The late Holocene climatic events on the southernmost Russian far east coast: variability drivers

Hydroclimatic changes along the southernmost coast of the Russian Far East, as reconstructed over the past 2460 years, were primarily driven by the intensity of monsoon circulation that was strongly influenced by solar activity and processes in the low-latitude Pacific. An analysis of ecological indicators of Lotus Lake environment (diatoms, botanical composition, mineral content) revealed periods of increased and decreased lake level that corresponded to strengthening and weakening of the summer monsoon. Lotus Lake experienced six stages of increasing and decreasing of lake watering. The basin originated as a meso-eutrophic lake connected to the sea. The connection between the lake and the sea was interrupted ~2100 yr BP, which caused a change in the geochemical environment. To understand hydroclimate changes, data on surface temperature anomalies in the western tropical Pacific Ocean were used. These anomalies were strongly influenced by El Niño. Changes in the intensity of the warm Kuroshio Current were one of the factors that influenced precipitation. A comparison of regional data showed spatial heterogeneity in the moisture distribution, which was associated with changes in typhoon tracks during the Late Holocene. The paleoclimatic situation on the southernmost coast of the Russian Far East, which experienced a relatively dry Medieval Climate Anomaly and a wet Little Ice Age, was similar to that of Korea. A sharp decrease in lake depth and swamping of the shores occurred at two periods: at the beginning of global cooling (1650–1600 yr BP), and 1230 yr BP, when there was a slight cooling trend and El Niño activation. The greatest variability in environments occurred during the last millennium. There were frequent and abrupt climatic variations, particularly during the Little Ice Age. Evidence of temperature and hydrological changes was obtained for the solar minima; the swamp wetness around Lotus Lake decreased.