A. P. Lisitzin

Elemental and Organic Carbon in Atmospheric Aerosols over the Northwestern Coast of Kandalaksha Bay of the White Sea

This report presents data on the distribution of elemental and organic carbon in the surface layer of the atmosphere on the northwestern coast of Kandalaksha Bay of the White Sea for the years 2010–2012. Elemental carbon (EC) is the primary component of black carbon, which has made a considerable contribution to climate change in the Arctic region. The concentrations of EC are at the background level for the Arctic and are characterized by minor seasonal and annual variability. A significant source of EC is the western transfer from the direction of industrial regions of Northern Europe, including the gas flares of the oil fields in the North Sea. Forest fires during summer months are additional sources of EC.

Distribution and composition of suspended particulate matter in the Atlantic Ocean: Direct measurements and satellite data

The main purpose of this work is to study the real distribution and spatial–temporal variations of suspended particulate matter and its main components in surface waters of the Atlantic Ocean on the basis of direct and satellite measurements for development of new and perfection of available algorithms for converting satellite data. The distribution fields of suspended particulate matter were calculated and plotted for the entire Atlantic Ocean. It is established that its distribution in the open ocean is subordinate to the latitudinal climatic zonality. The areas with maximum concentrations form latitudinal belts corresponding to high-productivity eutrophic and mesotrophic waters of the northern and southern temperate humid belts and with the equatorial humid zone. Phytoplankton, the productivity of which depends primarily on the climatic zonality, is the main producer of suspended particulate matter in the surface water layer.

Seasonal variation of fluxes of dispersed sedimentary matter in the White Sea (Arctic ocean basin)

The monthly and seasonal quantity estimates of vertical fluxes of sedimentary matter from the White Sea performed during studies are the basis for the direct calculations of incoming chemical components, minerals, and various pollutants to the surface layer of bottom sediments. The White Sea, one of six Russian Arctic seas, may be considered as a megapolygon for further modern research using the new regularities of arctic sedimentogenesis established. This study focuses on the development of new technologies for complex studies of marine water areas using underwater sedimentation observatories, regular observations onboard vessels, and satellite oceanological data. The first priority task is year-round monitoring along the Northern Sea Route.

Oxygen isotope and deuterium composition of snow cover on the profile of Western Siberia from Tomsk to the Gulf of Ob

The purpose of this work is to study the variability of the isotope composition (δ18О, δD, dexc) of the snow cover on a long transect of Western Siberia from the southern taiga to the tundra. The study of the snow cover is of paleogeographic, paleogeocryological, and paleohydrological value. The snow cover of western Siberia was sampled on a broadly NS transzonal profile from the environs of Tomsk (southern taiga zone) to the eastern coast of the Gulf of Ob (tundra zone) from February 19 to March 4, 2014. Snow samples were collected at 31 sites. Most of the samples represented by fresh snow, i.e., snow that had fallen a day before the moment of sampling were collected in two areas. In the area of Yamburg, the snow specimens collected from the surface are most probably settled snow of different ages. The values of δ18О in the snow from Tomsk to Yamburg varied from–21.89 to–32.82‰, and the values of δD, from–163.3 to–261.2‰. The value of deuterium excess was in the range of 4.06–19.53‰.

Chlorophyll a in suspended particulate matter of the Caspian Sea as an indicator of biogenic sedimentation conditions

The conditions of biogenic sedimentation (concentration of chlorophyll a (chl a), particulate organic carbon (POC), and its isotope composition (δ13СPOC)), as well as the quantitative characteristics of phytoplankton, and the total concentration of suspended particulate matter have been studied in the Caspian Sea in May and June 2012. The vertical (from the surface layer to bottom) distribution and precipitation of the biogenic component of suspended particulate matter have been determined. It was found that only 5% of the particulate matter and around 3% of POC reached the Middle Caspian after passing through a marginal filter (Volga River delta–Northern Caspian). The subsurface chl a maximum layer (around 20–60 m) with a cold-water phytoplankton community was revealed in the Middle and Southern Caspian. The subsurface region of accumulation of chl a and phytoplankton in the subthermocline layer has been extended from the southern periphery of the Derbent Depression to the Absheron Sill.

The phenomenon of bloom development of the invasive potentially toxic dinoflagellate Gonyaulax polygramma in deep water areas of the Caspian Sea

This work presents the first data on the occurrence of the invasive, potentially toxic dinoflagellate Gonyaulax polygramma in the composition of plankton phytocenoses in the Caspian Sea. It was revealed that G. polygramma plays the key role in the quantitative characteristics of summer plankton phytocenoses and its bloom during the summer seasons of 2010 and 2013 was comparable in biomass (15–16 g/m3) to a “red tide.” In addition, the correlation between the G. polygramma bloom and the wind upwelling system in the eastern mid-Caspian region was established. For the first time, it is suggested that “bloom” of G. polygramma can also occur in deep-water halistatic areas (Derbent depression), remote from the upwelling system.

Dynamics of the main components of fluxes of sedimentary matter in the White Sea

The results of long-term investigations in a small sea of the Arctic Ocean served as a basis for revealing new regularities characteristic of the sedimentary process in the Subarctic and Arctic zones. The monthly, seasonal, and multiyear dynamics of the main components of dispersed sedimentary matter fluxes are analyzed by defining the marine sedimentation stage. It is shown that the biogenic constituent of the flux decreases by an order of magnitude at its transition from dispersed to concentrated forms. The average values of the vertical flux are calculated including the total sedimentary matter and the contribution of main biogenic and terrigenous components per m2 of the bottom and the entire deep area of the White Sea.

Diatoms and aquatic palynomorphs in surface sediments of the White Sea bays as indicators of sedimentation in marginal filters of rivers

Diatom algae, aquatic palynomorphs, and the grain-size of surface sediments from bays of the White Sea were investigated in a program dedicated to the study of marginal filters (MF) in the Severnaya Dvina, Onega, and Kem rivers. Three microalgal assemblages are established in surface sediments, which replace each other successively with distance from river mouths and are characterized by a gradual decrease in a share of freshwater species of diatoms and Chlorophyceae algae, significantly varying concentrations of marine diatoms and dinocysts due to changes in water salinity, grain-size composition of sediments, quantitative distribution of suspended particulate matter (SPM), and water productivity at different marginal filter stages.

First results on determination of chlorophill A and its derivatives in the system of trapped sedimentary material–fluffy layer–bottom sediment of the Caspian Sea

The first data were obtained on the vertical chlorin flux in the water column and its accumulation in the upper layer of sediments of the Caspian Sea. Seasonal variability of the chlorine concentration in sedimentary matter was evaluated. The tendency of decrease in the phytoplankton-synthesized (allochtonous) organic matter content was revealed over approximately the past 60 years.

Geochemical anomalies in South Caspian sediments

Study of the element composition of ten samples of modern terrigenous and carbonate sediments from the northern part of the Caspian Sea by the ICP-MS method showed that these sediments were enriched in sulfur, nonferrous metals, and some related minor elements including Se, Te, Re, and others in comparison with the average composition of sedimentary rocks. It is assumed that local hydrothermal seeps similar to those known on the Cheleken Peninsula and which may be formed in other areas of this tectonically active zone are the sources of these elements. In addition, such a composition of sediments may indicate the sporadic contamination of bottom water with hydrogen sulfide, which has been observed in areas of the South and Middle Caspian by many researchers.