Abstract
<jats:p>The article presents the results of a study of the impact of climate change and large-scale atmospheric circulation processes on the level regime of the southern Caspian Sea. Based on an analysis of data from meteorological stations in Iran and Turkmenistan for the period 1961–2024, stable trends in air temperature increase and water balance transformation in the region have been identified. Particular attention is paid to the correlation analysis of the relationship between sea level and circulation patterns according to the Wangenheim-Girs classification and the North Atlantic Oscillation (NAO) index. It has been established that the dominant predictor of transgressive sea level phases is the western circulation type (W), while the eastern type (E) is a key factor in regressions. A pronounced seasonal determination of these relationships has been identified, with maximum intensity in the winter period. The results of the study are of practical importance for forecasting hydrological risks and developing adaptation strategies in the coastal areas of Iran and Turkmenistan.</jats:p>