基岩热膨胀对中国西南三维地表周年形变的影响分析

he annual signals in the Global Navigation Satellite System (GNSS) surfacedeformation time series include not only load deformation but also thermal expansion causedby the change of Earths surficial temperature. Using a global three-dimensional thermoe#2;lastic deformation model, the thermal expansion effects of 39 crustal movement observationnetwork of China (CMONOC) stations in the U, E, and N directions in southwestern Chinaare estimated. Then the consistency between GNSS time series (before and after correctingthermal expansion effects) and load deformation derived from satellite gravity observationsis analyzed, by comparing GNSS results with the calculations from Gravity Recovery andClimate Experience (GRACE) and GRACE Follow-On (GRACE-FO). After correcting forthermal expansion effects, the results indicate that the correspondence between the verticalcomponent (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 paperin 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 byusing global thermoelastic deformation models needs to be further evaluated, and its impacton three-dimensional surface deformation is also worth further in-depth research.