淮河流域夏季持续性降水与15～30天低频振荡的联系及前期信号  

Previous Signals of Summer Persistent Precipitation over the Huaihe River Basin and Its Relationship with 15- 30 Days Low-frequency Oscillation

作　　者：韩世茹 王黎娟[1,2] 于波[2] 

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心/气象灾害教育部重点实验室,南京210044 [2]安徽省气象局淮河流域气象中心,安徽蚌埠233040

出　　处：《气象与环境科学》2015年第4期22-32,共11页Meteorological and Environmental Sciences

基　　金：江苏省高校自然科学研究重大项目(14KJA170004);江苏省自然科学基金项目(BK20131432);淮河流域气象开放研究基金项目(HRM201202);江苏省"青蓝工程"资助

摘　　要：采用1961-2010年全国753站逐日降水资料、NCEP/NCAR逐日再分析资料、NOAA射出长波辐射资料和Hadley中心提供的全球海温资料,通过合成分析和Lanczos滤波等方法,讨论了淮河流域夏季持续性降水过程发生前后的大尺度流场及15~30 d低频环流特征,并寻找其前期信号。结果表明：1）在对流层高层和低层,我国东部地区低频气旋、反气旋在夏季持续性降水过程发生前后交替出现,分别通过调控南亚高压和西太平洋副热带高压东西位置变动从而影响降水过程。在对流层中层,夏季持续性强降水过程发生前后在淮河流域上空分别有“＋”、“-”、“＋”的低频高度中心存在。在持续性降水发生时,极地的冷空气与低纬度的暖湿空气在淮河流域上空交汇,有利于该地区降水。2）当前期冬季北太平洋地区海温和贝加尔湖东侧至鄂霍次克海地区500 h Pa位势高度场出现正异常时,会造成次年夏季淮河流域降水的15~30 d低频分量异常增多,从而使得淮河流域夏季出现持续性降水的可能性增大。Based on the 753 stations daily precipitation data in China from 1961 to 2010, the NCEP/NCAR daily reanalysis data, the NOAA Outing Longwave Radiation （OLR） data and the Hadley center of Global SST data, the features of large scale flowfields and characteristics of the 15-30 days low- frequency circulation before and after the summer persistent precipitation processes over Huaihe River Basin are discussed by the methods of wavelet and Lanczos filter. Furthermore, the previous signals of per- sistent precipitation over the Huaihe River Basin are analyzed. The results are as follows. 1 ） In the upper and lower troposphere, the low-frequency cyclones and anticyclones appear alternately over the east of China to regulate the South Asian high and the Western Pacific subtropical high position around the sum- mer persistent precipitation process occurring, affecting the precipitation in the Huaihe River Basin. In the middle troposphere, the ＂ ＋ ＂, ＂ - ＂ , ＂ ＋ ＂ low frequency geopotential height center alternately appears over the Huaihe River Basin around the summer persistent precipitation process occurring. At the beginning of the summer persistent precipitation, the pole cold air and the low latitude warm moist air meet in Huaihe River Basin, which is favorable to precipitation. 2）When the sea surface temperature in the North Pacific and the ge appear positive anomaly in opoten winter ial height at 500 hPa from the east of Lake Baikal to the Okhotsk area the 15--30 days low-frequency precipitation will increase over the Huaihe River Basin in the following summer, so that the persistent precipitation in summer is more likely to occur.

关 键 词：淮河流域 持续性降水 低频振荡 前期信号 

分 类 号：P468.024[天文地球—大气科学及气象学]