中国月极端高温对大气涛动的响应

Monthly extreme high-temperature response to atmospheric oscillation in China

利用广义帕雷托分布(GPD)模型研究了中国1960—2007年740站月极端高温(monthly extreme high-temperature,MEHT)对大气涛动响应的分布特征.通过构建空间GPD模型,分别将北大西洋涛动(NAO)和南方涛动(SO)作为强迫因子引入模型,考察了9种情景下MEHT响应的区域规律.结果表明NAO和SO对MEHT分布有潜在强迫作用,MEHT产生响应的空间分布主要集中在东北、青藏高原东部及长江、黄河流域和华南部分地区.具体表现为:1)MEHT明显依赖于NAO的敏感区为东北,其次为青藏高原东部;对SO有明显响应的中心区域集中在青藏高原东部、长江流和黄河流域.2)NAO与SO对MEHT的非线性叠加强迫不明显,各自的影响以单独传播为主,即两者同时作为强迫源时,MEHT受强迫的范围未出现明显减弱或增强.其原因可能与SO和NAO的时空分布差异有关.

Based on monthly data from 1960 to 2007 of 740 stations in China, we investigate the response of monthly extreme high-temperature （MEHT） to atmospheric oscillation through spatial Generalized Pareto Distribution （GPD） model. Here we take different groupings of North Atlantic Oscillation （NAO） and Southern Oscillation （SO） as forcing parameters in the model and evaluate the response of MEHT to atmospheric oscillation in 9 different scenarios. Results show that the impact of NAO/SO on MEHT of China is significant and different responsen to different regions, i.e. the regions showing significant dependence of MEHT on atmospheric oscillation are Northeast China, the eastern part of the Tibetan Plateau, reaches of Yangtze and Yellow river and part of South China. To be specific, 1） MEHT obviously dependent on NAO is the north-east areas, followed by the eastern Tibet Plateau; MEHT obviously dependent on SO is mainly the Eastern Tibet Plateau and the Yangtze River and Yellow River and etc. ; 2） Nonlinear addition effect of NAO and SO is not obvious, their impact on MEHT is mainly one-way, that is, both acting as forcing factors, most of the region forced by them is not significantly weakened or strengthened, and the reason may be related to differences in the atmosphere oscillation spatial and temporal distribution.