Late-Glacial and Early Holocene Environmental and Climatic Change at Lake Tambichozero, Southeastern Russian Karelia

High-resolution lithostratigraphy, mineral magnetic, carbon, pollen, and macrofossil analyses, and accelerator mass spectrometry ¹⁴C measurements were performed in the study of a sediment sequence from Lake Tambichozero, southeastern Russian Karelia, to reconstruct late-glacial and early Holocene aquatic and terrestrial environmental changes. The lake formed ca. 14,000 cal yr B.P. and the area around the lake was subsequently colonized by arctic plants, forming patches of pioneer communities surrounded by areas of exposed soil. A minor rise in lake productivity and the immigration of Betula pubescens occurred ca. 11,500 cal yr B.P. The rise in summer temperatures probably led to increased melting of remnant ice and enhanced erosion. The distinct increase in lake productivity and the development of open Betula-Populus forests, which are reconstructed based on plant macrofossil remains, indicate stable soils from 10,600 cal yr B.P. onward. Pinus and Picea probably became established ca. 9900 cal yr B.P.     

Accounting for the solar radiation in thermal regime prediction for railway subgrade in cold regions

This paper presents a comparative analysis of simulation processes of seasonal freezing-thawing of railway subgrade and permafrost degradation, with and without accounting for solar radiation. Also, the effect of sun screens to reduce the degradation of subgrade permafrost under different climatic conditions is numerically substantiated. And finally, the temperature criterion of the origination of permafrost is illustrated.     

Convective structures in the Lofoten Basin based on satellite and Argo data

We discuss the possibility of detecting deep convection in the Lofoten Basin of the Norwegian Sea based on the eddy structures revealed from the satellite data. Satellite altimetry, SAR imagery, and MODIS satellite spectral radiometer sea-surface temperature (SST) data are used in the analysis, along with the data of oceanographic Argo floats. It is shown that the eddies identified from the satellite data correspond to the convective cells in the same region according to the data of the Argo floats. We consider several examples of the summer eddy and one winter eddy and the corresponding structures in the ocean measured by the Argo floats when they were located close to the identified eddies. As this method develops and improves, it can be used for the analysis of the dynamic of oceanic eddies in the region of the Lofoten Basin, and possibly in other regions with active deep convection.     

Fine spatial structure of flows on satellite radar image of the Baltic Sea

Satellite images of the sea surface demonstrate different dynamic processes at the water–air boundary and in the water layer. The objective of this investigation is to identify the fine structure of flows in the mesoscale vortex with the help of a specially developed method for flow estimation by ship wakes in the sea. The method described in this work made it possible to identify the jet nature and surges of flows in the mesoscale cyclonic vortex in the southern part of the Baltic Sea after long western and southwestern winds.     

Classification of the atmospheric droughtiness index fields in view of the modern climate change problem

In this paper, a classification of the droughtiness index fields and excessive moistening Si in the European part of Russia in May–June and July–August 1940–2000 is given. It is shown that, in May–June, the occurrence frequency of drought conditions significantly increased from the first to the second half of this period, while in July–August, the drought occurrence frequency remained almost the same.     

Space monitoring of pollution of the Russian sector of the Azov-Black Sea basin in 2008

Technology of space monitoring of the state of water bodies and results of its application for studying the Azov-Black Sea basin in 2008 are considered. Based on the processing of more than 1000 satellite images and ground-based station data, basic characteristic features of the marine environmental pollution are determined which are connected with suspension dispersion, phytoplankton and algae growth, ship dumping of oil products (more than 62 oil patches were revealed), etc. The influence of dynamic structures in the coastal zone on the spatiotemporal distribution of the sea surface pollution parameters, and their contribution to mechanisms of water purification and self-purification are estimated. In particular, new data are obtained about the evolution of “Caucasian anticyclones,” about the dates of intensification of the Main Black Sea Current, and about features of coccolithophore bloom in the abyssal area of the Black Sea, etc.     

SPECTRAL CORRELATIONS OF VEGETATION ASSOCIATIONS GROWING ON DIFFERENT GEOLOGICAL STRUCTURES

A method of correlating spectral signatures of vegetation with soil chemistry and, in turn, of inferring the presence of subsurface mineral deposits (oil in particular) is outlined. Variations in the content of nitrogen, sulfur, and trace elements in the soil, known to correspond, for example, with underground deposits of oil, induce changes in chlorophyll content of vegetation that are detectable on imagery in different zones of the spectrum, which upon statistical analysis can be used to predict the presence of oil in underlying strata. Translated from: Izvestiya vysshikh uchebnykh zavedeniy, Geodeziya i aerofotos'yemka, 1986, No. 4, pp. 88-93.     

Heat island structure over Russian towns based on mobile laboratory observations

Doklady Earth Sciences -     

Lithology,Biostratigraphy, and Geochronology of the Late Pleistocene–Holocene Sediments on the Coast of Onega Bay of the White Sea

Doklady Earth Sciences - This paper reports on the lithological, micropaleontological, and chronometric data (radiocarbon dating) for one of the areas of the White Sea coast. The sedimentary...