Investigation of mass changes with GRACE and GRACE-FO satellite

The Gravity Recovery and Climate Experiment-Follow-On (GRACE-FO) satellite is a continuation of the GRACE satellite mission in 2018. GRACE-FO provides relevant information about the water cycle and TWS. Based on GRACE-FO observations, mass changes can be studied temporarily. Greenland, South Africa, Antarctica, parts of Alaska and Bangladesh have a lot of mass loss. In the Middle East, Saudi Arabia and the Caspian Sea also mass loss on average between mid-2019 and mid-2020. The Caspian Sea is bordered by Iran, Russia to the north, Russia and the Republic of Azerbaijan to the west, and the Republics of Turkmenistan and Kazakhstan to the east. The northern part of the Caspian Sea is very shallow. Caspian Sea Level (CSL) has been declining in recent years. In this research, gravimetric satellites have been investigated for CSL. The rate of decrease of the Caspian Sea is 3.87 cm/year. The results also show that the decrease in CSL in the north compared to the center and south is almost half, which needs further investigation.