不同亚洲夏季风指数与我国降水量的相关性分析

Correlation Analysis between Different Asian Summer Monsoon Index and Precipitation in China

摘要: 亚洲夏季风是十分复杂的天气系统，并且其对我国降水量有着重要影响。目前已建立了许多亚洲夏季风指数定量地衡量亚洲夏季风的强弱，但由于各个指数的侧重点不同，导致其对我国降水量的相关性也有所差异。文章选取目前已建立的11种亚洲夏季风指数，根据定义利用1981~2016年NCEP/NCAR再分析资料计算各指数序列，同时分析其与我国降水量之间的空间相关性。结果表明：不同季风子系统对我国降水量影响范围不同，南亚夏季风指数主要与华北地区夏季降水存在正相关关系；东亚夏季风指数与我国西南、东部地区存在强相关性。根据定义将亚洲季风指数按所使用的要素类型分为气压场类、风场类、环流场类和综合类，以不同气候要素定义的季风指数其影响范围亦不同。此外，东亚夏季风指数影响区域的年内变率与我国雨带变率一致。

Abstract: The Asian summer wind is a very complex weather system, and it has an important impact on precipitation in China. Many Asian summer wind indices have been established to quantitatively measure the strength of the Asian summer winds, but due to the different focuses of each index, their relevance to the precipitation in China is also different. In this paper, we select 11 Asian summer wind indices that have been established so far, and use the NCEP/NCAR reanalysis data from 1981 to 2016 to calculate the sequence of each index according to the definition, and analyze the spatial correlation between them and the precipitation in China at the same time. The results show that different monsoon subsystems have different ranges of influence on precipitation in China, and the South Asian summer wind index mainly has a positive correlation with summer precipitation in North China; the East Asian summer wind index has a strong correlation with the southwestern and eastern regions of China. According to the definition of the Asian monsoon index, the Asian monsoon index is categorized into baroclinic field, wind field, circulation field, and composite field according to the type of elements used, and the specific characteristics and the scope of application are briefly described in the paper. In addition, the intra-annual variability of the East Asian Monsoon Index in the area of influence is consistent with the variability of the rain band in China.