中国东部区域性持续性强降水的低频特征及其海洋热力背景  

LOW-FREQUENCY OSCILLATION AND SST VARIATIONS OF REGIONAL PERSISTENT EXTREME PRECIPITATION IN EAST CHINA

作　　者：冯海山[1,2] 翟盘茂[2] 

机构地区：[1]南京信息工程大学,江苏南京210044 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081

出　　处：《热带气象学报》2016年第3期385-398,共14页Journal of Tropical Meteorology

基　　金：国家重点基础研究发展计划项目"我国持续性重大天气异常形成机理与预测理论和方法研究"(编号:2012CB417205)资助

摘　　要：基于1961-2010年夏半年（4—10月）中国逐日降水观测资料和NCEP／NCAR大气再分析资料，运用Butterworth滤波方法分析了中国低频降水特征、夏半年中国东部不同区域区域性持续性强降水与低频降水的关系，研究了海温对低频降水的影响。结果表明：低频降水贡献大值区位于中国东南部区域，某些年份，10～50天低频降水最大贡献达到40％，多年的平均贡献达到24％；在持续性强降水事件发生年，江淮和江南区域的20～50天的低频降水贡献显著增加，江淮和江南区域持续性强降水发生季节热带西北太平洋海表面温度呈现异常偏高，夏季热带西北太平洋海温异常增暖可能通过影响低频环流导致江淮和江南区域20—50天低频降水贡献的增加，进而增加持续性强降水事件发生的可能性。Based on daily rainfall data in china and NCEP/NCAR reanalysis dataset from April to October during 1961-2010, the low frequency oscillation of rainfall in China is analyzed by using the Butterworth bandpass filtering method. Through identifying regional persistent extreme precipitation events （PEPEs） , connection between PEPEs and the low frequency oscillation of rainfall and the impact of sea surface temperature （SST） are discussed. The results are as follows： the low frequency oscillation rainfall is most active over southeastern China. The maximum contribution of 10-50-day oscillation rainfall reaches 40% in some years but the average contribution is 24%. 20-50-day oscillation rainfall is more active over the Yangtze-Huaihe River Basin and in the region south of the Yangtze River accompanied with PEPEs. In the PEPEs years over the Yangtze-Huaihe River Basin and the region south to Yangtze River, the summer tropical northwestern Pacific SST exhibits positive anomalies. The positive SST anomalies likely enhance 20-50-day oscillation rainfall and increase the possibility of PEPEs occurrence over the region of the Yangtze-Huaihe River Basin and the region in the south of Yangtze River.

关 键 词：持续性强降水 低频降水 海表面温度 

分 类 号：P461[天文地球—大气科学及气象学]