全球陆地水储量对地球自转变化的激发作用  

EXCITATION OF VARIATION OF EARTH’S ROTATION FROM GLOBAL CONTINENTAL WATER STORAGE

作　　者：廖德春[1] 廖新浩[2] 

机构地区：[1]中国科学院上海天文台上海200030 [2]中国科学院国家天文观测中心

出　　处：《天文学报》2000年第4期373-383,共11页Acta Astronomica Sinica

基　　金：国家攀登项目基金!(编号 970 2 3 1 0 0 3 );国家自然科学基金重点项目!(编 1 983 3 0 3 0 );中科院"九五"重大项目基金!(编号KJ

摘　　要：用美国环境预测中心和美国大气研究中心 (NCEP/NCAR) 40年重新分析计划气候数据同化系统 (CDAS)所得到的全球陆地水储量 (土壤湿度和积雪水当量 )数据 ,对地球自转变化 (极移和日长 )的激发作用作了分析 .结果表明 ,陆地水储量对周年地极移动正频分量的激发为 1 7.8mas,与大气激发相当 ,相位滞后约 48° .其中 ,积雪水当量的激发结果与用人卫遥感技术所得到的积雪水当量激发的正、负频率分量的振幅和相位都符合得很好 .用陆地水储量数据得到对日长变化周年分量的激发作用约 49μs,约占观测激发的1 5% ,相位滞后约 2 3° ;对日长变化半年分量的激发作用约 9μs,约占观测激发的 3% ,相位滞后约 1 2In this paper, a new set of global continental water storage data (soil moisture and water equivalent snow depth), which was obtained in Climate Data Assimilation System (CDAS) of the NMC/NCAR 40 Year Reanalysis Project, is used to calculate the excitation of variation of the Earth's rotation (polar motion and LOD). Then the results are compared with those astronomically observed as well as those inferred from wind term and pressure (IB) of atmospheric angular momentum (AAM). It is shown that the induced excitation for prograde component of annual wobble from continental water storage is about 17.8 mas, which is similar to that of AAM, and a phase lag in comparison with the astronomically observed one is about 48°. These values are quite different from the previous ones obtained by other authors. The excitations from the water equivalent snow depth for both prograde and retrograde components, however, are in good agreement with those obtained by Chao and O' Connor (1988) by using snow depth data of satellite remote sensors. The amplitude of excitation for annual component of LOD from continental water storage is about 49 μs, i.e. about 15% of the astronomically observed excitation, and the phase lage is about 23°. For semi annual component of LOD, the amplitude is about 9 μs and the phase lag is about 122°.

关 键 词：地球 自转变化 陆地水储量激发 冰雪水当量 激发作用 

分 类 号：P183.31[天文地球—天文学]