摘要： Geophysical fluids models for the atmosphere, ocean, and land hydrology usually do not properly enforce the conservation of mass either individually or collectively. Called the global mass balance (GMB) effect, these errors, if not corrected, will significantly affect the determination of the effect of geophysical fluids on the variation in the Earth's rotation rate or length of day (LOD). Here we analyze the seasonal budget of the excitation sources for LOD variation in comparison with corresponding observations. We find that (1) the combined mass‐induced excitations of LOD variation by geophysical fluids are brought to much better agreement with the observed upon accounting for the GMB effect; (2) the above can be further improved to almost perfect closure if the motion term of the atmospheric angular momentum (to be removed from the observed LOD variation in obtaining the mass‐induced LOD variation) is magnified by 7%, corroborating the finding of Chao and Yan (2010); and (3) the above quantities all agree remarkably well with the equivalent LOD variation determined via J2 variation from satellite laser ranging observations, indicating the usefulness of the latter as an independent measurement for mass transports in the geophysical fluids. Key Points Global mass balance effect significantly affects the LOD variation Mass‐induced LOD variation can be better explained with GMB correction Independent J2 changes are useful for mass‐induced LOD variation 其他題名： J. Geophys. Res 出版者： Washington, DC: Blackwell Publishing Ltd 出版日期： 2012-02 出處： Journal of Geophysical Research Atmospheres, 2012-02, Vol.117 (B2), p.n/a 資源來源： Wiley Online Library - AutoHoldings Journals 版權： Copyright 2012 by the American Geophysical Union 版權： 2015 INIST-CNRS 版權： Copyright 2012 by American Geophysical Union 識別號： ISSN: 0148-0227 識別號： ISSN: 2169-9313 識別號： ISSN: 2156-2202 識別號： EISSN: 2156-2202 識別號： EISSN: 2169-9356 識別號： DOI: 10.1029/2011JB008788
