Analysis of the Southern Caspian Sea Level Fluctuations from GRACE Gravimetric Satellite

The Investigation of the changes in sea level, which directly affects various industries, such as shipping, fishing and power plants, is of great importance in environmental studies. As the largest enclosed water body in the world, the Caspian Sea is one of the most important water resources and has a significant impact on the environment and lives of its neighboring countries’ people. In this regard, determining variations of mass distribution of the Earth through gravimetric data can be helpful in monitoring Caspian Sea level fluctuations. Accordingly, in this study, the Caspian Sea level fluctuations from 2003 to 2017 were investigated using the Gravity Recovery and Climate Experiment (GRACE) monthly mass grids. This product includes three equivalent water thickness bands, produced by the Center for Space Research (CSR), GeoForschungsZentrum (GFZ), and Jet Propulsion Laboratory (JPL). Since, these three bands were processed independently, some differences may exist between their results, therefore, it is more reliable to consider all of them. The investigations indicated that in a point in the center of the southern Caspian Sea, the fluctuations were between -42.5 and 26 cm. In a point in the southwestern part of the study area, the fluctuations were in a range of -42.7 cm and 22.5 cm. Also, the fluctuations varied between -37.1 and 23.1 cm in a point in the southeastern part of the Caspian Sea. Furthermore, it can be inferred from our investigations that changes in water level are due to seasonal changes, climate change and irregular dam building on rivers flowing into the sea.