scholarly journals Water exchange between the inner and outer archipelago areas of the Finnish Archipelago Sea in the Baltic Sea

2020 ◽  
Vol 70 (11) ◽  
pp. 1421-1437
Author(s):  
Elina Miettunen ◽  
Laura Tuomi ◽  
Kai Myrberg
Keyword(s):  
Baltic Sea ◽  
Wind Direction ◽  
Particle Model ◽  
Water Age ◽  
Lagrangian Particle ◽  
Southern Boundary ◽  
Seasonal Thermocline ◽  
Archipelago Sea ◽  
Prevailing Wind Direction ◽  
The Baltic

Abstract We studied the water age and transport of passive tracers in the Archipelago Sea, Baltic Sea, using the COHERENS 3D hydrodynamic model and the OpenDrift Lagrangian particle model. The mean water age, which was calculated with COHERENS over a period of 6 years, varied between 1 and 3 months in the outer archipelago and between 3 and 6 months in the middle archipelago. The water age was highest in the inner archipelago, up to 7 months. As the density stratification is weak in large parts of this area, except for the seasonal thermocline, significant differences in the water age between the surface and bottom layers were seen only in the river mouths and in the deep channels of the middle archipelago. The Lagrangian particle simulations showed that the middle archipelago is more open towards the north than south. From the northern boundary, the Bothnian Sea, the largest transport to the middle archipelago occurred with NW winds. Due to the geometry and density of the islands in the area, the prevailing wind direction, SW, alone is not optimal for transporting tracer particles to the middle archipelago. From the southern boundary, the Baltic Proper, transport to the middle archipelago occurred mainly with SE winds and during events when the wind direction shifted from SW to SE or vice versa. The transport further into the inner archipelago was limited to only a few cases, indicating that the inner archipelago is fairly sheltered from transport from the outer archipelago.

Water exchange in a coastal archipelago in the northern Baltic Sea

2020 ◽  
Author(s):  
Elina Miettunen ◽  
Laura Tuomi ◽  
Kai Myrberg
Keyword(s):  
Baltic Sea ◽  
Hydrodynamic Model ◽  
Water Exchange ◽  
Particle Model ◽  
Water Age ◽  
Archipelago Sea ◽  
Tracer Particles ◽  
Open Sea ◽  
Prevailing Wind Direction ◽  
Model Setup

<p>The Archipelago Sea, situated in the northern Baltic Sea, consists of over 40 000 small islands and islets. It is a vulnerable area and suffers from continuous nutrient loading from the catchment and also from the background loading from the surrounding open sea areas. We studied water exchange in this complex coastal archipelago by simulating the water age and currents with a 3D hydrodynamic model COHERENS. The Archipelago Sea model setup has a horizontal resolution of c. 460 m and its boundary conditions are from a model setup that covers the whole Baltic Sea with a resolution of 3.7 km. The current fields produced with the hydrodynamic model were used to simulate the transport patterns of passive tracers through the archipelago with a Lagrangian particle model OpenDrift.</p><p>The mean water age was up to three months in the outer archipelago and up to seven months in the narrowest waterways in the inner archipelago. The effect of rivers on the water age was seen mostly only in the inner archipelago. The transport of passive tracer particles from the open sea areas, across the Archipelago Sea, mostly took place through the outer archipelago. The transport of particles from the outer archipelago towards the inner parts of the archipelago was very sensitive to the geometry and number of islands i.e. density of islands in the area. The prevailing wind direction in the area is from SW, this not being optimal for transport from the outer archipelago to the middle archipelago. For example, with the tracer particles from the southern open sea boundary, most transport to the middle archipelago was seen with SE winds. Transport further to the inner archipelago was limited only to few cases. The results show that the inner archipelago areas are relatively sheltered from transport from the open sea areas and the environmental problems there are in a high extent from local origin.</p>

scholarly journals Quantifying the Wind Direction Climate over the Baltic States using Principal Component Analysis

2021 ◽  
Author(s):  
Tija Sile ◽  
Maksims Pogumirskis ◽  
Juris Seņņikovs ◽  
Uldis Bethers
Keyword(s):  
Principal Component Analysis ◽  
Wind Direction ◽  
Surface Wind ◽  
Principal Component ◽  
Component Analysis ◽  
Baltic States ◽  
Spatial Coverage ◽  
Prevailing Wind Direction ◽  
Pca Method ◽  
The Baltic

<p>Wind direction is an important meteorological parameter, however, its analysis is made difficult by it being a circular variable that cannot easily be averaged. The goal of this study was to identify the main features of wind direction climate over the Baltic States in a methodical way. We used Principal Component Analysis (PCA) for this purpose.</p><p>Two data sets were used: UERRA re-analysis with 11 km horizontal resolution and surface wind direction observations from Latvian stations. We used PCA on both of these datasets and analyzed the results together. Such an approach enabled comparison of the wind direction climate of the reanalysis with the observations. However, preliminary results suggested applying PCA also on the subset of UERRA data that corresponds to observation stations. This eliminates effects caused by differences in spatial coverage between  gridded and station datasets.</p><p>To verify the quality of the reanalysis independently of the PCA method, Earth Mover’s Distance (EMD) was used to directly compare wind direction distributions at the station grid points with observations.</p><p>Results show good correspondence overall between the reanalysis data and the observations. The PCA method identifies SW as the prevailing wind direction, in good agreement with the expectations. The PCA results enable identification of the main wind direction features of the region, such as increased frequency of northern winds during the summer and increased frequency of southern winds during the winter that can be explained by synoptic scale processes. Additionally, the PCA method identifies coast parallel flows created by mesoscale interaction between the Baltic Sea and the dry land, and wind deflection around terrain (hills up to 300 m above sea level).</p><p>This approach could be generalized to other regions and help create a more systematic understanding about wind direction climate, as well as assist in quantifying the performance of reanalysis and identify meteorological processes that need to be investigated further.</p><p>Corresponding author is grateful to the project “Mathematical modelling of weather processes - development of methodology and applications for Latvia (1.1.1.2/VIAA/2/18/261)” for financial support.</p>

scholarly journals Comment to Hansson, S. et al. (2017): “Competition for the fish – fish extraction from the Baltic Sea by humans, aquatic mammals, and birds”, with special reference to cormorants, perch, and pikeperch

2018 ◽  
Vol 75 (5) ◽  
pp. 1832-1836 ◽  
Author(s):  
Outi Heikinheimo ◽  
Hannu Lehtonen ◽  
Aleksi Lehikoinen
Keyword(s):  
Baltic Sea ◽  
Scientific Knowledge ◽  
Coastal Waters ◽  
Fish Assemblages ◽  
The Baltic Sea ◽  
Piscivorous Fish ◽  
Archipelago Sea ◽  
Fish Predators ◽  
The Baltic ◽  
Aquatic Mammals

Abstract Hansson et al. (2017) concluded that competition between fisheries and piscivorous mammals and birds exists in the Baltic Sea, based on the estimation of biomass of the fish species consumed in the ICES subdivisions. We compared their results to the data and scientific knowledge from the coastal waters of Finland and show that local differences in fisheries, fish assemblages and abundance of predators should be taken into account to reliably assess potential competition. Hansson et al. (2017) did not include the piscivorous fish in their analysis, but these may be the most important predators. In the Archipelago Sea, for instance, the consumption by fish predators is considerably larger than that of cormorants.

scholarly journals Regional circulation patterns inducing coastal upwelling in the Baltic Sea

2021 ◽  
Vol 144 (3-4) ◽  
pp. 905-916
Author(s):  
Ewa Bednorz ◽  
Marek Półrolniczak ◽  
Arkadiusz M. Tomczyk
Keyword(s):  
Baltic Sea ◽  
Sea Level ◽  
Coastal Upwelling ◽  
Principal Component ◽  
Synoptic Situation ◽  
The Baltic Sea ◽  
Synoptic Patterns ◽  
Regional Circulation ◽  
Prevailing Wind Direction ◽  
The Baltic

AbstractAtmospheric feedback involved in the occurrence of coastal upwelling in a small semi-enclosed sea basin, i.e., the Baltic Sea, was analysed, and the regional circulation conditions triggering upwelling in different coastal sections were identified. Upwelling in the summer season (June–August, years 1982–2017) was recognized on the basis of sea surface temperature patterns. Circulation conditions were defined using (1) the established daily indices of zonal and meridional airflow and (2) the synoptic situation at sea level distinguished by applying rotated principal component analysis to sea level pressure data. The 12 daily synoptic patterns differed substantially in the intensity and location of their pressure centres. The mean seasonal frequency of upwelling was generally higher along the western Baltic shores than along the meridionally oriented eastern shores and varied from less than 10 to over 30% along the more predestined coastal sections, i.e., the northwestern coast of the Gulf of Bothnia, the northern Gulf of Finland and the southern Swedish coast. Due to the variable orientations of coastlines, upwelling could occur under almost any prevailing wind direction, and thus, each of the classified synoptic patterns could induce upwelling in some coastal sections. As deduced from the pressure fields for each circulation pattern, mostly alongshore winds triggered upwelling, which is in line with the Ekman rule. With time, upwelling could also be induced by the stress of normal to the coastline seaward winds.

Temporal and spatial sedimentation rate variabilities in the eastern Gotland Basin, the Baltic Sea

Boreas ◽  
2002 ◽  
Vol 31 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Christian Christiansen ◽  
Helmar Kunzendorf ◽  
Kay-Christian Emeis ◽  
Rudolf Endler ◽  
Ulrich Struck ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Sedimentation Rate ◽  
The Baltic Sea ◽  
Gotland Basin ◽  
Temporal And Spatial ◽  
The Baltic

Russian Oil: Production and Exports

2003 ◽  
pp. 136-146
Author(s):  
K. Liuhto
Keyword(s):  
Baltic Sea ◽  
Statistical Data ◽  
Oil Production ◽  
The Baltic Sea ◽  
North West ◽  
The North ◽  
Oil Transportation ◽  
Sea Ports ◽  
The Baltic

Statistical data on reserves, production and exports of Russian oil are provided in the article. The author pays special attention to the expansion of opportunities of sea oil transportation by construction of new oil terminals in the North-West of the country and first of all the largest terminal in Murmansk. In his opinion, one of the main problems in this sphere is prevention of ecological accidents in the process of oil transportation through the Baltic sea ports.

Paleoecological study of bottom sediments of the lake Goluboye (Karelian Isthmus) according to the results of diatom analysis

2019 ◽  
pp. 265-269
Author(s):  
Angelina E. Shatalova ◽  
Uriy A. Kublitsky ◽  
Dmitry A. Subetto ◽  
Anna V. Ludikova ◽  
Alar Rosentau ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Bottom Sediments ◽  
Modern Science ◽  
Karelian Isthmus ◽  
The Baltic Sea ◽  
Diatom Analysis ◽  
North West ◽  
The North ◽  
Important Direction ◽  
The Baltic

The study of paleogeography of lakes is an actual and important direction in modern science. As part of the study of lakes in the North-West of the Karelian Isthmus, this analysis will establish the dynamics of salinity of objects, which will allow to reconstruct changes in the level of the Baltic Sea in the Holocene.

Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part III)

2008 ◽  
Vol 37 (4) ◽  
Author(s):  
Małgorzata Leśniewska ◽  
Małgorzata Witak
Keyword(s):  
Baltic Sea ◽  
The South ◽  
Gulf Of Gdańsk ◽  
The Baltic Sea ◽  
Southern Baltic Sea ◽  
Gulf Of Gdansk ◽  
Southern Baltic ◽  
The Baltic ◽  
Palaeoenvironmental Changes

Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part III)The palaeoenvironmental changes of the south-western part of the Gulf of Gdańsk during the last 8,000 years, with reference to the stages of the Baltic Sea, were reconstructed. Diatom analyses of two cores taken from the shallower and deeper parts of the basin enabled the conclusion to be drawn that the microflora studied developed in the three Baltic phases: Mastogloia, Littorina and Post-Littorina. Moreover, the so-called anthropogenic assemblage was observed in subbottom sediments of the study area.

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