Wyniki wyszukiwania - BazTech

1

An Autonomous Hydroacoustic System for studying long-term scattering variability

Szczucka J., Groza K., Poraziński K.

Oceanologia

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2002

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No. 44 (1)

111-122

EN

A new instrument, an Autonomous Hydroacoustic System, was designed to probe a water column acoustically from the bottom to the sea surface. It is capable of operating from a depth of 100 m self sufficiently for up to 10 days. A brief description of its construction and electronic design is provided. Preliminary results from the first field study consisting of a 90-hour series of backscattering measurements are presented.

2

Regional Oceanographic Database as a Modern Sea Research Tool

Piskozub J., Poraziński K., Sagan S., Walczowski W., Wichorowski M., Wyrwiński J

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2000

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Vol. 4, No 1

127-136

EN

Based on the experience acquired from working on the Regional Oceanographic Database at the IOPAS in Sopot a general view of database as a tool for supporting scientific research was presented. Article describes general structure, data flow and techniques of using the ROD.

3

Entrapment of macroplankton in an Arctic fjord basin, Kongsfjorden, Svalbard

Węsławski J.M., Pedersen G., Petersen S. F., Poraziński K.

Oceanologia

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2000

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No. 42 (1)

57-69

EN

This paper presents the results of 15 zooplankton tows collected with a Tucker Trawl (1 m2 opening, net of 2 mm mesh size) in Kongsfjorden (79oN), Svalbard archipelago. The hydroacoustic survey revealed clear differences between the plankton concentrations in the outer and inner fjord basins. Plankton concentrations and fish were observed in the outer fjord, while uniformly scattered objects were detected in the inner basin. The macroplankton community was dominated by Euphausiacea (Thysanoessa inermis, Thysanoessa rashii), Amphipoda (Themisto libellula) and Pteropoda (Limacina helicina). Other taxa were of minor numerical importance. The macroplankton abundance reached 3300 indiv. 100-1 m-3 with a maximum biomass of 100 g wet weight 100-1 m-3 (over 440 kJ 100-1 m-3). L. helicina was advected into the fjord with surface waters, and was found in large abundance (1000 indiv. 100-1 m-3) in the subsurface layers of the inner basin. Euphausids were present in small numbers at the entrance to the fjord, but were found to be very abundant (600 indiv. 100-1 m-3) at the innermost stations, especially in the surface water layer. The estuarine circulation driven by the glacial meltwater discharge is believed to cause the entrapment of zooplankton in the inner fjord basin.

4

Zakłócenia pomiarów hydroakustycznych powodowane przez statek, na przykładzie r/v "Oceania"

Poraziński K.

Hydroacoustics

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2000

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Vol. 3

245--250

PL

Pomiary hydroakustyczne prowadzone są już od czasów I wojny światowej i bez względu na charakter tych pomiarów, najpopularniejszą platformą pomiarową jest jednostka pływająca - statek. Statek prowadzący pomiary na morzu nie jest neutralny w stosunku do badanego środowiska. Wnosi on mnóstwo czynników mogących spowodować zmiany środowiska, jak również mogących mieć wpływ na efekt rejestracji danych pomiarowych.

5

Concentration of marine organisms on the hydrological background - acoustical surveys

Poraziński K.

Hydroacoustics

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1997

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Vol. 1

43--46

EN

This paper presents the result of backscattering layers investigation and correlation with their occurrence and hydrological conditions in the Baltic Sea. Two interesting places are described: the end of Hel Peninsula and the sill of Słupsk Furrew. Figures show the set day - night disturbance by influence of water masses all over the end of Hel Peninsula, and the overflow of water from the North Sea over the sill of Słupsk Furrow. Obtained results are shown as echograms.