Baroclinic Rossby radius of deformation in the southern Baltic Sea

• Autorzy: Osiński R. , Rak D. , Walczowski W. , Piechura J.
• Języki publikacji: EN

Abstrakty

EN

The first baroclinic Rossby radius of deformation (R1) is a fundamental horizontal scale of mesoscale processes. This scale is important for planning both numerical modelling and study areas. R1 was computed on the basis of an 11-year series of high resolution CTD measurements collected during r/v "Oceania" cruises. The data set covered the three main basins of the Baltic Proper: the Bornholm Basin (BB), the Słupsk Furrow (SF) and the Gdańsk Basin (GB). The smallest mean value of R1 was found in the Gdańsk Basin (5.2 km), the largest one in the Bornholm Deep (7.3 km). The seasonal variability of R1 is lower in the western basin than in the eastern one. The seasonal cycle of R1 may be broken by extreme events, e.g. main Baltic inflows (MBI) of saline water. The inflowing water rebuilds the vertical stratification in the southern Baltic Sea and dramatically changes the R1 values. The difference of R1 between a stagnation period and an inflow situation is shown on the basis of observations made during 2002-2003. The main inflow occurred in winter, after ten years of stagnation, and the very low values of R1 (about 4 km) changed to very high ones (more than 9 km). Analysis of stagnation and saltwater inflow events may throw light on the value of R1 in future climatic scenarios. The potential influence of climate change on Baltic Sea salinity, especially a decrease in MBI activity, may change the baroclinic Rossby radius of deformation and the mesoscale dynamics. Values of R1 are expected to be lower in the future climate than those measured nowadays.

Słowa kluczowe

EN

baroclinic Rossby radius; Brunt-Väisälä frequency; southern Baltic Sea; mesoscale dynamics

• Wydawca: Polish Academy of Sciences, Institute of Oceanology ; Elsevier
• Czasopismo: Oceanologia
• Rocznik: 2010
• Tom: No. 52 (3)
• Strony: 417--429
• Opis fizyczny: bibliogr. 20 poz., tab., wykr.

Twórcy

autor

Osiński R.

autor

Rak D.

autor

Walczowski W.

autor

Piechura J.

• Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, PL-81-712 Sopot, Poland,

Bibliografia

• 1.Alenius P.A., Nekrasov A., Myrberg K., 2003, Variability of the baroclinic Rossby radius in the Gulf of Finland, Cont. Shelf Res., 23 (6), 563-573.
• 2.Chelton D.B., deSzoeke R.A., Schlax M.G., El Naggar K., Siwertz N., 1998, Geographical variability of the first baroclinic Rossby radius of deformation, J. Phys. Oceanogr., 28 (3), 433-460.
• 3.Elken J., Matthäus W., 2008, Baltic Sea oceanography, [in:] Assessment of climate change for the Baltic Sea basin. Annex A.1.1, H. von Storch & A. Omstedt (eds.), BALTEX Publ., Springer, Berlin, 474 pp.
• 4.Emery W. J., Lee W.G., Magaard L., 1984, Geographic and seasonal distributions of Brunt-Väisälä frequency and Rossby radii in the North Pacific and North Atlantic, J. Phys. Oceanogr., 14 (2), 294-317.
• 5.Feistel R., Nausch G., Hagen E., 2006, Unusual inflow activity in 2002-2003 and varying deep-water properties, Oceanologia, 48 (S), 21-35.
• 6.Feistel R., Nausch G., Matthäus W., Hagen E., 2003, Temporal and spatial evolution of the Baltic deep water renewal in spring 2003, Oceanologia, 45 (4), 623-642.
• 7.Fennel W., Seifert T., Kayser B., 1991, Rossby radii and phase speeds in the Baltic Sea, Cont. Shelf Res., 11 (1), 23-36.
• 8.Gill A.E., 1982, Atmosphere-ocean dynamics, Int. Geophys. Ser. 30, Acad. Press, London, 662 pp.
• 9.HELCOM, 2003, The Baltic marine environment 1999-2002, Baltic Sea Environ. Proc. 87, 48 pp.
• 10.Houry S., Dombrowsky E., De Mey P., Minster J.-F., 1987, Brunt-Väisälä frequency and Rossby radii in the South Atlantic, J. Phys. Oceanogr., 17 (10), 1619-1626.
• 11.Matthäus W., Franck H., 1992, Characteristics of major Baltic inflows - a statistical analysis, Cont. Shelf Res., 12 (12), 1375-1400.
• 12.Matthäus W., Lass H.U., 1995, The recent salt inflow into the Baltic Sea, J. Phys. Oceanogr., 25 (2), 280-286.
• 13.Meier H.E.M., 2006, Baltic Sea climate in the late twenty-first century: a dynamical downscaling approach using two global models and two emission scenarios, Clim. Dynam., 27 (1), 39-68, doi: 10.1007/s00382-006-0124-x.
• 14.Meier H.E.M., 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., 2006, Ventilation of the Baltic Sea deep water: A brief review of present knowledge from observations and models, Oceanologia, 48 (S), 133-164.
• 15.Omstedt A., Elken J., Lehmann A., Piechura J., 2004, Knowledge of the Baltic Sea physics gained during the BALTEX and related programmes, Prog. Oceanogr., 63 (1-2), 1-28.
• 16.Piechura J., Beszczyńska-Mőller A., 2004, Inflow waters in the deep regions of the southern Baltic Sea - transport and transformations, Oceanologia, 46 (1), 113-141.
• 17.Piechura J., Walczowski W., Beszczyńska-Mőller A., 1997, On the structure and dynamics of the water in the Słupsk Furrow, Oceanologia, 39 (1), 35-54.
• 18.Reissmann J.H., Burchard H., Feistel R., Hagen H., Lass H.U., Mohrholz V., Nausch G., Umlauf L., Wieczorek G., 2009, Vertical mixing in the Baltic Sea and consequences for eutrophication - a review, Prog. Oceanogr., 82 (1), 47-80, doi:10.1016/j.pocean.2007.10.004.
• 19.Rodhe J., Winsor P., 2002, On the influence of the freshwater supply on the Baltic Sea mean salinity, Tellus, 54 A, 175-186.
• 20.Saenko O.A., 2006, Influence of global warming on baroclinic Rossby radius in the ocean: A model intercomparison, J. Climate, 19 (7), 1354-1360.