夏季西太平洋副高特征及对湖泊水量变化的影响

The characteristics of the west-Pacific Subtropical high and its influences of the lake stream variation

采用NCEP/NCAR再分析资料、热带气旋频数和洪泽湖自然入湖水量等资料,借助EOF展开、相关分析等技术手段,对西太平洋副热带高压(WPSH,West Pacific Subtropical high)月、季、年变化特征以及对水文过程的影响等进行分析。结果表明:WPSH形态的显著特征表现为在暖季的北进和冷季的南退;随着WPSH脊线指数在暖季明显地呈现北进趋势,热带气旋源地发生频数也存在明显的增加趋势,并同步地在8月达到最大值;洪泽湖自然入湖水量也同步地伴随着WP-SH脊线指数的北进(南退)而增(减),并在7—8月间达到最大值;夏季西伸脊点与夏季距平高度场第一个特征向量的时间系数之间呈较好的反位相关系;夏季WPSH脊线与第二特征向量的时间系数之间呈较好的同位相关系;副高的面积和强度变化与西伸脊点位置之间呈较好的反位相关系。

By using the reanalyze data of NECP/NCAR, the frequencies of the tropical cyclone and the data of the natural influx stream of the Hongze Lake, and adopting the methods of EOF, correlation analysis and so on to analyze the variation characteristics of the west-Pacific Subtropical high about the month, the season, and year and the effects of the hydrology process. It is found that the marked feature of the WPSH is north entering in warm season and south retreating in cold season, and along with the WPSH ridge line index obviously presenting the north entering tendency, the frequencies of the tropical cyclone had the obvious tendency of increasing, reaching the maximum value in August. The natural in- flux stream of the Hongze Lake also increased or decreased, along with the WPSH ridge line index＇s north entering or south retreating and reached the maximum during July--August. The summer west stretching ridge and the first eigenvector＇s time function of summer anomaly high field had the obvious anti-phase relationship. The WPSH ridge line and the second eigenvector＇s time function had the obvious same-phase relationship. The change of the area and intensity of subtropical high and the west stretching ridge had obvious anti-phase relationship.