Present-day variations and paleodynamics of the Caspian Sea level as a standard for climate modeling data verification

Long-term variations of the Caspian Sea level occur mainly due to river runoff variations (the variations of the Volga River runoff is of primary importance here). In this case, the observed and reconstructed variations of the Caspian Sea level can serve as a standard for assessing the quality of the model runoff simulated by climate models. To solve this problem, a number of detailed maps of the Caspian Sea are prepared for the series of regression and transgression stages. These data are used for verifying the results of some numerical experiments carried out within the framework of CMIP5/PMIP3. It is demonstrated that the model data can be verified depending on how well the models simulate the present-day (instrumentally observed) variations of the decadal scale reconstructed in recent 1000 years of variations: the transition from the Derbent regression to the New Caspian transgression (the 5th phase) with the insignificant sea level drop in the late 19th century and under conditions of large regression during the period of the late Pleistocene glaciation maximum.     

Reconstruction of Late Pleistocene events in the periglacial area in the southern part of the East European Plain

An integrated study of the loess–soil sequence in the coastal exposure near the settlement of Beglitsa (Rostov oblast) allowed us, for the first time, to reconstruct the landscape-climatic changes that occurred in the eastern Azov region over the course of the Late Pleistocene. In the south of the periglacial zone, considerable differences between intensity of the loess accumulation in the Early and Late Valdai Cryochrons were revealed. In the Early Valdai Epoch, which corresponds roughly to the end of Marine Isotope Stage (MIS) 5 and MIS 4, loess accumulation occurred after completion of development of the Mezin pedocomplex and before the beginning of the Bryansk stage of soil development, i.e., over more than 20 000 years. In the much shorter Late Valdai Cryochron MIS 2 (10 000–12 000 years), loess accumulation reached 5 m. The data evaluation shows that the loess accumulation rates in the Early Valdai Epoch (~0.07 mm/year) and the Late Valdai Epoch (~0.5 mm/year) differ from each other by an order of magnitude.