大气压力变化对武汉台站重力场观测的影响

The Influences of the Air Pressure Change on Gravity at Wuhan Station

利用全球 2°× 2 .5°、中国及邻区域 30′× 30′气压资料和 Farrell弹性地球模型负荷理论 ,采用数值积分方法 ,计算了大气压力变化对武汉台站重力场观测的影响。对 1990年 1月 1日至 12月 31日的数值结果分析表明 ,全球大气压力变化对武汉台站重力的影响峰对峰达 12微伽 ,大气重力导纳的年平均值为 -0 .2 6 0μGal/mba(1mba=1h Pa) ,这一结果同潮汐分析中由回归分析方法获得的导纳值相近。说明在利用超导重力仪观测资料应用于地球动力学研究之前 。

Using the global 2°×2.5° grid data,the local 30′×30′ grid data［1］ obtained from weather stations in China area and its vicinity,and Farrell's loading theory of elastic earth model method,study the influences of surface gravity due to air pressure changes.The air pressure corrections of the Wuhan earth's tidal observation have been calculated by numerical integrating to compute the expressions.The result shows that the volume is up to 12 μGal(1 Gal=1 cm/s2).That is means we need air pressure corrections to improve high precision observations such as superconducting gravimeter or FG5 absolute gravity meter.In comparison of the atmospheric gravity admittance obtained from tides analyses with our result,we find they are very close.Therefore,air pressure correction can be calculated by air pressure at the station and the atmospheric admittance from our model results.