Equator-to-pole temperature differences and the extra-tropical storm track responses of the CMIP5 climate models
Equator-to-pole temperature differences and the extra-tropical storm track responses of the CMIP5 climate models
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DOI：
10.1007/s00382-013-1883-9
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发表时间：
2014-09-01
期刊：
影响因子：
4.6
通讯作者：
Woollings, T. J.
中科院分区：
文献类型：
--
作者：
Harvey, B. J.;Shaffrey, L. C.;Woollings, T. J.
本文旨在了解导致CMIP 5气候模式风暴轴预测中大范围扩散的物理过程。特别是，风暴路径的气候变化响应之间的关系，如2-6天的平均海平面气压方差，和赤道到极点的温度差在对流层的上部和下部的水平进行了研究。在南半球的上层和下层对流层温度差异的响应是相关的整个模型，因此，他们分享类似的协会与风暴路径的响应。在大范围内，风暴轴响应与温差响应相关，基于任一水平温差的简单线性回归模型捕捉了平均风暴轴响应的空间模式，并解释了风暴轴响应的30%至60%的模型间方差。在北方，两种温差的响应相关不显著，与风暴轴响应的关系较为复杂。在夏季，对流层低层温差的响应主导了风暴轴响应的模式间传播。在冬季，高、低温差的响应都起作用。结果表明，有可能通过限制热带和极地地区变暖的相对幅度来减少风暴轴响应的传播。
This paper aims to understand the physical processes causing the large spread in the storm track projections of the CMIP5 climate models. In particular, the relationship between the climate change responses of the storm tracks, as measured by the 2-6 day mean sea level pressure variance, and the equator-to-pole temperature differences at upper- and lower-tropospheric levels is investigated. In the southern hemisphere the responses of the upper- and lower-tropospheric temperature differences are correlated across the models and as a result they share similar associations with the storm track responses. There are large regions in which the storm track responses are correlated with the temperature difference responses, and a simple linear regression model based on the temperature differences at either level captures the spatial pattern of the mean storm track response as well explaining between 30 and 60 % of the inter-model variance of the storm track responses. In the northern hemisphere the responses of the two temperature differences are not significantly correlated and their associations with the storm track responses are more complicated. In summer, the responses of the lower-tropospheric temperature differences dominate the inter-model spread of the storm track responses. In winter, the responses of the upper- and lower-temperature differences both play a role. The results suggest that there is potential to reduce the spread in storm track responses by constraining the relative magnitudes of the warming in the tropical and polar regions.