location of Atmospheric Blocking
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DOI：
10.1029/2018gl077837
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发表时间：
2018-06-28
影响因子：
5.2
通讯作者：
Steiner, Andrea K.
中科院分区：
文献类型：
--
作者：
Brunner, Lukas;Schaller, Nathalie;Steiner, Andrea K.
研究了大气阻塞对欧洲热浪和寒潮的影响。第二代加拿大地球系统模式的50个成员的集合被用来量化的作用，内部变化的响应阻塞。我们发现，目前的阻塞极端温度链接是很好的代表相比，ERA-Interim，尽管在大多数合奏成员的阻塞频率显着低估。我们的结果显示，夏季、春季和秋季的阻塞与北方欧洲HW有很强的相关性。然而，我们也发现了一个强大的阻塞和HW发生在南欧在所有季节之间的关系。阻塞增加了CS频率，特别是在南欧的秋季，冬季和春季，但在夏季减少。对于未来，我们发现，阻塞将继续发挥重要作用，在发展的CS和HWS在所有season.Plain语言摘要大气阻塞描述了强大的和固定的高压系统在中纬度地区。它经常与地表极端天气有关，如寒流（CS）和热浪（HWs）。我们使用一个全球气候模型（第二代加拿大地球系统模型）与多种实现，并调查其表现在代表阻塞和温度极端的影响相比，现代（1979-2010年）条件下的ERA中期再分析。我们还展望了未来（2070-2099年）在高排放情景下的发展（代表性浓度路径8.5）。我们发现阻塞和极端温度之间的联系在欧洲以及代表在第二代加拿大地球系统模型相比，ERA-Interim，尽管阻塞发生在几乎所有的实现显着低估。我们的研究结果表明，在夏季，春季和秋季，阻塞对北方欧洲的HW产生了强烈的影响，HW的发生率增加了2倍以上。然而，在南欧，我们发现一个强大的阻塞和HW发生在所有季节之间的关系。阻塞增加CS频率在整个欧洲在秋季，冬季和春季，但减少CS在夏季。对于未来，我们发现，封锁将继续发挥重要作用，在发展的CS和HWS在所有季节。
The impact of atmospheric blocking on European heat waves (HWs) and cold spells (CSs) is investigated for present and future conditions . A 50-member ensemble of the second generation Canadian Earth System Model is used to quantify the role of internal variability in the response to blocking. We find that the present blocking-extreme temperature link is well represented compared to ERA-Interim, despite a significant underestimation of blocking frequency in most ensemble members. Our results show a strong correlation of blocking with northern European HWs in summer, spring, and fall. However, we also find a strong anticorrelation between blocking and HW occurrence in southern Europe in all seasons. Blocking increases the CS frequency particularly in southern Europe in fall, winter, and spring but reduces it in summer. For the future we find that blocking will continue to play an important role in the development of both CSs and HWs in all seasons.Plain Language Summary Atmospheric blocking describes strong and stationary high-pressure systems at midlatitudes. It is frequently connected to surface extremes such as cold spells (CSs) and heat waves (HWs). We use a global climate model (second generation Canadian Earth System Model) with multiple realizations and investigate its performance in representing blocking and the impact on temperature extremes compared to the ERA-Interim reanalysis for present-day (1979-2010) conditions. We also look into the development in the future (2070-2099) under a high-emission scenario (Representative Concentration Pathway 8.5). We find the link between blocking and temperature extremes in Europe well represented in the second generation Canadian Earth System Model compared to ERA-Interim, despite a significant underestimation of blocking occurrence in almost all realizations. Our results show a strong impact of blocking on HWs in northern Europe in summer, spring, and fall, increasing the HW occurrence by a factor 2 and more. However, in southern Europe we find a strong anticorrelation between blocking and HW occurrence in all seasons. Blocking increases the CS frequency in all of Europe in fall, winter, and spring but reduces CSs in summer. For the future we find that blocking will continue to play an important role in the development of both CSs and HWs in all seasons.