东亚西风急流与我国华西秋雨降水的相关分析

Correlation Analysis of East Asian Westerly Jet and Autumn Rainfall in West China

摘要: 华西秋雨是我国华西地区特有的降水现象，东亚西风急流也是影响我国降水的重要大气环流之一。研究东亚西风急流和我国华西秋雨的关系，对预测我国未来华西秋雨有重要意义。本文使用相关分析、EOF-CCA分析等方法研究东亚西风急流与华西秋雨的关系，其中使用了华西秋雨指数和东亚西风急流的相关指数，得出了以下结论：华西秋雨变化的整体趋势为华西秋雨强度随着时间增长而减弱，存在华西秋雨异常偏强年和异常偏弱年；秋季东亚西风急流整体趋势为急流位置维持于39˚N，144.3˚E，急流强度维持于36.3 ms⁻¹左右；东亚西风急流和华西秋雨的7年滑动相关呈周期性变化，滑动周期为15年；秋季东亚西风急流强度区的西部与华西地区的东北部呈正相关，与华西地区的西部呈负相关。

Abstract: The Autumn Rainfall in West China is a unique precipitation phenomenon in West China, and the East Asia Westerly Jet is also one of the important atmospheric circulations affecting precipitation in China. Studying the relationship between the East Asia Westerly Jet and the Autumn Rain in West China is of great significance for predicting the future Autumn Rain in West China. In this paper, correlation analysis and EOF-CCA analysis are used to study the relationship between the East Asia Westerly Jet and the Autumn Rain in West China. The modified autumn rain index and the correlation index of East Asia Westerly Jet are used. The following conclusions are drawn: the overall trend of the Autumn Rain in West China is that the intensity of Autumn Rain in West China decreases with the increase of time, and there are abnormal strong and weak years of Autumn Rain in West China; The overall trend of the East Asia Westerly Jet is that the position of the East Asia Westerly Jet is maintained at 39 degrees N, 144.3 degrees E, and the intensity of the East Asia Westerly Jet is maintained at about 36.3 ms⁻¹; the seven-year sliding correlation between the East Asia Westerly Jet and the Autumn Rain in West China shows periodic change, with a sliding period of 15 years; the West of the intensity region of the East Asia Westerly Jet is positively correlated with the northeast of West China in autumn, and negatively correlated with the west of West China.