根据人卫激光测距、GRACE和地球物理模型求解地球低阶重力场季节变化  

Variations of the Earth's Gravity Field from GRACE,Geophysical Model and Satellite Laser Ranging

作　　者：曲伟菁[1,2] 吴斌[1] 周旭华[1] 

机构地区：[1]中国科学院上海天文台,上海200030 [2]中国科学院研究生院,北京100049

出　　处：《测绘学报》2012年第6期904-909,共6页Acta Geodaetica et Cartographica Sinica

基　　金：国家自然科学基金(1173049;11003036;11173048;10873029);国家测绘局测绘基础研究基金(10-01-13);上海市空间导航与定位技术重点实验室资助(06DZ22101)

摘　　要：利用2002年4月至2010年10月的Lageos1和Lageos2激光卫星观测数据、GRACE以及地球物理模型3种独立的方法计算地球低阶重力场系数J2的变化ΔJ2,其中大气变化的贡献分别按反变气压计(IB)和非反变气压计(NIB)两种假设进行计算。通过分析ΔJ2的季节特性可得:①在NIB假设下大气质量变化引起的J2变化的周年振幅比其在IB假设下引起的ΔJ2变化的周年振幅大3倍左右,相位相差47°;②大气和陆地水的质量变化对ΔJ2周年变化的贡献占主导地位,海洋的影响较小;③大气、海洋和陆地水质量变化引起ΔJ2半年振幅和相位值与SLR得到的振幅和相位值吻合较差,尤其是在IB假设下大气得到的结果与SLR结果相差更大;④SLR、GRACE和地球物理模型3种独立方法得到的ΔJ2周年项之间吻合相对较好。GRACE得到的周年振幅比SLR得到的周年振幅大50%左右,SLR观测得到的ΔJ2周年振幅介于在NIB和IB两种假设下地球物理模型得到的结果之间,GRACE与SLR得到的ΔJ2半年的振幅相同。Several independent time series of variations J~ in Earth＇s gravity field are compared from GRACE, geophysical model and satellite laser ranging（SLR） for the period April 2002 to cteber 2010. It is computed the atmospheric induced J2 variations for both inverted-barometer （IB） and non-inverted-barometer （NIB） response of the oceans. The results of the comparison show that@ the annual term amplitude of ]2 in NIB case is bigger by a3 times than that in IB case, the difference of the both phase is 47~~ @ at the annual frequency, atmospheric pressure and surface ground water effects are the dominate contributors~ @ for the semi-annual term, the amplitudes and phases of the atmospheric pressure, ocean and surface ground water do not agree very well, especially for the results of the atmospheric pressure in IB case~ @ GRACE, geophysical model and SLR annual J2 estimates agree well. The amplitude from GRACE is bigger about 50 percent. The annual amplitude from SLR is between that from the geophysical model in IB case and in NIB case. The semi-annual amplitude estimated from GRACE and SLR is the same.

关 键 词：地球物理模型 SLR GRACE 地球低阶重力场变化 

分 类 号：P223[天文地球—大地测量学与测量工程]