贵州省秋季连阴雨时空变化特征及典型过程研究

利用贵州省78个气象站1969—2019年秋季（9月1日—11月30日）的逐日降水量和日照时数资料以及同期NCEP/NCAR再分析资料，分析贵州省秋季无日照连阴雨发生频次、持续时间和时空分布特征，并选取5次典型过程进行环流诊断。结果表明：近51年来，贵州省秋季无日照雨日数10月最多，9月最少，秋季无日照雨日降水量最大的是9—10月，11月降水量最少。秋季累计贵州省平均无日照雨日数为27.3 d/a，贵州省多年平均秋季无日照降水量为183.2mm/a，均呈北多南少的分布型。贵州省东北部发生轻级（5～6 d）无日照连阴雨的频次最多，重级以上（10 d以上）无日照连阴雨过程主要发生在贵州省西北部。厄尔尼诺发生年，印度洋偶极子正位相，高原及其以西地区、印度洋多低值系统发展活动频繁，有利于贵州省出现连阴雨过程。

Spatial-temporal variation characteristics and typical processes of the continuous rain without sunshine in Autumn in Guizhou Province

Based on the daily precipitation and sunshine duration data of 78 meteorological stations in Guizhou province from 1969 to 2019 autumn (September 1 to November 30) and NCEP/NCAR reanalysis data of the same period were used, the spatial and temporal characteristics of continuous rain without sunshine were analyzed, and circulation patterns associated with five typical events were further discussed. The results shoe that the rainy day without sunshine is the highest in October and the lowest in September in Guizhou province in the recent 51 years. The precipitation amount in rainy days without sunshine is the highest in September and October, and the lowest in November. The average rainy days and precipitation amount without sunshine are 27.3 day and 183.2 mm in Guizhou Province, respectively, associated with a distribution pattern of more in the north and less in the south. The light continuous rainy day without sunshine (from 5 to 6 days) shows highest frequency in the northeast of Guizhou province, while the heavy continuous rainy day without sunshine (more than 10 days) occurs most frequently in the northwest of Guizhou province. In the El Ni?o developing years, the Indian Ocean Dipole is in positive phase, and the Tibetan plateau with its western areas and the Indian Ocean multi-low value system develop frequently, which is conducive to the occurrence of continuous rain without sunshine in Guizhou province.