The head of the project: Andrey L. Zakharov
The title of the project: Geological and geomorphological indicators of changes in atmospheric circulation in the Azov-Ciscaucasian region over the past 150 thousand years
Key words: aeolian processes, deflation, accumulation, dust, paleoclimate, atmospheric circulation reconstruction, loess, paleo-soil, Pleistocene, Holocene, climatic modeling
The Azov-Ciscaucasian region is an arena of intensive eolian processes. Eolian denudation, as well as accumulation, led to the emergence of a complex of geomorphological and sedimentological phenomena here. These include the large-flatbottom relief of the western and central Ciscaucasia, the linearly oriented ridges of the eastern Ciscaucasia, dune fields and ridge sands of the western part of the Caspian lowland, as well as the most thick loess cover in Europe (up to 140 m). The combination of all the above manifestations of aeolian processes can be used as a basis, a set of numerous indicators for the reconstruction of the history of accumulative and denudation aeolian events of the past, including extreme ones. This will allow us to understand the variability of atmospheric circulation. Within the framework of the proposed project, a complex of geological and geomorphological studies is planned, aimed at: 1) determining the pattern of distribution, thickness and composition of loess deposits of the Upper Pleistocene; 2) identification of the mechanisms of formation and age of poorly studied (potentially aeolian) complexes of the relief of the Azov-Ciscaucasian region: the large-flatbottom relief of the Azov and Plains of the Central Ciscaucasia, linearly oriented ridges in the loess plains of the eastern Ciscaucasia. The solution of these problems will allow us to approach the determination of the prevailing directions of eolian transfer and the rate of accumulation of dust for individual chrono-cuts of the late Pleistocene. The obtained results are planned to be compared with the data of paleoclimatic modeling (model of the PMIP project), and to draw conclusions about the quality of reproduction by atmospheric circulation models at the scale of the study region. The relevance of this study is determined by the fundamental importance for solving the problems of regional geomorphology, paleogeography and climatology, as well as an applied value in the field of forecasting extreme aeolian processes in the long-medium term.
The expected results
1. Determination of the mechanisms and age of the formation of poorly studied (potentially aeolian) complexes of the relief form of the Azov-Ciscaucasian region: 1) large-flatbottom relief of the Azov and Central Ciscaurian plains, 2) linearly oriented ridges in the loess plains of the eastern Ciscaucasia . Obtaining this result will make a significant contribution to regional geomorphology, will allow to evaluate the role of aeolian processes in the formation of the relief of loess plains. The large-flatbottom relief of the plains of the Azov region and the central Ciscaucasia is unique in its kind and has no direct analogues in other loess regions of the world, which increases the scientific significance of its study.
2. Identification of spatial patterns of changes in the thickness and composition of the Upper Pleistocene loess of the Azov-Ciscaucasian region; explanation of the reasons for the heterogeneity of the loess cover; determination of sources, prevailing directions and rates of eolian dust transport for separate stages of the Late Pleistocene and Holocene.The solution of this problem will allow to determine the main directions of the aeolian transfer and the sources of dust supply to the plains of the Pre-Caucasus and the Azov region in the Late Pleistocene and Holocene. Based on this result, it will be possible to reconstruct the direction and strength of the aeolian streams for individual time slices.
3. Assignment of the stages of activation and weakening of eolian processes over the past 150 thousand years based on the analysis of relict aeolian relief and sedimentary paleoarchives (loess and lake sediments).
4. Reconstruction of the general scheme (direction and speed) of surface air flows for climate extremes over the past 150 thousand years. The systemic reconstruction of the atmospheric circulation for the Azov-Ciscaucasian region for the last 150 thousand years based on geomorphological and sedimentological indicators has not been carried out previously. Obtaining this result will make a significant contribution to the paleogeography of the south of the East European Plain. The stated result is fully consistent with the world level of research in this field of science, as evidenced by the analysis of the literature.
5. Verification of paleoclimatic models of the PMIP project on the basis of newly obtained regional data on atmospheric circulation for the last millennium, Holocene optimum (6 ky ago), last glacial maximum (21 ky ago) and interglacial (127 ky ago).For the first time, verification of the PMIP paleoclimatic models for the Azov-Ciscaucasian region based on paleocirculatory reconstructions using geomorphological and sedimentological indicators will be performed.
6. Explanation of the causes of changes in the atmospheric circulation in the region in the context of the global climate rhythm. Assessment of possible transformations in the atmospheric circulation and the development of eolian processes in the region against the background of expected climate changes in the 21st century. This result will be the basis for creating a scientifically based forecast of the development of eolian processes in the Azov-Ciscaucasian region in the 21st century, which is extremely important for the population and the economy of the region.