Wyniki wyszukiwania

1

Dense bottom waters in Storfjord and Storfjordrenna

100%

Piechura J.

Oceanologia

|

1996

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tom 38

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nr 2

2

The 19th Conference of Baltic Oceanographers

88%

Piechura J.

Oceanologia

|

1994

|

tom 36

|

nr 2

3

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Warming of the West Spitsbergen current and sea ice North of Svalbard

63%

Piechura J., Walczowski W.

Oceanologia

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2009

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tom 51

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nr 2

147-164

According to the results of recent research, besides the atmospheric circulation, it is heat transport to the Arctic Ocean (AO) by ocean currents, the West Spitsbergen Current (WSC) in particular, that is playing a significant role in the process of Arctic warming. Data collected by the Institute of Oceanology, Polish Academy of Sciences (IO PAS), in the Norwegian and Greenland Seas, and Fram Strait during the last 20 years reveal considerable changes in the amount of heat transported by the WSC into the Arctic Ocean. An increase in Atlantic Water (AW) temperature and the intensification of heat transport were observed in 2004–06; after this period, both parameters decreased. The aim of this study was to find out whether the fluctuations in heat input by the WSC have influenced the sea-ice distribution around Svalbard. In fact they do, but oceanic heat transport should nonetheless be regarded as just one of many processes influencing sea-ice behaviour.

4

Interannual variability in the hydrophysical fields of the Norwegian-Barents Seas confluence zone

63%

Piechura J., Walczowski W.

Oceanologia

|

1996

|

tom 38

|

nr 1

5

Inflow waters in the deep regions of the Southern Baltic Sea - transport and transformations

63%

Piechura J., Beszczynska-Moller A.

Oceanologia

|

2004

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tom 46

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nr 1

A medium-sized inflow (about 200 km3 according to IOW data, - personal communication) of saline water into the southern Baltic Sea occurred during January 2003. Unlike any previously observed inflow, this one brought very cold water, of temperatures around 1-2oC and less. Since the temperature of the deep water in the southern Baltic before the inflow was exceptionally high (11-12oC), the inflowing waters produced dramatic changes and a steep temperature gradient. The movement of the inflowing waters through the deep basins and channels of the Baltic Sea from the Arkona Basin to the Gdańsk Deep during next 4-8 months is described. Frequent mesoscale structures and intensive mixing followed the eastward transport of the inflow water, particularly in the Bornholm Deep and Słupsk Furrow. The present paper is based on data collected during 6 cruises r/v "Oceania" between December 2002 and August 2003. The last cruise in August took place in order to assess the long-term consequences of the inflow.

6

The Arctic Front: structure and dynamics

63%

Piechura J., Walczowski W.

Oceanologia

|

1995

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tom 37

|

nr 1

7

Inflow waters in the deep regions of the Southern Baltic Sea - transport and transformations

63%

Piechura J., Beszczynska-Moller A.

Oceanologia

|

2003

|

tom 45

|

nr 4

A medium-sized inflow (about 200 km3 according to IOW data, – personal communication) of saline water into the southern Baltic Sea occurred during January 2003. Unlike any previously observed inflow, this one brought very cold water, of temperatures around 1–2◦C and less. Since the temperature of the deep water in the southern Baltic before the inflow was exceptionally high (11–12◦C), the inflowing waters produced dramatic changes and a steep temperature gradient. The movement of the inflowing waters through the deep basins and channels of the Baltic Sea from the Arkona Basin to the Gdańsk Deep during next 4–8 months is described. Frequent mesoscale structures and intensive mixing followed the eastward transport of the inflow water, particularly in the Bornholm Deep and Słupsk Furrow. The present paper is based on data collected during of 6 cruises r/v ‘Oceania’ between December 2002 and August 2003. The last cruise in August took place in order to assess the long-term consequences of the inflow.

8

Baroclinic Rossby radius of deformation in the Southern Baltic Sea

51%

Osinski R., Rak D., Walczowski W., Piechura J.

Oceanologia

|

2010

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tom 52

|

nr 3

417-429

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.

9

Heat and salt fluxes in the West Spitsbergen Current area in summer

51%

Piechura J., Osinski R., Petelski T., Wozniak S. B.

Oceanologia

|

2002

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tom 44

|

nr 3

Fluxes of radiation, sensible and latent heat, and fluxes of heat and salt within the upper layer of the ocean were calculated on the basis of measurements carried out in the area of the Norwegian-Atlantic and West Spitsbergen Currents during summer 2000. The sea surface radiation balance was calculated from direct measurements of downward and upward short-wave (solar) radiation, the net radiation fluxes and sea surface temperature. The daily doses of radiation energy reaching and leaving the sea surface were also estimated. To calculate the vertical heat fluxes in the atmospheric boundary layer the bulk parameterisation method was used. In most cases, the calculated heat fluxes were rather low, the average sensible heat flux was c. 10 Wm−2, and the latent heat flux about one order of magnitude higher; this is what could be expected in summer. Salt fluxes to the air in the process of aerosol production are very small and can be neglected. In summer the highest quantities of heat and salt are exchanged during mixing with surrounding waters. According to our measurements, Atlantic Water on its northward course from about 70◦N to 79◦ N loses about 100 TWof heat and 900 × 103 kg of salt. We thought it could be interesting to find out what happens to them. Some preliminary results of our investigation are presented here.

10

Some results of research on internal waves in the Stolpe Sill area

51%

Golenko N. N., Beszczynska-Moller A., Piechura J., Walczowski W.

Oceanologia

|

1999

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tom 41

|

nr 4

11

On the structure and dynamics of the water in the Slupsk Furrow

51%

Piechura J., Walczowski W., Beszczynska-Moller A.

Oceanologia

|

1997

|

tom 39

|

nr 1

12

What we know about the Baltic Sea: a summary of BSSC 2005

51%

Piechura J., Pempkowiak J., Radziejewska T., Uscinowicz S.

Oceanologia

|

2006

|

tom 48

|

nr S

13

The major Baltic inflow in January 2003 and preconditioning by smaller inflows in summer-autumn 2002: a model study

51%

Meier H. E. M., Doscher R., Broman B., Piechura J.

Oceanologia

|

2004

|

tom 46

|

nr 4

Using the results of the Rossby Centre Ocean model (RCO) the Baltic inflows in summer/autumn 2002 and January 2003 have been studied. The model results were extracted from a long simulation with observed atmospheric forcing starting in May 1980. In RCO a bottom boundary layer model was embedded. Both the smaller inflows and the major inflow in January 2003 are simulated in good agreement with observations. We found that a total of 222 km3 water entered the Baltic in January; the salinity of 94 km3 was greater than 17 PSU. In August/September 2002 the outflow through the Sound and inflow across the Darss Sill were simulated. The net inflow volume amounted to about 50 km3.

14

Respiratory function, physical activity and body composition in adult rural population

45%

Rozek-Piechura K., Ignasiak Z., Slawinska T., Piechura J., Ignasiak T.

Annals of Agricultural and Environmental Medicine

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2014

|

tom 21

|

nr 2

15

Evidence for a warm water inflow into the Baltic Proper in summer 2003

45%

Feistel R., Nausch G., Heene T., Piechura J., Hagen E.

Oceanologia

|

2004

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tom 46

|

nr 4

The exceptional warm water inflow into the Baltic Sea in summer 2002, which preceded the major Baltic inflow of January 2003, was surprisingly repeated in modified form in summer 2003. Its warm waters even replaced the renewed, cold inflow waters in the eastern Gotland Basin and commenced another warm period in its deep layers, where the previous one had lasted from 1997 to 2003. Details of the temporal and spatial behaviour of this new baroclinic inflow are presented from various measurements carried out from the Kiel Bight up to Gotland, covering the Darss Sill, the Arkona, Bornholm, Gdańsk Basins and the Słupsk Channel, focused mainly on the time period between July 2003 and July 2004. Hypothetically, the repetition of these exceptional warm inflow events could be regarded as a possible regional indicator for global climatic change.

16

On the possibility of convective overturning in the Slupsk Furrow overflow of the Baltic Sea

33%

Zhurbas V., Elken J., Paka V., Piechura J., Chubarenko I., Vali G., Golenko N., Shchuka S.

Oceanologia

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2011

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tom 53

|

nr 3

Closely spaced CTD transects across the Słupsk Furrow displayed a ‘downward- bending’ of salinity contours below the salinity interface on the southern flank due to a transverse circulation in the saline water overflow. Numerical simulation of a gravity current in an idealized channel with geometry, dimensions and initial density stratification all much the same as in the Słupsk Furrow was applied to verify whether the downward-bending could be transformed into an inverted density stratification. Some arguments in favour of the possibility of convective overturning due to the differential transverse advection beneath the gravity current, brought on by the numerical simulations, are discussed.

17

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

27%

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.

Oceanologia

|

2006

|

tom 48

|

nr S

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.

18

Pojutrze juz bylo

26%

Weslawski J. M., Piechura J.

Wiedza i Życie

|

2004

|

nr 07

30-34

Ograniczanie wyników

Dense bottom waters in Storfjord and Storfjordrenna

The 19th Conference of Baltic Oceanographers

Warming of the West Spitsbergen current and sea ice North of Svalbard

Interannual variability in the hydrophysical fields of the Norwegian-Barents Seas confluence zone

Inflow waters in the deep regions of the Southern Baltic Sea - transport and transformations

The Arctic Front: structure and dynamics

Inflow waters in the deep regions of the Southern Baltic Sea - transport and transformations

Baroclinic Rossby radius of deformation in the Southern Baltic Sea

Heat and salt fluxes in the West Spitsbergen Current area in summer

Some results of research on internal waves in the Stolpe Sill area

On the structure and dynamics of the water in the Slupsk Furrow

What we know about the Baltic Sea: a summary of BSSC 2005

The major Baltic inflow in January 2003 and preconditioning by smaller inflows in summer-autumn 2002: a model study

Respiratory function, physical activity and body composition in adult rural population

Evidence for a warm water inflow into the Baltic Proper in summer 2003

On the possibility of convective overturning in the Slupsk Furrow overflow of the Baltic Sea

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

Pojutrze juz bylo