Future Global Convective Environments in CMIP6 Models
Future Global Convective Environments in CMIP6 Models
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DOI：
10.1029/2021ef002277
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发表时间：
2021-12-01
期刊：
影响因子：
8.2
通讯作者：
Tippett, Michael K.
中科院分区：
文献类型：
--
作者：
Lepore, Chiara;Abernathey, Ryan;Tippett, Michael K.
强对流风暴对气候变暖的响应在少数研究充分的地区之外知之甚少。在这里，从CMIP 6档案中的七个全球气候模型的预测，历史和未来的情景，用于探索全球响应的变量，描述了条件的可预测性发展的严重风暴。这些变量包括对流可用位能（CAPE）、对流抑制（CIN）、0-6 km垂直风切变（S 06）、风暴相对螺旋度（SRH）和协变量指数（即，恶劣天气代理）的联合收割机。为了更好地量化不确定性，了解变量对温度升高的敏感性，并呈现独立于特定场景的结果，我们将对流变量的变化视为每个系综成员全球平均温度升高的函数。有利的对流环境的增加表明，全球温度每升高摄氏度，总体频率增加约5%-20%，但区域并不均匀，高纬度地区，特别是北方半球，显示出更大的相对变化。这些变化的驱动机制是CAPE的强烈增加，这并没有被阻止对流（CIN）或改变风暴组织（S 06，SRH）的可能性的因素所抵消。恶劣天气代理与恶劣天气事件不同。因此，它们的预计增加不一定会转化为恶劣天气的发生，但它们使我们能够量化全球气温的增加将如何影响有利于恶劣天气的条件的发生。
The response of severe convective storms to a warming climate is poorly understood outside of a few well studied regions. Here, projections from seven global climate models from the CMIP6 archive, for both historical and future scenarios, are used to explore the global response in variables that describe favorability of conditions for the development of severe storms. The variables include convective available potential energy (CAPE), convection inhibition (CIN), 0-6 km vertical wind shear (S06), storm relative helicity (SRH), and covariate indices (i.e., severe weather proxies) that combine them. To better quantify uncertainty, understand variable sensitivity to increasing temperature, and present results independent from a specific scenario, we consider changes in convective variables as a function of global average temperature increase across each ensemble member. Increases to favorable convective environments show an overall frequency increases on the order of 5%-20% per degrees C of global temperature increase, but are not regionally uniform, with higher latitudes, particularly in the Northern Hemisphere, showing much larger relative changes. The driving mechanism of these changes is a strong increase in CAPE that is not offset by factors that either resist convection (CIN), or modify the likelihood of storm organization (S06, SRH). Severe weather proxies are not the same as severe weather events. Hence, their projected increases will not necessarily translate to severe weather occurrences, but they allow us to quantify how increases in global temperature will affect the occurrence of conditions favorable to severe weather.