【摘要】 选用1991—2020年重庆市34个观测站逐日气温数据、NCEP/NCAR再分析资料、NOAA海表温度资料和国家气候中心130项大气环流参数数据，采用趋势分析、经验正交分解等方法分析重庆市倒春寒时空变化特征及其异常年的大气环流和前期海温特征。结果表明：重庆市出现倒春寒的站次年份段和区域差异明显，2001—2010年发生站次最少但强度最强，重庆西南部倒春寒站次最多、强度最强，倒春寒站次变化的主要空间模态为一致性异常分布。春季乌拉尔山高压脊异常增强，黑海至中国新疆地区、青藏高原和中国大部地区500 hPa高度场异常偏低，乌拉尔山至中国大部地区700 hPa温度场偏低，黑海至西伯利亚西风带环流减弱，中高纬经向环流显著增强，有利于冷空气南下，为重庆市倒春寒发生的主要大气环流背景。此外，前期冬季西太平洋暖池、孟加拉湾海温偏暖(冷)与重庆市倒春寒站次偏少(多)相关。更多还原

【Abstract】 Daily temperature data from 34 observation stations in Chongqing from 1991 to 2020,NCEP/NCAR reanalysis data, NOAA sea surface temperature data, and 130 atmospheric circulation parameters from the National Climate Center were utilized.Trend analysis and empirical orthogonal function decomposition methods were employed to analyze the spatiotemporal characteristics of late spring cold events in Chongqing, the atmospheric circulation and the preceding sea temperature features in anomalous years.The results indicated that the occurrence of late spring cold events in Chongqing exhibits significant spatial and temporal differences.The period 2001-2010 had the fewest occurrences but the strongest intensity.The southwestern part of Chongqing experienced the most frequent and the strongest late spring cold events.The primary spatial pattern of change in late spring cold event occurrences is characterized by a consistent anomaly distribution.In spring, the Ural high-pressure ridge is abnormally enhanced, while the 500 hPa geopotential height field is anomalously low from the Black Sea to Xinjiang, China, the Qinghai-Xizang Plateau, and most of China.The negative 700 hPa temperature anomaly is observed from the Ural Mountains to most of China.The westerly circulation from the Black Sea to Siberia is weakened, and the meridional circulation in the mid-high latitudes is significantly enhanced, facilitating the southward movement of cold air.This constitutes the main atmospheric circulation background for the occurrence of late spring cold event in Chongqing.Additionally, warmer(colder) sea surface temperatures in the Western Pacific Warm Pool and the Bay of Bengal during the preceding winter are correlated with fewer(more) occurrences of late spring cold events in Chongqing.更多还原