国家自然科学基金资助项目40875040、41105055, 全球变化重大研究计划2012CB955902, 公益性行业 (气象) 科研专项GYHY201106016
利用NCEP/NCAR1961~2010年逐日平均再分析资料, 对中国东部地区前冬季节来临时间进行划分, 并探讨中国东部地区平均前冬季节来临时间偏早/偏晚与中国东部夏季降水之间的关系, 研究发现: (1) 中国东部前冬来临时间与中国东部夏季降水存在两个正相关带和两个负相关带, 且与其夏季雨带的位置大致吻合。正相关带分别位于华南、西南以及黄河以北的39°N~42°N一带、东北中南部等地区, 负相关带分别位于黄淮、江淮以及长江中下游一带和42°N以北的大部分地区。 (2) 统计特征表明: 中国东部地区前冬季节来临时间偏早的年份, II类雨型发生频率大于其气候发生频率, I类和III类雨型发生频率则比气候频率偏小; 前冬季节来临偏晚的年份, I类雨型发生的频率偏大, 而II类和III类雨型发生频率偏小, 典型年份的合成分析结果与雨带类型的统计结果相一致。反之, 从雨型与前冬来临时间的对应关系统计分析发现, I类雨型年份, 中国东部地区前冬季节来临时间显著偏晚年份占优, 而II类雨型年份, 前冬季节来临显著偏早年份占优, III类雨型年份对应关系不显著。总体而言, 季节来临早晚与雨带分布表现出一定的对应关系。 (3) 前冬来临早晚对应了不同的前期和同期海温、水汽和环流型, 受海—气相互作用的影响, 造成降水空间分布的不同。
By using NCEP/NCAR reanalysis datasets, the starting dates of preceding winters in eastern China have been divided from 1961 to 2010, the authors investigate the relationship between the onset date of preceding winter and the following summer precipitation in eastern China. Results indicate that there are two positive correlation bands and two negative correlation bands. The four bands are corresponding with the main rainbelts in eastern China in summer. The positive ones are located in South China, Southwest China, the region north of the Yellow River with latitudes between 39°N and 42°N, and central and southern Northeast China. The negative ones are in Huanghuai, Jianghuai, the middle and lower reaches of the Yangtze River, and most regions north of latitude 42°N. The statistical results show that the frequency of rainfall pattern II is larger than that of the climate state, those for both rainfall patterns I and III are less than that of the climate state when earlier preceding winters come. While for later winters, that for pattern I is larger than that of the climate state, those for both rainfall patterns II and III are much smaller than that of the climate state. The rainbelt outcomes from the statistics and composition analysis in the typical years are consistent with each other. The statistical results show that the later preceding winters are prime when it is pattern I, earlier winters for pattern II, and there is not significant relationship between the winter starting dates and pattern III. In a word, the patterns of precipitation are closely related to the starting dates of the seasons. The different starting dates of winters are corresponding to different air-sea interactions which result in different patterns of precipitation.
张世轩,支蓉,封国林,沈柏竹.中国东部地区前冬季节来临早晚与夏季降水的关系探究.大气科学,2012,36(3):564~578 ZHANG Shixuan, ZHI Rong, FENG Guolin, SHEN Baizhu. The Relationship between the Onset Date of Preceding Winter and Following Summer Rainfall in Eastern China. Chinese Journal of Atmospheric Sciences (in Chinese),2012,36(3):564~578复制