基岩热膨胀对中国西南三维地表周年形变的影响分析OA北大核心CSTPCD

The annual signals in the Global Navigation Satellite System(GNSS)surface deformation time series include not only load deformation but also thermal expansion caused by the change of Earth's surficial temperature.Using a global three-dimensional thermoe-lastic deformation model,the thermal expansion effects of 39 crustal movement observation network of China(CMONOC)stations in the U,E,and N directions in southwestern China are estimated.Then the consistency between GNSS time series(before and after correcting thermal expansion effects)and load deformation derived from satellite gravity observations is analyzed,by comparing GNSS results with the calculations from Gravity Recovery and Climate Experience(GRACE)and GRACE Follow-On(GRACE-FO).After correcting for thermal expansion effects,the results indicate that the correspondence between the vertical component(U direction)of GNSS and the GRACE/GRACE-FO results is slightly weakened.On the horizontal component,the consistence in the E direction improves to some extent,but there exists a significant decrease in the N direction.The results presented in this paper in the southwest region are inconsistent with existing global or large-scale regional studies,indicating that the accuracy of estimating thermal expansion effects in different regions by using global thermoelastic deformation models needs to be further evaluated,and its impact on three-dimensional surface deformation is also worth further in-depth research.