Two late Holocene cold events were described for the Southern Russian Far East: 2800–2600 year BP and the Little Ice Age (LIA) (~1300–1850 CE). The synthesis is based on multi-proxy records on profile “the mainland (Primorye)-islands (Sakhalin-Kurils)”. Main archives are sediments of small lakes and peat bogs that recorded the high-resolution environmental changes. The temporal resolution of reconstructions here is up to 26–40 years. During the cold event of 2800–2600 year BP, the humidity decreased sharply, there were long-term dry seasons without strong floods, and buried soil formed on floodplains. The LIA was wet in the mainland and the Kurils, with frequent strong floods, but was drier in Sakhalin. The cooling was characterized by sharp temperature fluctuations where high moisture conditions alternated with short-term drier periods. The shift in geographical position and intensity of the main centers of atmospheric action caused a paleoclimatic interpretation of these events (Aleutian Low, Siberian and North Pacific Highs, the summer Okhotsk anticyclone and the Far East depression). Changes in the North Pacific oscillations played an important role in the alternation of cold-dry and cold-wet periods. Anomalies in the intensity of El Niño and the monsoon system led to changes in tropical and extratropical cyclone trajectories and cyclogenesis in general.

A continuous record of paleogeographic events in the Shantar islands since the end of the Pleistocene has been obtained by a multy-proxy study of the stratigraphy of the blanket peatland. The biostratigraphical studies included botanical, diatom, and pollen analyses. The age-depth model has been developed using seven radiocarbon dates. Data on the development of the environment have been obtained for the first time in the coldest part of the Sea of Okhotsk. The paleoclimatic events were synchronous and metachronous with the regional data and the global changes. The Younger Dryas was much colder in the Shantar islands than in other areas around the Sea of Okhotsk. The climate became more marine after isolation of the islands in the early–middle Holocene. The cold sea and the drifting ice were among the major factors that resulted in the poorly defined early and middle Holocene optimums in this area and in the characteristics of the climatic rhythm. Models have been proposed to explain the alternation of relatively warm and cold periods with different humidity. The age of periods of heavy snowfall, as shown by changes in the role of dwarf pine in the island vegetation, has been estimated. The local swamp and zonal landscape phases have been highlighted. Spruce appeared in this area ~11 410–10 345 cal yr BP, when a landbridge existed; spruce trees became common in the middle Holocene, especially at the turn of the middle–late Holocene. The thermokarst processes were one of the controlling factors of swamp landscapes. The environment underwent major changes in the Little Ice Age; the most severe conditions occurred ~500–260 cal yr BP. In the most-recent 210 years, the most considerable changes in landscapes were related to fires of a human origin.

Allochthonous biofossil distribution in the blanket peat bog of Bolshoy Shantar Island was used to analyze atmospheric circulation anomalies in the north-western Okhotsk Sea over the last 12.6 ka. The main aim of this study was to determine periods of intensification of deep cyclones and extreme storms. The composition of bioaerosols is significantly influenced by atmospheric zonal and meridional transport anomalies associated with anomalies of the monsoon system of Northeast Asia, atmospheric fronts and cyclone trajectories. Marine diatoms enter the peatland from the sea during extreme storms and record the passage of sea cyclones in the autumn-winter, whereas the distribution of allochthonous pollen indicates the intensity of continental cyclones. We used Pinus pumila pollen as an indicator of heavy snowfalls and winter cyclone activity. Fifteen phases of extreme storms were identified. Changes in ice coverage also played an important role in bioaerosol emission. During cold periods, emissions of bioaerosols mainly occurred in the open sea, whereas during warm periods, emissions occurred near the coast. The recurrence and intensity of cyclones during the cold seasons depends on displacement of the Siberian High and Aleutian Low. Periods of continental cyclones intensified in spring-summer and coincided with periods of active winter cyclogenesis.