大气和带谐潮汐对日长高频变化的影响  

Influence of Atmosphere and Zonal Tides on High-Frequency Variation of Length of Day

作　　者：顾震年[1] 金文敬[1] 

机构地区：[1]中国科学院上海天文台,上海200030

出　　处：《云南天文台台刊》2003年第2期53-59,共7页Publications of the Yunnan Observatoty

摘　　要：用国际地球自转服务提供的高精度日长序列ΔLOD(IERS(EOP99C04),和由美国国家环境预报中心(NCEP)对过去的气象资料进行重新分析和计算,提供的轴向大气角动量序列(AAM)来研究大气和带谐潮汐对地球自转变化(ΔLOD)中高频振荡激发的贡献。由Multitaper功率谱分析表明,ΔLOD序列在9.13d(天)、13.63d、13.66d、27.55d周期时呈现出比较强的谱峰,这些谱都在95%的显著性水平以上,有比较强的信噪比。从ΔLOD和AAM之差值序列谱分析结果及地球带谐响应系数k的估计,表明大气不是ΔLOD的高频变化的主要激发源。根据理论潮汐周期可知,有可能存在其它的激发源,如海洋对地球自转变化的激发。这还有待于进一步深入探讨。In this paper the atmospheric contribution to highfrequency variation of the earth rotation is studied with the series of LOD (EOP(IERS) 99 C04)) and axial component of the atmospheric angular momentum (AAM) supplied by International Earth Rotation Service(IERS) and U.S.National Centers for Environmental Prediction(NCEP),by which the past meteorological data were re-analyzed and computed,respectively.The spectral peaks of 9.13, 13.66, 13.63, 13.66, 27.55 days,which have large ratio of signal to noise,exist in the LOD series and the significant level of these spectral term is greater than 90% by using the Multitaper power spectrum method.From the results of spectral analysis on difference between AAM and LOD,and estimation of the Earths zonal response coefficient k,it is found that the atmosphere is not the main excitation source for high-frequency variation of the Earth Rotation,but the main contribution is from ocean tides based on the theoretical tidal periods.

关 键 词：气象 带谐潮汐 大气 高频振荡 地球自转 日长高频变化 

分 类 号：P183.5[天文地球—天文学]