基岩热膨胀对中国西南三维地表周年形变的影响分析  

Analysis of the Impact of Bedrock Thermal Expansion on Three-Dimensional Sur cial Annual Deformation in Southwest China

作　　者：王鹏飞 王松筠 李进[1,2] 齐朝祥 WANG Peng-fei;WANG Song-yun;LI Jin;QI Zhao-xiang(Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China;Center for Space Research,University of Texas at Austin,Austin 78759,USA)

机构地区：[1]中国科学院上海天文台,上海200030 [2]中国科学院大学天文与空间科学学院,北京100049 [3]美国德克萨斯大学奥斯汀分校空间研究中心,奥斯汀78759

出　　处：《天文学进展》2024年第2期315-334,共20页Progress In Astronomy

基　　金：国家自然科学基金(42394132,12003057,12173069,11703065);国家重点研发计划(2021YFC3200203,2018YFE0118500)。

摘　　要：全球导航卫星系统(Global Navigation Satellite System,GNSS)可以监测获取地表形变时间序列,其中的周年信号除包含负荷形变外,还有由于地表温度变化引起的基岩热膨胀效应。利用全球三维热弹性形变模型,对中国西南地区39个陆态网观测站在U、E、N三个方向的热膨胀效应进行估计,分析GNSS时间序列在热膨胀效应改正前后,与GRACE(Gravity Recovery and Climate Experiment)和GRACE Follow-On(GRACE-FO)卫星重力观测所反映地表负荷形变的符合程度。结果表明,加以热膨胀效应改正后,GNSS垂直分量(U方向)与卫星重力结果的符合程度略微减弱;而在水平分量E方向的符合程度有一定改善,但N方向出现较显著的减弱。该文得到的西南地区研究结果与已有全球或者大尺度区域的研究结果不一致,表明利用全球热弹性形变模型估计不同区域热膨胀效应的精度需要进一步评估,并且其对地表三维形变的影响也值得后续深入研究。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 thermoelastic 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.

关 键 词：热膨胀效应 地表负荷形变 GNSS GRACE GRACE-FO 

分 类 号：P312[天文地球—固体地球物理学]