摘要
介绍了小波振幅分析方法和小波振周谱分析方法的解析表达 ,然后利用小波振幅分析方法研究了195 0～ 2 0 0 3年日长近 12 0d准周期振荡的时频规律 (国际地球自转中心提供的 196 2～ 2 0 0 3年的日长变化以及根据美国环境预测中心提供的大气角动量换算的 195 0～ 2 0 0 3年大气激发的日长变化 )。此外 ,还利用小波振周谱分析方法研究了同一时段内厄尔尼诺 3、4区海水温度异常年际变化的时频特征 ,并将它与日长近12
The time-frequency variations of the geodetic and atmospheric induced pseudo-120-day length-of-day changes (ΔLOD)from 1950 to 2003 are studied by a wavelet amplitude spectrum method, and they are compared with the inter-annual variation (2 to 6 years) of sea surface water temperature anomaly (SSTA) in Regions 3,4 of El Nino. The results show that the amplitude of the pseudo-120-day ΔLOD reaches its relative summit when an El Nino above the 4-year period occurs, except for the atmospheric induced case in 1966. In addition, it is also found that there is a uniform change in the time-frequency figures of pseudo-120-period ΔLOD between the scale of 80 days and 110 days, and in the time-frequency figure of El Nino events below the 4-year period. All of these results indicate that the amplitude variations of the pseudo-period LOD changes at the scale of 80-120 days are modulated by El Nino events.
出处
《武汉大学学报（信息科学版）》
EI
CSCD
北大核心
2003年第6期703-705,共3页
Geomatics and Information Science of Wuhan University
基金
中国科学院知识创新工程资助项目 (KZCX2 10 6)
地球空间环境与大地测量教育部重点实验室开放研究基金资助项目
关键词
厄尔尼诺
小波振幅分析
海水表面温度异常
日长变化
准周期振荡
时频
length-of-day change(ΔLOD)
wavelet amplitude spectrum method
sea surface water temperature anomaly (SSTA)
El Nino
