四川省年昼雨的多尺度时间变化特征

The Temporal Variation Characteristics of Annual Daytime Rainfall in Sichuan Province

摘要: 利用四川省126个气象站点1961~2021年共61年逐日降水观测数据，采用集合经验模态分解(Ensemble Empirical Mode Decomposition，以下简称EEMD分解)详细地研究了四川省年昼雨的多时间尺度周期。结果表明：(1) EEMD分解表明各区域年昼雨存在显著的多时间尺度振荡主周期。川西南丘陵年昼雨的主要周期在准5a和准12.5a。川东北丘陵存在准4a、准7a和准15a的主要周期。成都平原存在准2a、6.5a和16a的主要周期。川西高原存在准5a、准10a和准16a的主要周期。川西南山地存在准7a和准20a的主要周期。

Abstract: Using daily precipitation observation data from 126 meteorological stations in Sichuan Province for a total of 61 years from 1961 to 2021, the Ensemble Empirical Mode Decomposition (EEMD) was used to study in detail the multi-time scale cycles of annual daytime rainfall in Sichuan Province. The results indicate that: (1) EEMD decomposition shows significant multi-time scale oscillation, with main periods of annual diurnal rain in each region. The main cycles of annual daytime rain in the southwestern hills of Sichuan are in Zhun 5a and Zhun 12.5a. The existence of the northeastern hills in Sichuan has the main cycles of Zhun 4a, Zhun 7a, and Zhun 15a. There are main cycles of quasi 2a, 6.5a, and 16a in the Chengdu Plain. There are main cycles of quasi 5a, quasi 10a, and quasi 16a in the western Sichuan Plateau. There are main cycles of quasi-7a and quasi-20a in the mountainous areas of southwestern Sichuan.