利用谐波分析、功率谱分析的方法，对全国730个站点自1951～2000年逐日降水资料进行气候平均分析，研究全国降水季节内振荡的分布特征。研究结果表明，中国大部分地区的降水主要以季节变化为主，而在长江中下游流域主要以季节内振荡为...利用谐波分析、功率谱分析的方法，对全国730个站点自1951～2000年逐日降水资料进行气候平均分析，研究全国降水季节内振荡的分布特征。研究结果表明，中国大部分地区的降水主要以季节变化为主，而在长江中下游流域主要以季节内振荡为主。气候平均下降水的准双周振荡和Madden and Julian Oscillation（简称MJO）的振幅都在4月份开始加强，在11月份开始减弱，而MJO全年表现都很显著，准双周振荡主要在夏季显著；MJO主要分布在36°N以南的长江巾下游地区，准舣周振荡主要分布在115°E以西的内陆。展开更多
With the methods of REOF （Rotated Empirical Orthogonal Function）, the summer precipitation from 43 stations over eastern China for the 1901 - 2000 period was examined. The results show that South China and Southwest...With the methods of REOF （Rotated Empirical Orthogonal Function）, the summer precipitation from 43 stations over eastern China for the 1901 - 2000 period was examined. The results show that South China and Southwest China, the middle and lower reaches of Changiiang River, North China and the southwestern of Northeast China are the three main areas of summer rainfall anomaly. Furthermore, correlation analysis is used in three time series of three mostly summer rainfall modes and four seasonal Pacific SSTA （Sea Surface Temperature Anomaly）, and the results suggest that the Pacific SSTA which notably causes the summer rainfall anomaly over eastern China are the SSTA of the preceding winter over Kuroshio region of Northwest Pacific, SSTA of the preceding spring in the eastern and central equatorial Pacific, and SSTA of the current summer in the central region of middle latitude. The relationship between summer precipitation over eastern China and SSTA of Pacific key regions was further verified by SVD （Singular Value Decomposition） analysis. The composite analysis was used to analyze the features of atmospheric general circulation in the years of positive and negative precipitation anomaly. Its results were used to serve as the base of numerical simulation analysis.展开更多
Based on the data of SST and NCEP/NCAR reanalysis data, the relationship is analyzed of spring SSTA in the Kuroshio region with summer precipitation in China, summer 500 hPa field and water vapor transport, using the ...Based on the data of SST and NCEP/NCAR reanalysis data, the relationship is analyzed of spring SSTA in the Kuroshio region with summer precipitation in China, summer 500 hPa field and water vapor transport, using the methods of Morlet wave, correlation and composite analysis. The results show that annual and interdecadal change of spring SST in the Kuroshio region is distinct. Spring SST displays a significantly increasing trend and there exist different periodic oscillations in the Kuroshio region, with the 23-year periodic oscillation being the most obvious. Troughs and ridges in the mid- and higher- latitudes turn deeper in high Kuroshio SSTA years. At the same time, the western Pacific subtropical high strengthens and stretches westwards. As a result, the warm / wet air from the west of the subtropical high locates in the mid- and lower- reaches of the Yangtze River and south China and summer rainfall in the above regions increases accordingly. Composite anomalous water vapor flux fields indicate that the vapor transport from the South China Sea and western Pacific and the vapor from the north converge over the mid- and lower- reaches of the Yangtze River and south China, which results in the increase of the summer rainfall in the mid- and lower- reaches of the Yangtze River and south China. On the contrary, the summer rainfall in the mid- and lower- reaches of the Yangtze River and south China decreases correspondingly in low Kuroshio SSTA years.展开更多
文摘利用谐波分析、功率谱分析的方法，对全国730个站点自1951～2000年逐日降水资料进行气候平均分析，研究全国降水季节内振荡的分布特征。研究结果表明，中国大部分地区的降水主要以季节变化为主，而在长江中下游流域主要以季节内振荡为主。气候平均下降水的准双周振荡和Madden and Julian Oscillation（简称MJO）的振幅都在4月份开始加强，在11月份开始减弱，而MJO全年表现都很显著，准双周振荡主要在夏季显著；MJO主要分布在36°N以南的长江巾下游地区，准舣周振荡主要分布在115°E以西的内陆。
基金Natural Science Foundation of China(40331010)Study Project of Jiangsu Key Laboratory ofMeteorological Disaster (KLME050304)
文摘With the methods of REOF （Rotated Empirical Orthogonal Function）, the summer precipitation from 43 stations over eastern China for the 1901 - 2000 period was examined. The results show that South China and Southwest China, the middle and lower reaches of Changiiang River, North China and the southwestern of Northeast China are the three main areas of summer rainfall anomaly. Furthermore, correlation analysis is used in three time series of three mostly summer rainfall modes and four seasonal Pacific SSTA （Sea Surface Temperature Anomaly）, and the results suggest that the Pacific SSTA which notably causes the summer rainfall anomaly over eastern China are the SSTA of the preceding winter over Kuroshio region of Northwest Pacific, SSTA of the preceding spring in the eastern and central equatorial Pacific, and SSTA of the current summer in the central region of middle latitude. The relationship between summer precipitation over eastern China and SSTA of Pacific key regions was further verified by SVD （Singular Value Decomposition） analysis. The composite analysis was used to analyze the features of atmospheric general circulation in the years of positive and negative precipitation anomaly. Its results were used to serve as the base of numerical simulation analysis.
基金National Planning Project for the Research and Development of Key National FundamentalResearch (2004CB418303)Innovative Project for Training Post Graduates in Jiangsu Province (E30000008098-2)
文摘Based on the data of SST and NCEP/NCAR reanalysis data, the relationship is analyzed of spring SSTA in the Kuroshio region with summer precipitation in China, summer 500 hPa field and water vapor transport, using the methods of Morlet wave, correlation and composite analysis. The results show that annual and interdecadal change of spring SST in the Kuroshio region is distinct. Spring SST displays a significantly increasing trend and there exist different periodic oscillations in the Kuroshio region, with the 23-year periodic oscillation being the most obvious. Troughs and ridges in the mid- and higher- latitudes turn deeper in high Kuroshio SSTA years. At the same time, the western Pacific subtropical high strengthens and stretches westwards. As a result, the warm / wet air from the west of the subtropical high locates in the mid- and lower- reaches of the Yangtze River and south China and summer rainfall in the above regions increases accordingly. Composite anomalous water vapor flux fields indicate that the vapor transport from the South China Sea and western Pacific and the vapor from the north converge over the mid- and lower- reaches of the Yangtze River and south China, which results in the increase of the summer rainfall in the mid- and lower- reaches of the Yangtze River and south China. On the contrary, the summer rainfall in the mid- and lower- reaches of the Yangtze River and south China decreases correspondingly in low Kuroshio SSTA years.
