华南前汛期(4～6月)降水异常特征及其与我国近海海温的关系

分析了华南前汛期降水异常，认为华南前汛期降水峰值所在月有明显的年际变化。前汛期总的降水变化趋势不明显。前汛期降水异常存在多尺度振荡，前汛期降水偏多年，偏少年的同期全国降水分布存在明显相反的特征，且通过对华南前汛期降水异常与其前期（上一年6－8月）我国近海SSTA的相关分布，找到一个稳定的影响华南前汛期降水的敏感海区，同时讨论了它的敏感时段及其同期的SSTA，后期的距平环流场特征与华南前汛期降水异常，同期的距平环流场特征的关系，最后分析了该敏感海区SSTA与全球海域SSTA的关系，由此提出一个我国近海SSTA影响华南前汛期降水异常的可能机制。     

台风“利奇马”(1909)影响期间上海强降水成因诊断分析

2019年第9号台风“利奇马”(1909)在8月9—11日影响上海期间造成了严重的风雨影响。基于ERA5逐小时再分析资料和上海区域高时空分辨率的地面观测资料,采用非地转Q矢量分解等方法诊断分析了此次强降水成因。结果表明,台风“利奇马”在上海造成的强降水主要来自台风东侧的螺旋雨带。强降水区东南西北各边界的相对湿度在垂直方向上随时间的变化差异明显,水汽的垂直输送和大气整层水汽含量在台风强降水中起重要作用。进一步利用非地转Q矢量分解方法揭示了东边界的大尺度和北边界的中尺度系统在强降水中起主要作用。台风登陆时呈现出整层大气被抬升之后最大强迫中心由高层向低层下传的态势,且此下传效应中尺度比大尺度强迫更加明显,从而有利于强降水的发生。     

ON THE RELATIONSHIP BETWEEN PRECIPITATION ANOMALIES IN THE FIRST RAINING SEASON (APRIL-JUNE) IN SOUTHERN CHINA AND SST OVER OFFSHORE WATERS IN CHINA

Precipitation anomalies in the first raining season of southern China were analyzed, with the suggestion that there are obvious interannual variation of peak values. In the raining season, the general tendency of precipitation is not obvious and the anomalous oscillation is multi-scale. Corresponding to years of more or less precipitation in the raining season, there are sharply opposite distribution across the nation in the simultaneous periods. In addition, by studying the distribution of correlation between anomalous precipitation in southern China in the first raining season and SSTA over offshore waters of China in the preceding period (June ~ August of the previous year), a sensitive zone of waters has been found that has steady effect on the precipitation of southern China in the season. Discussions are also made of the sensitive period, its simultaneous SSTA and subsequent anomalous circulation field in relation to precipitation anomalies and simultaneous circulation field in the first raining season of southern China. In the last part of the work, relationship between the SSTA in the sensitive zone and global SSTA is analyzed. A possible mechanism by which SSTA in offshore Chinese waters affects the precipitation anomalies in the first raining season of southern China is put forward.