Studies of the European Arctic on Cruise 80 of the R/V Akademik Mstislav Keldysh

Oceanology - The multidisciplinary expedition “European Arctic-2020” on board the R/V Akademik Mstislav Keldysh took place from July 31 to August 26, 2020. The investigations were...     

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

Doklady Earth Sciences - 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...     

REE systematics in modern bottom sediments of the Caspian Sea and river deltas worldwide: Experience of comparison

The results of comparison of a number of main parameters of the chondrite-normalized REE distribution spectra in modern bottom, mainly pelitic, sediments of various sedimentary subsystems of the Caspian Sea and marginal filters of the Volga and Ural rivers with those characteristic of the pelitic fraction of modern bottom sediments of different river deltas worldwide are discussed. According to the features of the REE distribution spectra, as well as the ε_Nd(0) values, it has been established that most samples of the Caspian bottom sediments are similar to those of large rivers and rivers, draining watersheds composed of sedimentary formations.     

Distribution of Suspended Particulate Matter in the Caspian Sea

The distribution of suspended particulate matter (SPM) and chlorophyll a in the Caspian Sea water column from April to November in 2008–2016 is analyzed. It is shown that the spatiotemporal variability of SPM concentration is defined by its sources, especially by the autochthonous (primary production) and allochthonous (particulate river runoff, aerosols) components. The effect of marginal filters of rivers on the volume of coming allochthonous SPM is considered. It is revealed that chlorophyll a is a reliable marker of the autochthonous component of SPM and biogenic sedimentation conditions. The stable vertical stratification defines the distribution of allochthonous and autochthonous SPM in the water column. Vertical profiles of these SPM components in the active layer (its thickness is usually up to ~60 m, more rarely to ~100 m) of the sea are similar in April and October-November and differ much in May-September.     

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.     

Multidisciplinary experiment on studying short-period variability of the sedimentary process in the northeastern part of the Black Sea

The principal aim of this work is to reveal the regularities of short-period synoptic variability of vertical flows and the composition of settling sedimentary material, to obtain information on the quantitative characteristics of the processes that influence sound-scattering layers in the water layer above the continental slope behind the shelf edge in the northeastern part of the Black Sea. The results were obtained due to improvement of the equipment and the procedures for performing sea experiments on studying physicogeological, biological, and hydrophysical processes in the upper illuminated layer of phytoplankton development.     

Biogeochemical processes in the water column of the Caspian Sea in November 2008

Doklady Earth Sciences -     

Chemical Composition of North Atlantic Aerosols

The paper presents new information on the chemical composition of the insoluble aerosol fraction in the atmospheric surface boundary layer of different climatic zones of the North Atlantic (temperate humid, arid and semiarid, equatorial humid). The material for this study was collected during 12 expeditions. Nylon meshes were used to catch aerosols along the course of vessels. Aerosols above the North Atlantic consist of lithogenic, biogenic, and anthropogenic particles transported from different regions, which governs the differences in their concentrations and mineral and chemical compositions. Significant (by more than an order of magnitude) enrichment of aerosols in Cu, Cd, Zn, Pb, Sb, and Se is related to anthropogenic atmospheric pollution.