Impacts of Variations in Caspian Sea Surface Area on Catchment?Scale and Large?Scale Climate

The Caspian Sea (CS) is the largest inland lake in world. Large variations sea level and surface area occurred past are projected for future. potential impacts on regional large-scale hydroclimate not well understood. Here, we examine impact of CS climate within its catchment across northern hemisphere, first time with a fully coupled model. Community Earth System Model (CESM1.2.2) used to simulate four scenarios: (a) larger than present area, (b) current (c) smaller (d) no-CS scenario. results reveal large changes atmospheric water budget. Evaporation (e) over increases increasing while precipitation (P) south-west area. P-E decreases as increases, indicating dominant negative lake-evaporation feedback. A reduces summer air temperatures winter temperatures. extend eastwards, where enhanced central Asia north-western Pacific experiences warming reduced ice. Our also indicate weakening 500-hPa troughs We find thermal response triggers southward shift upper troposphere jet stream during summer. findings establish that changing such scope should be incorporated into model simulations, including palaeo future scenarios.