Structure and evolution of the cold intermediate layer in the southeastern part of the Baltic Sea by the field measurement data of 2004–2008

Oceanology ◽  
2015 ◽  
Vol 55 (1) ◽  
pp. 25-35 ◽  
Author(s):  
N. B. Stepanova ◽  
I. P. Chubarenko ◽  
S. A. Shchuka
Keyword(s):  
Baltic Sea ◽  
Field Measurement ◽  
Intermediate Layer ◽  
Measurement Data ◽  
Cold Intermediate Layer ◽  
The Baltic Sea ◽  
Southeastern Part ◽  
The Baltic

scholarly journals On contribution of horizontal and intra-layer convection to the formation of the Baltic Sea cold intermediate layer

2008 ◽  
Vol 5 (4) ◽  
pp. 581-623
Author(s):  
I. P. Chubarenko ◽  
N. Y. Demchenko
Keyword(s):  
Baltic Sea ◽  
Intermediate Layer ◽  
Heat Content ◽  
Field Measurements ◽  
Open Water ◽  
Early Spring ◽  
Cold Intermediate Layer ◽  
The Baltic Sea ◽  
The Baltic ◽  
Fast Increase

Abstract. Seasonal cascades down the coastal slopes and intra-layer convection are considered as the two mechanisms contributing to the Baltic Sea cold intermediate layer (CIL) formation. On the base of TS-diagrams, mean-annual and real-time temperature profiles, the CIL features are re-analyzed. The presence within the CIL of water with temperature below that of maximum density (Tmd) and that at the local surface allows tracing its formation. Field measurements are presented, showing specific features of denser water formation in marine environment. It is argued that such cascades formed during early spring heating (March–April) – before reaching the Tmd – are the source of the coldest waters of the CIL. Fast increase of the open water heat content during further spring heating indicates that horizontal exchange rather than direct solar heating is responsible for that. When the surface is covered with water, heated above the Tmd, the conditions within the CIL become favorable for intralayer convection due to the presence of waters of Tmd in intermediate layer, which can explain the observed increase of its salinity and deepening with time.

scholarly journals On contribution of horizontal and intra-layer convection to the formation of the Baltic Sea cold intermediate layer

Ocean Science ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 285-299 ◽  
Author(s):  
I. Chubarenko ◽  
N. Demchenko
Keyword(s):  
Baltic Sea ◽  
Intermediate Layer ◽  
Vertical Mixing ◽  
Heat Content ◽  
Field Measurements ◽  
Open Water ◽  
Early Spring ◽  
Cold Intermediate Layer ◽  
The Baltic Sea ◽  
The Baltic

Abstract. Seasonal cascades down the coastal slopes and intra-layer convection are considered as the two additional mechanisms contributing to the Baltic Sea cold intermediate layer (CIL) formation along with conventional seasonal vertical mixing. Field measurements are presented, reporting for the first time the possibility of denser water formation and cascading from the Baltic Sea underwater slopes, which take place under fall and winter cooling conditions and deliver waters into intermediate layer of salinity stratified deep-sea area. The presence in spring within the CIL of water with temperature below that of maximum density (Tmd) and that at the local surface in winter time allows tracing its formation: it is argued that the source of the coldest waters of the Baltic CIL is early spring (March–April) cascading, arising due to heating of water before reaching the Tmd. Fast increase of the open water heat content during further spring heating indicates that horizontal exchange rather than direct solar heating is responsible for that. When the surface is covered with water, heated above the Tmd, the conditions within the CIL become favorable for intralayer convection due to the presence of waters of Tmd in intermediate layer, which can explain its well-known features – the observed increase of its salinity and deepening with time.

Acclimation limits of Fucus evanescens along the salinity gradient of the southwestern Baltic Sea

2019 ◽  
Vol 62 (1) ◽  
pp. 31-42
Author(s):  
Katharina Romoth ◽  
Petra Nowak ◽  
Daniela Kempke ◽  
Anna Dietrich ◽  
Christian Porsche ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Salinity Gradient ◽  
Phylogenetic Analyses ◽  
Measurement Data ◽  
Limiting Factor ◽  
Photosynthetic Parameters ◽  
Similar Species ◽  
The Baltic Sea ◽  
Fucus Evanescens ◽  
The Baltic

Abstract Over recent decades, the neophyte Fucus evanescens has extended eastwards along the salinity gradient within the Baltic Sea, indicating gradual adaptation to low salinity conditions. To find out whether F. evanescens can migrate further into the Baltic Sea and potentially become a competitor to the native F. vesiculosus, the acclimation potentials of different F. evanescens and F. vesiculosus populations were investigated with respect to habitat salinity. For both species, pigmentation, water content, and photosynthetic rate were measured under laboratory and field conditions. The instantaneous measurement data and incubation experiment did not show clear differences in the measured photosynthetic parameters between different salinity levels (6–20), or between species. Maximum likelihood phylogenetic analyses of the nuclear marker PDI (a putative protein disulfide isomerase) separated F. vesiculosus and F. evanescens into well-defined groups supporting the hypothesis that the two very similar species do not represent different morphotypes of the same species/gene pool. These findings indicate that – at least for the vegetative stage of F. evanescens – salinity may not be a limiting factor for a further spread into the Baltic Sea.

scholarly journals Effect of Maneuvering on Ice-Induced Loading on Ship Hull: Dedicated Full-Scale Tests in the Baltic Sea

2020 ◽  
Vol 8 (10) ◽  
pp. 759
Author(s):  
Mikko Suominen ◽  
Fang Li ◽  
Liangliang Lu ◽  
Pentti Kujala ◽  
Anriëtte Bekker ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Measurement Data ◽  
Full Scale ◽  
The Baltic Sea ◽  
Load Duration ◽  
Ship Control ◽  
Level Ice ◽  
The Baltic ◽  
Full Scale Tests ◽  
The Impact

Maneuvers in level ice are common operations for icebreakers and polar supply vessels. Maneuvering exposes the midship and stern area to ice interaction, influencing the magnitude and frequency of ice-induced loading in these areas. However, full-scale measurements do not typically cover the midship and stern areas, as measurements have commonly focused on the bow area. Controlled maneuvering tests were conducted during the ice trials of S.A. Agulhas II in the Baltic Sea. During these tests, ice-induced loading at different hull areas was measured simultaneously with ship control, navigation, and ice condition data. This work studied the effect of maneuvers on the characteristics and statistics of ice-induced loading at different hull areas and compared the impact to ahead operations. The study showed that the maneuvers had minor impact to the magnitude, frequency, and duration of loading at the bow and bow shoulder. On the other hand, maneuvers had a clear effect on the load magnitude and frequency at the stern shoulder. Additionally, a statistical analysis showed that the load magnitude increased as a function of load duration in all hull areas. Furthermore, the analyzed measurement data are presented and made available with the paper.

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