佘山台倾斜固体潮观测的海潮负荷改正

Ocean Tidal Loading Correction to Tilt Observations at Sheshan Station

采用FARRELL的负荷理论以及最新的TPXO6海潮模型和中国近海潮汐资料计算了海潮负荷对佘山台倾斜固体潮的影响,采用BAYTAP-G调和分析软件对佘山台倾斜固体潮观测进行了处理,获得不同潮波的潮汐参数。在此基础上进行海潮负荷改正。负荷改正后,东西分量的振幅因子和相位滞后与理论值较为接近,而南北分量的半日波振幅因子与理论值仍有较大的偏离。结果说明,佘山台倾斜东西分量主要受海潮负荷的影响,超过60%,甚至达到96%(O1);而南北分量受到的非潮汐的影响要比东西分量受到的影响大,如N2波甚至高达70%,但是这也可能是和海潮模型在近海的不精确有关。

With the latest ocean tide model of TPXO6 and China regional tidal data, the tilt tidal loading are calculated based on Farrell＇s load theory. Simultaneously, the tilt tidal parameters are obtained by processing the tilt observations at Sheshan station using BAYTAP-G software for harmonic analysis. After that, the loading correction is carried out. The numerical results show, after correction, that tilt tidal parameters of EW component are closer to the theoretical ones while the values of NS component for semidiurnal tides are still apart from the theoretical ones. This means that the EW component of tilt is mainly influeneed by ocean tide, which is more than 60%, even reaches to 96% for O1. And the NS component cf tilt is more influenced by the non-tidal effects than EW component. For example, for N2 constituent, the non-tidal effects are up to 70%. However the inaccuracy of the ocean tide model in local area may eontrihute more to the high percentage.