大连地区雨季强降水气候特征分析
Climatic Characteristics of Heavy Rainfall in Rainy Season in Dalian

大连地区雨季强降水常造成城市内涝、山体滑坡、交通瘫痪等灾害，为提高气象预报保障能力，本文分析了大连多年气温、降水等长期资料，并用EOF分析方法归纳了发生强降水的主要天气形势模态，发现在全球变暖的背景下，大连年均气温也是振荡上升，冬季较夏季升温更明显，而雨季强降水的长期趋势是减少的，但仍会有极端强降水发生。年均气温的短周期为4a左右，长周期为16a左右，但2000年以后缩短为10~12a。雨季降水也具有4a左右短周期，还具有32a左右的较长周期，而10~12a的长周期在80、90年代变为8a左右，2000年以后变为6a左右。发生强降水的主要天气形势在1960~1989年呈阻塞高压(脊)型模态，而1990~2020年变为东北低涡型和北上台风型模态。
Heavy rainfall in rainy season in Dalian often causes urban waterlogging, landslides, traffic paralysis and other disasters. In order to improve the ability of weather forecast, this paper analyzes the long-term data of temperature and precipitation in Dalian, and summarizes the main synoptic situations with EOF analysis method. It is found that under the background of global warming, the annual average temperature in Dalian is also rising, and the temperature rises more obviously in winter than in summer, while the long-term trend of heavy rainfall in rainy season is decreasing, but extreme heavy rainfall will still occur. The average annual temperature has a short period of about 4 years and a long period of about 16 years, but it has been shortened to 10~12 years since 2000. The rainy season also has a short period of about 4 years and long periods of about 32 years and 10~12 years, while the long period of 10~12 years became 8 years in 1980s~1990s, and it be-came about 6 years after 2000. Through EOF analysis of the synoptic situations of heavy precipita-tion, it is found that from 1960 to 1989, it was a blocking high pressure (ridge) pattern, and from 1990 to 2020, it became the northeast vortex pattern and the northward typhoon pattern.