琼中台重力非潮汐变化气压与海潮负荷改正

The Air Pressure and Ocean Tide Correction of Gravity Non-tidal Changes in Qiongzhong Seismic Station

本文对琼中台连续重力观测数据进行收集整理并处理,基于处理后的数据,进行了潮汐分析和非潮汐分析。潮汐分析采用VAV调和分析方法;非潮汐分析则分别进行了零漂改正、固体潮改正、气压改正和海潮改正。其中,零漂改正采用一般多项式拟合零漂的方法;气压改正采用VAV软件;海潮改正运用SPOTL程序,以NAO.99b潮汐模型计算了琼中台海潮负荷值。最终获得了改正后的琼中台重力非潮汐变化,结果表明琼中台的重力气压导纳值为-0.34×10^(-8)m/s^(2)/mbar,气压改正幅度约为10×10^(-8)m/s^(2),海潮改正幅度约为5×10^(-8)m/s^(2)。改正后,琼中台重力非潮汐变化数据,比仅进行零漂固体潮改正后的重力非潮汐变化数据中的潮汐信号更加微弱,说明进行海潮改正后的效果是明显的,该方法可进一步去除其中的潮汐信号。

In this paper,we collected the continuous observed gravity data of Qiongzhong seismic station,and performed tidal and non-tidal analysis based on the processed data.Tide analysis was done by using VAV harmonic method and Non-tidal analysis was done by performing zero drift correction,solid tide correction,barometric pressure correction,and tide correction.Among them,the zero drift correction was done by the general polynomial fitting zero drift method,the air pressure correction was performed by VAV software,and the tide correction was done by using the SPOTL program to calculate the tidal load of Qiongzhong seismic by NAO.99b tide model.Finally,we obtained the non-tidal changes about the gravity of Qiongzhong seismic station.Our results show that the gravity pressure admittance of Qiongzhong Platform is-0.34×10^(-8)m/s^(2)/mbar,the pressure correction range is about 10×10^(-8)m/s^(2),and the tide correction range is about 5×10^(-8)m/s^(2).After the above correction,the gravity non-tidal change data of Qiongzhong seismic station is weaker than the tidal signal in the gravity non-tidal change data after only zero drift solid tide correction.It shows that the effect of tide correction is obvious,and the tide signal can be further removed.