Dynamics of microalgae development in the under-ice period in Southern Baikal

2019 ◽  
pp. 39-44
Author(s):  
Maria V. Bashenkhaeva ◽  
Yulia R. Zakharova ◽  
Yelena V. Likhoshway
Keyword(s):  
Lake Baikal ◽  
Ecological Zones ◽  
Spring Peak ◽  
Ice Water ◽  
Ice Period ◽  
South Baikal

Spring peak of phytoplankton vegetation in Lake Baikal starts in under-ice period. This article presents the results of a study of the microalgae composition at the “ice – water” phases in different ecological zones in South Baikal over five years.

scholarly journals Movements activity of the Baikal seal according to satellite tagging data

Trudy VNIRO ◽  
2020 ◽  
Vol 181 ◽  
pp. 92-101
Author(s):  
M.A. Solovyeva ◽  
◽  
G.U. Pilipenko ◽  
D.M. Glazov ◽  
V.A. Peterfeld ◽  
...  
Keyword(s):  
Lake Baikal ◽  
Satellite Telemetry ◽  
Sharp Decline ◽  
Period Data ◽  
Males And Females ◽  
Satellite Tagging ◽  
Ice Period ◽  
Observation Period

In this article presented new data about movements activity of the Baikal seal (Pusa sibirica) — endemic of the Lake Baikal, obtained using satellite telemetry from July 2019 to March 2020. The average distances during the day was 9.9 ± 2.7 SE km for females, 17.0 ± 2.1 km for males, range of movements during the observation period was up to 5459 km for females and up to 8220 km for males. The most active movements occurred in August and December for males and in November for females. In October, males and females moved the least actively, which may be associated with their movement to shallow, rapidly freezing bays and sores. A sharp decline in activity also took place in January-February, when seals probably began a “settlement” ice period. Data consistent with previous tagging of subadult Baikal seals in 1990–1991. We obtained lower values of covered distances and average indicators for the month for females compared to males. However, we not found statistically significant differences between males and females, and question of differences in movement between subadult males and females still open.

A new similarity model for the stratified under-ice boundary layer in lakes and its application to ice-covered Lake Baikal

2020 ◽  
Author(s):  
Georgiy Kirillin ◽  
Ilya Aslamov ◽  
Nikolai Granin ◽  
Roman Zdorovennov
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Lake Baikal ◽  
Strong Dependence ◽  
Shear Velocity ◽  
Ice Cover ◽  
Heat Fluxes ◽  
Solid Boundary ◽  
Buoyancy Frequency ◽  
Ice Water

<p>Seasonal ice cover on lakes and polar seas creates seasonally developing boundary layer at the ice base with specific features: fixed temperature at the solid boundary and stable density stratification beneath. Turbulent transport in the boundary layer determines the ice growth and melting conditions at the ice-water interface, especially in large lakes and marginal seas, where large-scale water circulation can produce highly variable mixing conditions. Since the boundary mixing under ice is difficult to measure, existing models of ice cover dynamics usually neglect or parameterize it in a very simplistic form. We propose a model of the turbulent energy budget in the stably stratified boundary layer under ice, based on the length scale incorporating the dissipation rate and the buoyancy frequency (Dougherty-Ozmidov scaling). The model was verified on fine-scale measurements in Lake Baikal and demonstrated a good agreement with data. The measured ice-water heat fluxes in were among the largest reported in lakes (up to 40 W m<sup>−2</sup>) and scaled well against the proposed relationship. The model yields a scaling relationship for the ice-water heat flux as a function of the shear velocity squared that suggests the traditional bulk parameterizations may significantly underestimate the ice-water heat flux, especially at strong under-ice current velocities. The ultimate result consists in a strong dependence of the water-ice heat flux on the shear velocity under ice. </p>

Natural infection of the calanoid crustacean Epischura baicalensis by procercoids of Proteocephalus sp. in Listvenichnyi Bay, Lake Baikal

1996 ◽  
Vol 70 (3) ◽  
pp. 237-247 ◽  
Author(s):  
O.T. Rusinek ◽  
M.P. Bakina ◽  
A.V. Nikolskii
Keyword(s):  
Lake Baikal ◽  
Natural Infection ◽  
The Third ◽  
Summer Generation ◽  
Copepodid Stage ◽  
One Year ◽  
South Baikal

AbstractNatural infection of the plankton Epischura baicalensis Sars (Calanoida: Temoridae) by procercoids of the genus Proteocephalus in Lake Baikal is analysed in detail. Over one year Epischura was infected by procercoids of proteocephalids at a prevalence of 0.13% (in Listvenichnyi Bay, South Baikal). Male E. baicalensis were infected more (0.39%). The number of procercoids of genus Proteocephalus was 2.7 specimens/m3. The largest number of procercoids was found in females (1.26), the least in the third copepodid stage (0.03 specimens/m3). Because of the close ecological contacts between E. baicalensis and Coregonus autumnalis migratorius it is probable that E. baicalensis is infected by P. exiguus, the species usually found in C. a. migratorius (Zaika, 1965). The parasite lives for about 8 months in the winter-spring Epischura generation and about 10 months in the summer generation.

scholarly journals Interconnection of bacterial and phytoplanktonic communities with hydrochemical parameters from ice and under-ice water in coastal zone of Lake Baikal

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yu. S. Bukin ◽  
N. A. Bondarenko ◽  
I. I. Rusanov ◽  
N. V. Pimenov ◽  
S. V. Bukin ◽  
...  
Keyword(s):  
Coastal Zone ◽  
Lake Baikal ◽  
Hydrochemical Parameters ◽  
Ice Water

scholarly journals Turbulence in the stratified boundary layer under ice: observations from Lake Baikal and a new similarity model

2020 ◽  
Vol 24 (4) ◽  
pp. 1691-1708 ◽  
Author(s):  
Georgiy Kirillin ◽  
Ilya Aslamov ◽  
Vladimir Kozlov ◽  
Roman Zdorovennov ◽  
Nikolai Granin
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Lake Baikal ◽  
Dissipation Rate ◽  
Large Scale ◽  
Shear Velocity ◽  
Ice Cover ◽  
Solid Boundary ◽  
Buoyancy Frequency ◽  
Ice Water

Abstract. Seasonal ice cover on lakes and polar seas creates seasonally developing boundary layer at the ice base with specific features: fixed temperature at the solid boundary and stable density stratification beneath. Turbulent transport in the boundary layer determines the ice growth and melting conditions at the ice–water interface, especially in large lakes and marginal seas, where large-scale water circulation can produce highly variable mixing conditions. Since the boundary mixing under ice is difficult to measure, existing models of ice cover dynamics usually neglect or parameterize it in a very simplistic form. We present the first detailed observations on mixing under ice of Lake Baikal, obtained with the help of advanced acoustic methods. The dissipation rate of the turbulent kinetic energy (TKE) was derived from correlations (structure functions) of current velocities within the boundary layer. The range of the dissipation rate variability covered 2 orders of magnitude, demonstrating strongly turbulent conditions. Intensity of mixing was closely connected to the mean speeds of the large-scale under-ice currents. Mixing developed on the background of stable density (temperature) stratification, which affected the vertical structure of the boundary layer. To account for stratification effects, we propose a model of the turbulent energy budget based on the length scale incorporating the dissipation rate and the buoyancy frequency (Dougherty–Ozmidov scaling). The model agrees well with the observations and yields a scaling relationship for the ice–water heat flux as a function of the shear velocity squared. The ice–water heat fluxes in the field were the largest among all reported in lakes (up to 40 W m−2) and scaled well against the proposed relationship. The ultimate finding is that of a strong dependence of the water–ice heat flux on the shear velocity under ice. The result suggests large errors in the heat flux estimations when the traditional “bulk” approach is applied to stratified boundary layers. It also implies that under-ice currents may have much stronger effect on the ice melt than estimated by traditional models.

Estimate of heat flux at the ice-water interface in Lake Baikal from experimental data

2014 ◽  
Vol 457 (2) ◽  
pp. 982-985 ◽  
Author(s):  
I. A. Aslamov ◽  
V. V. Kozlov ◽  
I. B. Misandrontsev ◽  
K. M. Kucher ◽  
N. G. Granin
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
Lake Baikal ◽  
Water Interface ◽  
Ice Water

scholarly journals Turbulence in the stratified boundary layer under ice: observations from Lake Baikal and a new similarity model

2019 ◽  
Author(s):  
Georgiy Kirillin ◽  
Ilya Aslamov ◽  
Vladimir Kozlov ◽  
Roman Zdorovennov ◽  
Nikolai Granin
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Lake Baikal ◽  
Dissipation Rate ◽  
Strong Dependence ◽  
Shear Velocity ◽  
Ice Cover ◽  
Solid Boundary ◽  
Buoyancy Frequency ◽  
Ice Water

Abstract. Seasonal ice cover on lakes and polar seas creates seasonally developing boundary layer at the ice base with specific features: fixed temperature at the solid boundary and stable density stratification beneath. Turbulent transport in the boundary layer determines the ice growth and melting conditions at the ice-water interface, especially in large lakes and marginal seas, where large-scale water circulation can produce highly variable mixing conditions. Since the boundary mixing under ice is difficult to measure, existing models of ice cover dynamics usually neglect or parameterize it in a very simplistic form. We present first detailed observations on mixing under ice of Lake Baikal, obtained with the help of advanced acoustic methods. The dissipation rate of the turbulent kinetic energy (TKE) was derived from correlations (structure functions) of current velocities within the boundary layer. The range of the dissipation rate variability covered 2 orders of magnitude, demonstrating strongly turbulent conditions. Intensity of mixing was closely connected to the mean speeds of the under-ice currents, the latter being of geostrophic origin and having lake-wide scales. Mixing developed on the background of stable density (temperature) stratification, which affected the vertical structure of the boundary layer. To account for stratification effects, we propose a model of the turbulent energy budget based on the length scale incorporating the dissipation rate and the buoyancy frequency (Dougherty-Ozmidov scaling). The model agrees well with the observations and yields a scaling relationship for the ice-water heat flux as a function of the shear velocity squared. The ice-water heat fluxes in the field were the largest among all reported in lakes (up to 40 W m−2) and scaled well against the proposed relationship. The ultimate result consists in a strong dependence of the water-ice heat flux on the shear velocity under ice. The result suggests large errors in the heat flux estimations, when the traditional bulk approach is applied to stratified boundary layers. It also implies that under-ice currents may have much stronger effect on the ice melt than estimated by traditional models.

scholarly journals Some Results of Digital (in situ) Monitoring of Atmospheric Pollution with Gaseous Impurities in the Central Ecological Zone of South Baikal

2020 ◽  
Vol 34 ◽  
pp. 141-155
Author(s):  
T. V. Khodzher ◽  
◽  
V. A. Obolkin ◽  
E. V. Molozhnikova ◽  
M. Yu. Shikhovtsev ◽  
...  
Keyword(s):  
High Resolution ◽  
Lake Baikal ◽  
Atmospheric Pollution ◽  
Temporal Variability ◽  
Thermal Power ◽  
In Situ Monitoring ◽  
Common Source ◽  
Ecological Zone ◽  
Synoptic Conditions ◽  
South Baikal

The article presents the results of continuous automatic monitoring of atmospheric transport of pollutants in the source area of the Angara river (South Baikal) at the "Listvyanka" atmospheric monitoring station in 2019-2020. The temporal variability of the concentrations of oxides of sulfur, nitrogen, and mercury in the atmosphere of the сentral ecological zone of the lake Baikal is analyzed with high resolution from minutes to days. The use of automatic high-resolution gas analyzers for atmospheric impurities and meteorological parameters allows real-time monitoring of the flow of atmospheric pollution into the сentral ecological zone of South Baikal. Depending on the meteorological and synoptic conditions, observations demonstrate a high variability in the concentrations of anthropogenic impurities in the atmosphere over South Baikal. It is shown that the most severe atmospheric pollution occurs during the transfer of air masses from the north-northwest in winter. When transported from the South Baikal, atmospheric pollution is minimal. The temporal variability of the concentrations of the studied impurities occurs synchronously, which indicates their common source of origin – the combustion of fossil fuel. The highest time fluctuations are determined for the concentrations of sulfur and nitrogen oxides, the fluctuations in mercury concentrations are less significant. The average (median) and maximum (one-time) concentrations of sulfur oxides at "Listvyanka" station are given, depending on the prevailing wind directions. Direct trajectories of air mass transfer from the source cities of the Irkutsk region (Irkutsk, Angarsk, Shelekhov) are presented. At the time of the increase in the concentration of gas impurities at the "Listvyanka" station, pollution was transferred from the industrial complexes of the Baikal region. In the conclusion of the article, it is concluded that there are two main mechanisms of atmospheric pollution in the central ecological zone of Lake Baikal: direct transfer of individual weakly scattered plumes of separate regional thermal power plants with jet air currents at the upper boundary of the night boundary layers of the atmosphere (from 200 to 500 m above ground level); large-scale northwestern transport of mixed emissions from many regional and remote sources under the influence of synoptic-scale processes. Small settlements located on the coast, due to small volumes of emissions, do not make a significant contribution to the pollution of the lake's atmosphere. The work was supported by the Ministry of Science and Higher Education of the Russian Federation (grant No. 075-15-2020-787 for implementation of large scientific project "Fundamentals, methods and technologies for digital monitoring and forecasting of the environmental situation on the Baikal natural territory".

Ice–water heat exchange during ice growth in Lake Baikal

2014 ◽  
Vol 40 (3) ◽  
pp. 599-607 ◽  
Author(s):  
I.A. Aslamov ◽  
V.V. Kozlov ◽  
G.B. Kirillin ◽  
I.B. Mizandrontsev ◽  
K.M. Kucher ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Lake Baikal ◽  
Ice Growth ◽  
Ice Water
Sign in / Sign up

Export Citation Format

Share Document