HR: 1330h
AN: G23B-01    [Abstracts]
TI: GRACE estimates as a constraint on non-tidal oceanic contribution to polar wobble
AU: Zhong, M
EM: zmzm@asch.whigg.ac.cn
AF: Institute of Geodesy and Geophysics,CAS, XU Dong Road 54, Wuhan, HB 430077 China
AU: * Xu, H
EM: hsuh@asch.whigg.ac.cn
AF: Institute of Geodesy and Geophysics,CAS, XU Dong Road 54, Wuhan, HB 430077 China
AU: Yang, H
EM: hsuh@asch.whigg.ac.cn
AF: Institute of Geodesy and Geophysics,CAS, XU Dong Road 54, Wuhan, HB 430077 China
AB: Contributions of ocean bottom pressure and oceanic current to polar wobble are evaluated by using two oceanic data assimilation products. One product comes from Scripps Institution of Oceanography (ECCO), and the other is the Simple Ocean Data Assimilation (SODA) developed at University of Maryland. The results show that seasonal fluctuations in these two assimilated ocean angular momentum (OAM) models agree with each other better along the Greenwich meridian than along the 90­aE meridian. Furthermore, seasonal OAM changes for ECCO are much closer to non-atmospheric residual, than those for SODA. However, seasonal OAM changes for SODA along the Greenwich meridian compares better than those for ECCO to non-atmospheric-hydrologic residual, in which annual and semiannual signals of land hydrologic angular momentum of a climate model, are considered, and annual signal is also compatible with the GRACE-derived land one along the 90­aE meridian. It is likely that annual ECCO change along the 90­aE meridian is overestimated according to the angular momentum conservation law in the Earth system. Consequently, the oceanic role in polar wobble should be further examined. Keywords: Oceanic Angular Momentum (OAM), polar wobble, Earth Rotation
DE: 1200 GEODESY AND GRAVITY
DE: 1223 Ocean/Earth/atmosphere interactions (3339)
DE: 1239 Rotational variations
SC: Geodesy [G]
MN: 2005 Joint Assembly