全球水分布和气压变化对固体地球质心位置的影响

CHANGES OF THE SOLID GEOCENTRE DUE TO SEASONAL VARIATIONS OF GROUND WATER AND AIR PRESSURE

根据IERS决议，国际地球参考系的原点是地球固体部分、海洋和大气的共同质量中心因此，地球上流体部分质量分布变化会改变固体地球质心相对于国际地球参考系原点的位置变化．空间技术如SLR和GPS的观测结果表明，固体地球质心可能有幅度达10毫米的位置变化，所以给出固体地球质心位置变化以及地球物理原因已成为重要问题.本文采用了全球4000多个地面气象台站从1949到1982年的月平均降水、温度和气压值，对水和大气的分布变化引起的固体地球质心位置变化进行了计算，得出水储量分布变化对固体地球质心运动比气压分布变化有更大的贡献，固体地球质心位置变化的最大值可达4毫米．

According to the IERS Definition, the origin of international Termstrial ReferenceFrame(rrap is defined as the combined mass centre of the solid earth. the oceans andthe atmosphere. So the variation of liqind mass distribution would cause the inchon ofthe solid geocentre relative to the ITRF origin.The observational results from the spacetechniques(such as SLR. GPS)show that the inchon of the solid geocentre may be inexceed of 10mm. Then, it is very important to study the solid geocentre inchon anditS geophysical causes. In mis psper, on using the meteorological monthly data whichis about more than 4000 meteorological stations all over the world from 1949 to1982, we eshmate the solid geocentre inchon due to the seasonal distribution of airpressure and ground water. The conclusion is that the solid geocentre inchon due toground water may have a larger contribution than that of air pressure, and the relativemaximum value of the inchon of the solid geocentre is about 4mm.