Vladimir Rogozhin
@ocean.ru
physics
Shirshov Institute of Oceanology of Russian Academy of sciences
I am engaged in scientific research in the field of interaction of river and sea waters; I have experience of participation in multi-day sea voyages and work with oceanographic, hydrochemical and hydrobiological equipment.
EDUCATION
Lomonosov Moscow State university, geographic faculty, department of oceanography
RESEARCH, TEACHING, or OTHER INTERESTS
Oceanography, Earth and Planetary Sciences
Scopus Publications
Scopus Publications
Alina Demkina, Darya Slonova, Viktor Mamontov, Olga Konovalova, Daria Yurikova, Vladimir Rogozhin, Vera Belova, Dmitriy Korostin, Dmitry Sutormin, Konstantin Severinov,et al.
Springer Science and Business Media LLC
AbstractMetagenomics is a powerful tool to study marine microbial communities. However, obtaining high-quality environmental DNA suitable for downstream sequencing applications is a challenging task. The quality and quantity of isolated DNA heavily depend on the choice of purification procedure and the type of sample. Selection of an appropriate DNA isolation method for a new type of material often entails a lengthy trial and error process. Further, each DNA purification approach introduces biases and thus affects the composition of the studied community. To account for these problems and biases, we systematically investigated efficiency of DNA purification from three types of samples (water, sea sediment, and digestive tract of a model invertebrate Magallana gigas) with eight commercially available DNA isolation kits. For each kit-sample combination we measured the quantity of purified DNA, extent of DNA fragmentation, the presence of PCR-inhibiting contaminants, admixture of eukaryotic DNA, alpha-diversity, and reproducibility of the resulting community composition based on 16S rRNA amplicons sequencing. Additionally, we determined a “kitome”, e.g., a set of contaminating taxa inherent for each type of purification kit used. The resulting matrix of evaluated parameters allows one to select the best DNA purification procedure for a given type of sample.
Alexander Osadchiev, Roman Sedakov, Dmitry Frey, Alexandra Gordey, Vladimir Rogozhin, Zinaida Zabudkina, Eduard Spivak, Ekaterina Kuskova, Andrey Sazhin, and Igor Semiletov
Springer Science and Business Media LLC
AbstractThe Kara Sea receives ~ 1/3 of total freshwater discharge to the Arctic Ocean, mainly from the large Ob and Yenisei rivers. The Ob-Yenisei plume covers wide area in the central part of the Kara Sea during ice-free season (June–October) and accumulates ~ 1000 km3 of freshwater volume. In late autumn, the Kara Sea becomes covered by ice, which hinders in situ measurements at this area. As a result, the fate of the Ob-Yenisei plume below sea ice during winter and spring remains unclear. In this study, we report multiple in situ measurements performed in the Kara Sea shortly before and during ice-covered season. We demonstrate that late autumn convection in the plume shortly before ice formation significantly reduces friction between the plume and the subjacent sea. The subsequent formation of solid sea ice coverage isolates the plume from wind forcing. These two factors precondition the Ob-Yenisei plume to form an intense buoyancy-driven coastal current below sea ice. As a result, the plume advects eastward to the Laptev Sea through the Vilkitsky Strait during several months in November-February. Eventually, by late winter this huge freshwater volume disappears from the Kara Sea and contributes to freshwater content of the Laptev Sea. The obtained result improves our understanding of freshwater balance of the Kara and Laptev seas, as well as provides an important insight into the large-scale freshwater transport in the Eurasian Arctic, which remain largely unknown during ice-covered season.
Alexander Osadchiev, Ivan Alfimenkov, and Vladimir Rogozhin
MDPI AG
Wind is the main external force that governs the spreading of river plumes in the sea. Many previous studies demonstrated that the spreading direction of river plumes (especially small plumes) generally coincides with wind direction. At the same time, the majority of river plumes are strongly affected by the Coriolis force, which is also among the baseline knowledge about the plumes. In this study, we focus on the deflection of plumes from wind direction induced by the Coriolis force, which received little attention before. For this purpose, we analyzed an extensive set of Landsat 8 and Sentinel-2 satellite images of multiple small- and medium-sized river plumes at different parts of the World Ocean and synchronous wind reanalysis data. We demonstrated that the deflection angle is stable for individual river plumes for different wind directions, albeit with certain limitations related to wind speed and coastal morphology. Moreover, the deflection angle is similar for river plumes located at similar latitudes and varies from ~0° near the Equator to 15–25° in temperate zones and ~30° in polar zones. Finally, we derived a direct relation between latitude and the deflection angle. The obtained results contribute to our understanding of universal features of river plume dynamics, which is important for monitoring and forecasting of delivery and fate of fluvial water and river-borne matter in different coastal regions of the World Ocean.
Anna Gebruk, Polina Dgebuadze, Vladimir Rogozhin, Yulia Ermilova, Nikolay Shabalin, and Vadim Mokievsky
Springer Science and Business Media LLC
AbstractThe Pechora Bay is a hydrologically and ecologically important area of the Barents Sea but there are still gaps in our knowledge of biodiversity of the area, including macrozoobenthos. In the first half of the twentieth century, the Pechora Bay was noted as a type locality for the bivalve mollusc Portlandia aestuariorum. Only a few surveys of macrozoobenthos have been conducted since and the last work from this area indicated the absence of P. aestuariorum. In this paper, we described macrozoobenthos and hydrological conditions of the bay based on the data collected in field campaigns in 2020–2021. All estuarine stations corresponded to a monodominant community of Macoma balthica poor in biomass (27.29 ± 20.82 g m−2) and species richness (33 species of macrozoobenthos recorded from 10 stations). The seaward most station was occupied by a marine assemblage of macrozoobenthos dominated by polychaetes Nephtys longosetosa and Cistenides hyperborea. Macrozoobenthos of the bay forms an ecocline from estuarine to marine species along the gradient of salinity. No significant differences in macrobenthic abundance, biomass and species richness were found between the 2 years of sampling and described fauna corresponds well to communities sampled in 1990s. Portlandia aestuariorum was absent in all our samples, which supports the hypothesis of disappearance of this previously common bivalve mollusc from the area, but the question of the driver of the change in macrozoobenthos remains open and requires further investigation.
Alexander Osadchiev, Zinaida Zabudkina, Vladimir Rogozhin, Dmitry Frey, Alexandra Gordey, Eduard Spivak, Anatoly Salyuk, Igor Semiletov, and Roman Sedakov
Frontiers Media SA
The major Siberian rivers form large river plumes in the Arctic Ocean, which govern structure of the sea surface layer at the Arctic shelf. These river plumes were explicitly studied during the warm period in summer and early autumn characterized by high river runoff and ice-free conditions. However, little is known about processes, which occur within these river plumes at the beginning of the cold season, i.e., during late autumn shortly before sea ice formation. In this study, we report in situ measurements performed in the Kara Sea in late October in 2020, 2021, and 2022. We reveal that intense convection occurs in the Ob-Yenisei plume due to heat loss from the surface layer, which is caused by transport of cold air from land to the central part of the Kara Sea. This process induces homogenization of the Ob-Yenisei plume and results in extremely sharp salinity jump (up to 10-12 at vertical distance of 1-2 m) between the plume and the subjacent seawater. This sharp gradient is not formed at the whole area of the plume except, first, at the Ob and Yenisei gulfs due to low surface salinities and the related high temperatures of maximal density and, second, at the lateral boundary of the plume due to intense horizontal mixing across the plume-sea border. As a result, autumn convection significantly modifies vertical structure of the Ob-Yenisei plume that could affect its further spreading below sea ice during winter season.
Vladimir Rogozhin, Alexander Osadchiev, and Olga Konovalova
Frontiers Media SA
The Pechora River forms the large Pechora River plume in the southeastern part of the Barents Sea (also called the Pechora Sea). Many previous works addressed water masses in the Barents Sea, however, the Pechora plume received relatively little attention, therefore, many basic aspects of its structure and variability remain unknown. In this study, we focus on spreading of the Pechora plume in the Pechora Sea during ice-free periods. Based on the extensive in situ measurements and satellite observations, we describe the dependence of area and spatial characteristics of the Pechora plume on wind forcing, river discharge rate, and spring ice conditions. We reveal three general types of Pechora plume spreading, which are determined by the external forcing conditions. Joint analysis of a large set of in situ and satellite data provided opportunity to study the variability of the Pechora plume on the synoptic, seasonal, and interannual time scales. We reveal regular advection of the Pechora plume through the Kara Strait into the Kara Sea. In addition, we describe formation of a significant area of increased salinity within the Pechora plume formed during wind-induced coastal upwelling events. The results of this research are of key importance for understanding the physical, biological, and geochemical processes in the Pechora Sea and the adjacent areas of the Barents and Kara seas.
Alexander Osadchiev, Alexandra Gordey, Alexandra Barymova, Roman Sedakov, Vladimir Rogozhin, Roman Zhiba, and Roman Dbar
MDPI AG
The interfaces between small river plumes and ambient seawater have extremely sharp horizontal and vertical salinity gradients, often accompanied by velocity shear. It results in formation of instabilities at the lateral borders of small plumes. In this study, we use high-resolution aerial remote sensing supported by in situ measurements to study these instabilities. We describe their spatial and temporal characteristics and then reconstruct their relation to density gradient and velocity shear. We report that Rayleigh–Taylor instabilities, with spatial scales ~5–50 m, are common features of the sharp plume-sea interfaces and their sizes are proportional to the Atwood number determined by the cross-shore density gradient. Kelvin–Helmholtz instabilities have a smaller size (~3–7 m) and are formed at the plume border in case of velocity shear >20–30 cm/s. Both instabilities induce mass transport across the plume-sea interfaces, which modifies salinity structure of the plume borders and induces lateral mixing of small river plumes. In addition, aerial observations revealed wind-driven Stokes transport across the sharp plume-sea interface, which occurs in the shallow (~2–3 cm) surface layer. This process limitedly affects salinity structure and mixing at the plume border, however, it could be an important issue for the spread of river-borne floating particles in the ocean.
Publications
Rogozhin, V. and Osadchiev, A., 2022, May. Spreading of the Pechora river plume in the southeastern part of the Barents Sea in 2017-2021. In EGU General Assembly Conference Abstracts (pp. EGU22-7299).
Rogozhin, V., Polukhin, A., Yakushev, E., and Semiletov, I.: Features of the Lena River runoff influence on the adjacent Laptev Sea shelf, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14630, , 2021.
Рогожин В.С., Полухин А.А., Якушев Е.В. , Семилетов И.П. . ВЛИЯНИЕ СТОКА РЕКИ ЛЕНА НА ГИДРОХИМИЧЕСКУЮ СТРУКТУРУ ВОД ЦЕНТРАЛЬНОЙ ЧАСТИ МОРЯ ЛАПТЕВЫХ В ЛЕТНИЙ СЕЗОН В 2019 ГОДУ // Комплексные исследования Мирового океана. Материалы VI Всероссийской научной конференции молодых ученых, г. Москва, 18–24 апреля 2021 г. Москва: Институт океанологии им. П. П. Ширшова РАН, 2021, С. ***–***, DOI:10.29006/978-5-6045110-3-91.
Рогожин В.С., Дианский Н.А., Полухин А.А. ДИНАМИЧЕСКИЕ ХАРАКТЕРИСТИКИ ЛИНЗЫ РАСПРЕСНЕННЫХ ВОД В 2015 ГОДУ. Труды VIII Международной научно-практической конференции «Морские исследования и образование (MARESEDU-2019)» Том I (III): [сборник]. Тверь: ООО «ПолиПРЕСС», 2020,296 с.: ISBN 978-5-6042986-0-2.
Рогожин В.С.., Полухин А.А. Влияние стока реки Лена на гидролого-гидрохимическую структуру моря Лаптевых в летний сезон: Труды IX Международной научно-практической конференции «Морские исследования и образование (MARESEDU-2020)» Том I (III): [сборник]. Тверь: ООО «ПолиПРЕСС», 2020, 362 с.: ISBN 978-5-6045536-3-3.