摘要
利用国家气候中心给出的１９５１～１９９８年副高强度（Ｉｓ）、西界（Ｉｗ）。北界（ＩＮ）３个指数与国家气候中心同期的 ５００ ｈＰａ观测高度场分别作相关分析，并在高度场中分别找出几个有意义的点，用其高度计算副高３个指数Ｉ＇ｓ、Ｉ＇Ｎ和Ｉ＇ｗ，计算出Ｉ＇ｓ与Ｉｓ、Ｉ＇Ｎ与ＩＮ、Ｉ＇ｗ与Ｉｗ的相关系数均大于Ｉｓ、ＩＮ和Ｉｗ与单点高度的相关系数。对ＮＣＥＰ资料作同样分析，结果相同，说明可以利用 ５００ ｈＰａ高度场数值计算副高活动指数。于是利用重建的１８８０～１９５０年北半球高度场资料将副高３个指数向前恢复到１８８０年。对１８８０～１９９９年副高强度、西界、北界作功率谱及小波分析，发现副高强度。北界具有明显的４０年周期，西界具有明显的１６年周期，即副高指数的变化以低频振荡为主。
Firstly, correlation coefficients are calculated between the strength index (Is), the western limit index (Iw) and the northern limit index (IN) of the subtropical high (5TH) and the 500 hPa geopotential height set (provided by NCC) for the period of 1951~ 1998. Based on these correlation coefficients, some instructive points are selected in the 500 hPa geopotential height set by using which three STH indices I＇s, I＇N and I＇w are calculated. The correlation coefficients between , Ｉ＇s, I＇N, I ＇w are significant. Then the same analysis is carried out using NCEP 500 hPa geopotential height set, and the result is similar. It shows that using 500 hPa geopotential height set to calculate the three STH indices is practicable. So, the three STH indices are reconstructed back to the year of 1880 using the reconstructed 500 hPa geopotential height set from 1880 to 1950. After that, wavelet transformation is made to analyze the variabilities of Is, Iw and IN during 1880 and 1999, where by obvious 40.0-year-long-period oscillation of Is and IN, and 16.0-year-long-period oscillation of Iw are found. The inter-decadal oscillations of Is, Iw and IN are simultaneous.
出处
《大气科学》
CSCD
北大核心
2001年第6期787-797,共11页
Chinese Journal of Atmospheric Sciences
基金
国家重点基础研究发展规划项目G199804091-2
国家自然科学基金资助项目49635190共同资助
