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Wyszukujesz frazę "deep water condition" wg kryterium: Wszystkie pola


Wyświetlanie 1-7 z 7
Tytuł:
Synoptic changes in the deep rim current during stagnant hydrographic conditions in the Eastern Gotland Basin, Baltic Sea
Autorzy:
Hagen, E.
Feistel, R.
Powiązania:
https://bibliotekanauki.pl/articles/49138.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Gotland Basin
hydrography
deep water condition
current measurement
Baltic Sea
Baltic Monitoring Programme
Opis:
Hydrographic and current measurements are analysed for stagnant deep-water conditions over the south-eastern topographic flank of the Eastern Gotland Basin (EGB) in April 2000. Results suggest a prevailing barotropic motion mode on a synoptic scale of several days. Deep along-slope volume transports derived from subsurface current meter moorings are compared with those of the baroclinic fraction of geostrophic motions crossing the plane of a hydrographic section. This was aligned perpendicular to deep isobaths and was repeated 40 times with a time step of six hours. Changes in regional winds produced a quasi-ten day cycle in the filling level of the Baltic Proper. Associated wave-like fluctuations of the mass field propagated cyclonically with a velocity of about 0.04 m s−1 around the deep basin’s rim. It is concluded that associated changes in deep volume transports result mainly from barotropically governed advection processes and that those of the baroclinic component of geostrophic currents provide a qualitatively and quantitatively quite inaccurate description of related transport fluctuations on a daily scale.
Źródło:
Oceanologia; 2007, 49, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temporal and spatial evolution of the Baltic deep water renewal in spring 2003
Autorzy:
Feistel, R.
Nausch, G.
Matthaus, W.
Hagen, E.
Powiązania:
https://bibliotekanauki.pl/articles/48009.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
temporal evolution
inflow
spring
deep water renewal
Baltic Sea
oxygen condition
spatial evolution
Opis:
In January 2003, a deep-water renewal process in the Baltic Sea commenced with an inflow of about 200 km3 of cold and well oxygenated water from the Kattegat, half of which was of salinity >17 PSU; it is considered to be the most important inflow since 1993. Related front propagation and the ventilation of anoxic waters between the western and the central Baltic were recorded by the Darss Sill measuring mast, the Arkona Basin buoy, a subsurface mooring in the Eastern Gotland Basin, and hydrographic research cruises conducted in January, February, March, May and August 2003. Already in May, the central Gotland Basin was reached by water with near-bottom oxygen concentrations among the highest ever recorded there. A comprehensive review of the observed spatial and temporal structures together with additional background data is presented. Estimates of the intensity of the present inflow are discussed.
Źródło:
Oceanologia; 2003, 45, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrographic and hydrochemical conditions in the Gotland Deep area between 1992 and 2003
Autorzy:
Nausch, G.
Matthaus, W.
Feistel, R.
Powiązania:
https://bibliotekanauki.pl/articles/48546.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
nutrient pool
temperature
hydrography
hydrochemical condition
ventilation
nutrient distribution
bottom water
salinity
Baltic Sea
stagnation period
hydrographic condition
Gotland Deep
Opis:
The paper describes the hydrographic-hydrochemical development in the eastern Gotland Basin between the major saltwater inflows into the Baltic Sea in 1993 and 2003. This period is characterised by only low inflow activity. The most important hydrographic events were the effects of the very strong inflow in 1993 and the weak inflows in 1993/1994 and 1997. The 1993/1994 inflows led to deep-water renewal, a steep fall in deep-water temperatures, and increasing salinity. The effects of the inflow of very warm, saline and oxygen-rich water in autumn 1997 were observed in the deep water in 1998, resulting in temperatures rising to 7◦C. The recent renewal in spring 2003 is reflected in the decreasing temperature, higher salinity and improved ventilation of the bottom water. Changes in the redox conditions exert a considerable influence on the nutrient distribution. During stagnation periods, there is enrichment of phosphate and ammonium, while nitrate is absent. Thus, around 31 μmol l−1 ammonium and 7 μmol l−1 phosphate were measured prior to the water renewal in 2003. Deepwater ventilation results in lower phosphate concentrations of around 2 μmol l−1, the nitrification of ammonium and the occurrence of nitrate. For the observation period, an estimate of nutrients stored in the deep water was done for the eastern Gotland Basin. During the recent stagnation period, there was an increase of up to 150% in the phosphate pool below the halocline, whereas the pool of inorganic nitrogen compounds decreased to 80% compared with 1992 when the previous stagnation period had ended. Under specific circumstances, these unbalanced nutrients can be made available to the upper water layers and can induce large-scale blooms of algae, especially of cyanobacteria.
Źródło:
Oceanologia; 2003, 45, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania stanu technicznego studni głębinowych wodociągu "Dąbrowa" w Łodzi
Assessing the condition of deep wells for Dabrowa Waterworks: A case study
Autorzy:
Jodłowski, A.
Piąstka, W.
Powiązania:
https://bibliotekanauki.pl/articles/237828.pdf
Data publikacji:
2008
Wydawca:
Polskie Zrzeszenie Inżynierów i Techników Sanitarnych
Tematy:
ujęcie wody
woda podziemna
studnia głębinowa
water intake
groundwater
deep well
Opis:
Przedstawiono analizę wyników badań związanych z oceną stanu technicznego ośmiu wybranych dolnokredowych studni głębinowych wodociągu "Dąbrowa" w Łodzi. Przeprowadzone badania dotyczą najstarszych studni, których eksploatacja wiąże się z wieloma problemami obejmującymi m.in. kolmatację, piaszczenie, zmniejszenie wydajności eksploatacyjnej i zmianę jakości wody. Analizie poddano także obserwacje dotyczące liczby, przyczyn i czasu postoju studni. Obiektami charakteryzującymi się najgorszym stanem technicznym wśród analizowanych studni okazały się najstarsze studnie dolnokredowe. Świadczą o tym zarówno wyniki przeprowadzonych badań zmian parametrów ich pracy, jak i jakości ujmowanej wody. Potwierdziły to również wyniki badań stanu rur konstrukcyjnych i filtru uzyskane w drodze inspekcji telewizyjnej otworów studziennych. Wykazano, że przyczynami przerw w pracy studni były głównie dyspozycje ograniczenia produkcji wody wodociągu "Dąbrowa". Postoje wynikające z awarii eksploatowanych instalacji i urządzeń oraz rurociągów przesyłowych, jak również spowodowane przerwami w zasilaniu energetycznym nie stanowiły istotnego problemu, chociaż wymagają bardziej szczegółowych badań w oparciu o teorię niezawodności.
The objects under study are eight Lower Cretaceous deep wells operated by the Dabrowa Waterworks, which is part of the water supply system for the city of Lodz. The deep wells chosen were subjected to assessment of their technical condition, since their operation raised serious technological problems (e.g. due to silting-up, decline in yield, deterioration of water quality). Observations about the causes and frequency of failure, as well as the length of time when the wells were not in service, were also scrutinized. Of the objects chosen, the oldest Lower Cretaceous deep wells were found to be in the worst condition. This finding was not only substantiated by the analysis of changes in their operating parameters or in the quality of the water being taken in, but was also confirmed by the video inspection of the well's interior, which enabled the condition of the pipes and that of the filters to be examined. It was demonstrated that discontinuities in the operation of the wells occured predominantly when the order was given to reduce water production in the Dabrowa Waterworks. Discontinuities caused by the failure of particular installations or distribution pipes, as well as the discontinuities resulting from power stoppage, are of minor importance but still require close examinations based on the reliability theory.
Źródło:
Ochrona Środowiska; 2008, 30, 3; 45-51
1230-6169
Pojawia się w:
Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Processes and factors influencing the through-flow of new deepwater in the Bornholm Basin
Autorzy:
Stigebrandt, A.
Powiązania:
https://bibliotekanauki.pl/articles/49102.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
hydrographic condition
Bornholm Basin
salinity
oxygen concentration
vertical stratification
deep water
Baltic Sea
Opis:
This paper is based on the idea that the hydrographical conditions in the Bornholm Basin, and any other basin, can be understood from knowledge of general hydromechanical principles and basin-specific factors. Published results on the variability of the vertical stratification are shown and discussed. Such analyses demonstrate the residence time of water at different depth levels. Different modes of currents forced by winds and by stratification gradients at open vertical boundaries are presented. Vertical mixing is discussed and published results for the Bornholm Basin are shown. An experiment demonstrates that the diffusive properties of the enclosed basin, i.e. below the sill depth of the Słupsk Furrow, can be computed quite well from the horizontal mean vertical diffusivity obtained from historical hydrographical observations. A published two decades long simulation of the vertical stratification shows that the through flow and modification of new deepwater in the Bornholm Basin can be well described based on existing knowledge regarding crucial hydromechanical processes. It also suggests, indirectly, that there should be a weak anticyclonic circulation above the sill depth, which is supported by current measurements.
Źródło:
Oceanologia; 2017, 59, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Warm waters of summer 2002 in the deep Baltic Proper
Autorzy:
Feistel, R.
Nausch, G.
Mohrholz, V.
Lysiak-Pastuszak, E.
Seifert, T.
Matthaus, W.
Kruger, S.
Hansen, I.S.
Powiązania:
https://bibliotekanauki.pl/articles/47540.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
temperature
hydrography
inflow
warm water
summer
salinity
Baltic Sea
oxygen condition
Opis:
From October 2002 until March 2003 surprisingly warm, oxygenated waters were frequently encountered in the Baltic Sea in the area between the Bornholm and Fårö Deeps from the halocline down to the bottom. Owing to their ventilation effect in the stagnating deep waters, their occasional observations have partly been incorrectly attributed to the inflow events of October 2002 or January 2003. The emergence of some of these waters can be traced back to the exceptional summer weather conditions in August and September 2002 in central Europe. The warm waters played a remarkable renewal pacemaker role for the subsequent important winter inflow of January 2003. The evolution of this summer inflow is described and possible causes are discussed.
Źródło:
Oceanologia; 2003, 45, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PO4 release at the sediment surface under anoxic conditions: a contribution to the eutrophication of the Baltic Sea?
Autorzy:
Schneider, B.
Powiązania:
https://bibliotekanauki.pl/articles/49162.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
anoxia
biogeochemical condition
carbon dioxide
deep water
dissolved inorganic nitrogen
eutrophication
hydrogen sulphide
mineralization
nutrient concentration
oxygen
phosphate
sediment
Opis:
The vertical profiles of phosphate, total CO2 and oxygen/hydrogen sulphide were determined in the deep water of the Gotland Sea during March 2003 to July 2006 with a temporal resolution of 2–3 months. This time span included the shift from anoxic to oxic conditions resulting from a water renewal event, as well as the transition back to anoxic waters during the subsequent two-year stagnation period. The data from depths below 150 m were used to identify and quantify phosphate release and removal processes. The relationship between the total CO2 generated by mineralization (CT1 min) and the PO4 concentrations indicated that the initial decrease in the phosphate concentrations after the inflow of oxygen-rich water was mainly a dilution effect. Only about one third of the PO4 removal was a consequence of the precipitation of insoluble iron-3-hydroxo-phosphates (Fe-P), which occurred slowly at the sediment surface under oxic conditions. From the CT1 min/PO4 ratios it was also concluded that the formation of Fe-P was reversed during the later phase of the stagnation, when the redoxcline approached a depth of 150 m. A phosphate mass balance was performed for four deep water sub-layers in order to quantify the dissolution of Fe-P during the stagnation period and thus to estimate the amount of Fe-P deposited during the last inflow of oxygen-rich water. A value of about 50 mmol-P m−2 was found, which refers to the specific biogeochemical conditions during the change from anoxic to oxic conditions that preceded the stagnation period.
Źródło:
Oceanologia; 2011, 53, (1-TI)
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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