南极和格陵兰冰帽的变化与地球自转的非潮汐项

CHANGE OF ICE SHELL OF ANTARCTICA AND GREENLAND AND NON-TIDE TERM OF THE EARTH ROTATION

本文认为目前南极和格陵兰冰帽正处于冰积过程的观点存在较大的不可靠性；在讨论地球自转变化的非潮汐项时，仅考虑南极和格陵兰冰帽的变化是欠合理的；非潮汐项的影响可能主要来自冰期后的地壳反弹。

Over the last 18000 years, the Earth's crust has rebounding from the effects of the icesheet related with the last ice age. Many authors have discussed and concluded that the post- glacial rebound and long term changes in ice sheet mass balance created the secular changesin Earth,s momentum of inertia, which led the non - tidal component of the acceleration ofEarth rotation.In 1985, the Committee on Glaciology of US National Research Council estimated thatAntarctica and Greenland are likely to be accumulating ice at a rate that causes global sealevel to fall by 0. 6±0. 6mm/yr and 0. 1 ±0. 4mm/yr respectively. In this paper, we estimat ed the effects of global sea level falling mentioned above on the non -tidal term in Earth rota tlon.The result and discussion in this paper show that only the datum of ice sheet masschanges of Antarctica and Greenland, which correspond t0 ab0ut 41 % of mass changes of allice sheets on Earth, are adopted to estimate the non - tidal component of Earth rotationwould be incomplete; the global sea level is now continually going up would be more believe able; post - glacial rebound which is used to interpret the observed non - tidal acceleration ofEarth's rotation would be more reliable.