Ventilation of the Baltic Sea deep water: A brief review of present knowledge from observations and models

• Autorzy: Markus Meier H.E. , Feistel R. , Piechura J. , Arneborg L. , Burchard H. , Fiekas V. , Golenko N. , Kuzmina N. , Mohrholz V. , Nohr C. , Paka V.T. , Sellschopp J. , Stips A. , Zhurbas V.
• Języki publikacji: EN

Abstrakty

EN

The ventilation of the Baltic Sea deep water is driven by either gale-forced barotropic or baroclinic salt water inflows. During the past two decades, the frequency of large barotropic inflows (mainly in winter) has decreased and the frequency of medium-intensity baroclinic inflows (observed in summer) has increased. As a result of entrainment of ambient oxygen-rich water, summer inflows are also important for the deep water ventilation. Recent process studies of salt water plumes suggest that the entrainment rates are generally smaller than those predicted by earlier entrainment models. In addition to the entrance area, the Słupsk Sill and the Słupsk Furrow are important locations for the transformation of water masses. Passing the Słupsk Furrow, both gravity-driven dense bottom flows and sub-surface cyclonic eddies, which are eroded laterally by thermohaline intrusions, ventilate the deep water of the eastern Gotland Basin. A recent study of the energy transfer from barotropic to baroclinic wave motion using a twodimensional shallow water model suggests that about 30% of the energy needed below the halocline for deep water mixing is explained by the breaking of internal waves. In the deep water decade-long stagnation periods with decreasing oxygen and increasing hydrogen sulphide concentrations might be caused by anomalously large freshwater inflows and anomalously high mean zonal wind speeds. In different studies the typical response time scale of average salinity was estimated to be between approximately 20 and 30 years. The review summarizes recent research results and ends with a list of open questions and recommendations.

Słowa kluczowe

EN

Sopot; ventilation; conference; Baltic Sea; deep water; turbulent mixing

• Wydawca: -
• Czasopismo: Oceanologia
• Rocznik: 2006
• Tom: 48
• Numer: S
• Opis fizyczny: p.133-164,fig.,ref.

Twórcy

autor

Markus Meier H.E.

• Swedish Meteorological and Hydrological Institute, Rossby Centre, Folkborgsvagen 1, SE-60176 Norrkoping, Sweden

autor

Feistel R.

autor

Piechura J.

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Arneborg L.

autor

Burchard H.

autor

Fiekas V.

autor

Golenko N.

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Kuzmina N.

autor

Mohrholz V.

autor

Nohr C.

autor

Paka V.T.

autor

Sellschopp J.

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Stips A.

autor

Zhurbas V.