联合时变重力数据与测高数据反演全球海平面变化及其分量贡献

理解全球海平面变化具有十分重要的意义,它间接反映了地球系统中气候性相关因素的变化。本文基于一组海平面指纹和比容经验正交函数,联合时变重力数据和卫星测高数据反演了2002年4月至2020年2月的全球海平面变化,将全球海平面变化分解成南极冰盖融化、格陵兰冰盖融化、陆地冰川融化、陆地水储量变化、冰川均衡调整和海水比容效应这6个分量的贡献。联合反演结果显示,全球平均比容海平面变化为1.08±0.05 mm/a,与相关文献的结果相吻合。研究发现,联合测高数据和时变重力数据的反演方法能够一定程度上减弱GRACE Follow-On卫星时期海水质量变化被低估的现象。本文利用联合反演的结果研究了区域海平面变化,在大部分近海区域反演效果较好,这表明该方法可用于区域海平面变化的研究。

Inversion of global sea level change and its component contributions by combining time-varying gravity data and altimetry data

Understanding sea level change is of paramount importance,it indirectly reflects the changes of climate-related factors in earth system.Based on a set of sea level fingerprints and steric empirical orthogonal functions,a joint inversion is applied by combining time-varying gravity data and satellite altimetry data to derive global sea level change from April 2002 to February 2020.In this research,global sea level change was divided into the contributions of polar ice sheets melting,terrestrial glaciers melting,terrestrial water storage change,glacial isostatic adjustment and steric effect.Joint inversion result shows that global mean steric sea level change is 1.08±0.05 mm/a,which is consistent with the results of relevant literature.It was found that the joint inversion which combined altimetry and time-varying gravity data could reduce the underestimation of global mean ocean mass change during GRACE Follow-On period.Regional sea level changes were investigated by joint inversion,in most coastal areas,inversion results are good of quality,which shows that this method can be used to study regional sea level change.