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Wyszukujesz frazę "sea current" wg kryterium: Temat


Tytuł:
Aggregating sea surface hydrodynamic forecasts from multi-models for European seas
Autorzy:
Frishfelds, V.
She, J.
Murawski, J.
Nielsen, J. W.
Powiązania:
https://bibliotekanauki.pl/articles/24201473.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
weather research and forecasting
search and rescue
operational ocean forecasting
European Satellite Systems
surface current
drifting sea surface temperature
European waters
Opis:
Maritime information services supporting European agencies such as the FRONTEX require European‐wide forecast solutions. Following a consistent approach, regional and global forecasts of the sea surface conditions from Copernicus Marine Service and national met‐ocean services are aggregated in space and time to provide a European‐wide forecast service on a common grid for the assistance of Search and Rescue operations. The best regional oceanographic model solutions are selected in regional seas with seamless transition to the global products covering the Atlantic Ocean. The regional forecast models cover the Black Sea, Mediterranean Sea, Baltic Sea, North Sea and combine the North Sea – Baltic Sea at the Danish straits. Two global models have been added to cover the entire model domain, including the regional models. The aggregated product is required to have an update frequency of 4 times a day and a forecasting range of 7 days, which most of the regional models do not provide. Therefore, smooth transition in time, from the shorter timerange, regional forecast models to the global model with longer forecast range are applied. The set of parameter required for Search and Rescue operations include sea surface temperature and currents, waves and winds. The current version of the aggregation method was developed for surface temperature and surface currents but it will be extended to waves in latter stages. The method relies on the calculation of aggregation weights for individual models. For sea surface temperature (SST), near real‐time satellite data at clear‐sky locations for the past days is used to determine the aggregation weights of individual forecast models. A more complicated method is to use a weighted multi‐model ensemble (MME) approach based on best forecast features of individual models and possibly including near real time observations. The developed method explores how satellite observations can be used to assess spatially varying, near real time weights of different forecasts. The results showed that, although a MME based on multiple forecasts only may improve the forecast, if the forecasts are unbiased, it is essential to use observations in the MME approach so that proper weights from different models can be calculated and forecast bias can be corrected. It is also noted that, in some months, e.g., June in Baltic Sea, even SST was assimilated, the forecast still show quite high error. There are also visible difference between different Copernicus Marine Environment Monitoring Service (CMEMS) satellite products, e.g. OSTIA and regional SST products, which can lead different forecast quality if different SST observation products are assimilated.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2023, 17, 3; 533--541
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Waves, Currents and Seabed Level Change in the Port of Gdynia During Extreme Events
Autorzy:
Sapiega, P.
Zalewska, T.
Wochna, A.
Powiązania:
https://bibliotekanauki.pl/articles/24201476.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
gulf of Gdansk
sea wave
hazard analysis
Harbour areas
transport from seabed
hydrodynamic effects
surface current
hydrodynamic model
Opis:
The primary purpose of the paper is to identify port areas most exposed to extreme hydrodynamic conditions (waves, sea currents, seabed level change). The results of modelling using SWAN wave model, MIKE 3D model, and reanalysis and measurement data were used in paper. Swell may exceed 0.8 m for winds exceeding 15 m s-1 from the west and south. During extreme conditions, sea currents can reach 0.4 ms-1 in the outer part of the bay adjacent to the port. Port basins do not show changes in the thickness of the seabed for the given maximum values of bottom currents. The most extensive deposition of the seabed and shore sediments (up to 0.04 m) is found on the Gdynia-Oksywie beach adjacent to the port and the approach fairway at the offshore currents. The outer area of the main breakwater is the most exposed to erosive activity (-0.012 m).
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2023, 17, 3; 515--521
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microplankton size structure induced by a warm-core eddy in the Western Bay of Bengal: Role of Trichodesmium abundance
Autorzy:
Chinnadurai, K.
Retnamma, J.
Nagarathinam, A.
Subramanian, P.R.
Singaram, P.
Shoba, S.
Powiązania:
https://bibliotekanauki.pl/articles/2078908.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
microplankton
size structure
biomass
Trichodesmium
sea surface temperature
wind
sea level
geostrophic current circulation
chlorophyll a
Bengal Bay
Opis:
Mesoscale warm-core eddies are common in the Bay of Bengal (BoB), and this study in the western BoB during Pre-Southwest Monsoon (April 2015) presents how a prolonged warmcore core eddy could modify the microplankton biomass and size structure. To investigate this, field sampling and laboratory analyses were augmented with satellite data sets of sea surface temperature (SST), winds, mean sea level anomaly (MSLA), geostrophic currents and chlorophyll-a. High SST with positive MSLA (≥ 20 cm) and a clockwise circulation, represented the occurrence of a large warm-core eddy in the western BoB. Time series data evidenced that it was originated in the mid of March and persistent there till early June, which in turn caused a decrease in the surface nutrients and chlorophyll-a. The abundance and biomass of microplankton were negligible in the warm-core eddy region. FlowCAM data showed a significant decrease in the autotrophic microplankton parameters in the warm-core eddy (av. 13 ± 9 ind. L−1 and 0.1 ± 0.04 μgC L−1, respectively) as compared to the surrounding locations (av. 227 ± 143 ind. L−1 and 0.8 ± 0.5 μgC L−1, respectively). Low nutrients level in the warm core eddy region favoured high abundance of needle-shaped phytoplankton cells dominated by Trichodesmium cells. As a result, the size of micro-autotrophs in the warm-core eddy was larger (av. 91,760 ± 12,902 μm3 ind.−1) than its outside (av. 50,115 ± 21,578 μm3 ind.−1). This is a deviation from our belief that the oligotrophy decreases the phytoplankton size. We showed here that the above understanding might not be infallible in warm-core eddies in the northern Indian Ocean due to its inducing effect on the Trichodesmium abundance.
Źródło:
Oceanologia; 2021, 63, 3; 283-300
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seasonal Variations of Sea Surface Temperature and Sea Current in the Celebes Sea
Autorzy:
Hapsari, Siti Nirmala
Syamsuddin, Mega Laksmini
Riyantini, Indah
Sunarto, Sunarto
Powiązania:
https://bibliotekanauki.pl/articles/1031483.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Celebes Sea
Sea Current
Sea Surface Temperature
Opis:
The waters of the Celebes Sea are an area that has quite complex dynamics because it is influenced by several factors, either regionally or globally. This influence certainly has an impact on variations in oceanographic conditions in waters such as Sea Surface Temperature (SST) and sea currents. Currently, there are many observations of oceanographic data, one of which is by using remote sensing methods. The purpose of this study was to determine the seasonal variations in sea surface temperature and sea surface currents in the Celebes Sea using a remote sensing system in a time series for 5 years (2014-2018). The results of this study indicate data on seasonal variation of SST and sea surface currents have an average maximum SST value for 5 years occurring in the eastern season and the second transitional season (May, June, July) with an average value range of 30.6 °C - 31.1 °C and the average maximum sea current velocity for 5 years occurs in the western monsoon with a value range of 0.72 m/s - 0.77 m/s. The high SST value and sea current velocity are caused by the influence of the season which causes variations in the ongoing rainfall, also presumably due to the opposite direction between the monsoon wind and the direction of the main current flowing in the Celebes Sea.
Źródło:
World News of Natural Sciences; 2021, 35; 135-143
2543-5426
Pojawia się w:
World News of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Driving forces of sandy sediment transport beyond the surf zone
Autorzy:
Stella, M.
Ostrowski, R.
Szmytkiewicz, P.
Kapinski, J.
Marcinkowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/47878.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
sandy sediment
sediment transport
surf zone
wave-current interaction
roughness
coastal zone
Baltic Sea
Źródło:
Oceanologia; 2019, 61, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thin chlorophyll layer concomitant of the thermohaline intrusion in the confluence of the Gulf Stream and Labrador Current (a case study)
Autorzy:
Karabashev, G.S.
Powiązania:
https://bibliotekanauki.pl/articles/48303.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
fluorometer
chlorophyll fluorescence
sea water
temperature
coloured dissolved organic matter
vertical distribution
thermohaline
sea water intrusion
Labrador Current
Źródło:
Oceanologia; 2019, 61, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Current observations from a looking down vertical V-ADCP: interaction with winds and tide? The case of Giglio Island (Tyrrhenian Sea, Italy)
Autorzy:
Cutroneo, L.
Ferretti, G.
Scafidi, D.
Ardizzone, G.D.
Vagge, G.
Capello, M.
Powiązania:
https://bibliotekanauki.pl/articles/47976.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
wind
tide
interaction
sea level
normalized cross-correlation function
wind velocity
current measurement
Giglio Island
Tyrrhenian Sea
Italy
Opis:
In the context of the environmental monitoring of the Concordia wreck removal project, measurements of currents, winds and sea level height were made along the eastern coast of the Giglio Island, Tyrrhenian Sea (Italy), during 2012—2013. The aim of the study was to investigate the effect of atmospheric forcing and periodic sea-level changes on the coastal currents. Normalised Cross-Correlation Function analysis allowed us to correlate these observations. A marked inter-seasonal variability was found in both current and local wind velocity observations but a significant level of correlation between the data was only found during strong wind events. Current and wind directions appeared to be uncorrelated and current measurements showed a predominant NW—SE direction, presumably linked to the shape and orientation of Giglio Island itself. During strong winds from the SSE, current flow was towards the NNW but it suddenly switched from the NNW to the SE at the end of wind events. The results show that, at Giglio Island, currents are principally dominated by the general cyclonic Tyrrhenian circulation, and, secondly, by strong wind events. The sea level had no effects on the current regime.
Źródło:
Oceanologia; 2017, 59, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sediment transport beyond the surf zone under waves and currents of the non-tidal sea: Lubiatowo (Poland) case study
Autorzy:
Ostrowski, R.
Stella, M.
Powiązania:
https://bibliotekanauki.pl/articles/241109.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
wave-induced nearbed oscillations
sea currents
wind-driven current
sand grain diameter
bed shear stress
friction velocity
sediment transport
Opis:
The paper deals with the sandy coastal zone at Lubiatowo in Poland (the south Baltic Sea). The study comprises experimental and theoretical investigations of hydrodynamic and lithodynamic processes in the coastal region located close to the seaward boundary of the surf zone and beyond the surf zone. The analysis is based on field data collected at the IBW PAN Coastal Research Station in Lubiatowo. The data consist of wind velocity reconstructed from the long-term wave climate, deep-water wave buoy records and sea bottom soil parameters. Nearbed flow velocities induced by waves and currents, as well as bed shear stresses are theoretically modelled for various conditions to determine sediment motion regimes in the considered area. The paper discusses the possibility of occasional intensive sediment transport and the occurrence of distinct sea bed changes at bigger water depths.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2016, 63, 1; 63-77
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variability of currents over the southern slope of the Gulf of Finland
Autorzy:
Suhhova, I.
Pavelson, J.
Lagemaa, P.
Powiązania:
https://bibliotekanauki.pl/articles/48946.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
stratification
upwelling
downwelling
Finland Gulf
coastal sea water
seasonal thermocline
current velocity
Źródło:
Oceanologia; 2015, 57, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formation and species composition of stormcast beach wrack in the Gulf of Riga, Baltic Sea
Autorzy:
Suursaar, U.
Torn, K.
Martin, G.
Herkul, K.
Kullas, T.
Powiązania:
https://bibliotekanauki.pl/articles/48538.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
beach wrack
species composition
wave
current
storm
hydrodynamic modelling
submerged vegetation
biodiversity
Riga Gulf
Baltic Sea
Źródło:
Oceanologia; 2014, 56, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of landfast ice on the hydrography and circulation of the Baltic Sea coastal zone
Autorzy:
Merkouriadi, I.
Lepparanta, M.
Powiązania:
https://bibliotekanauki.pl/articles/49047.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Finland Gulf
hydrography
landfast ice
circulation
Baltic Sea
coastal zone
water temperature
salinity
current
Źródło:
Oceanologia; 2013, 55, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the possibility of convective overturning in the Slupsk Furrow overflow of the Baltic Sea
Autorzy:
Zhurbas, V.
Elken, J.
Paka, V.
Piechura, J.
Chubarenko, I.
Vali, G.
Golenko, N.
Shchuka, S.
Powiązania:
https://bibliotekanauki.pl/articles/48298.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Baltic Sea
deep water
dense water
density stratification
gravity current
numerical simulation
saline water
Slupsk Furrow
transverse circulation
water mass
Opis:
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.
Źródło:
Oceanologia; 2011, 53, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Waves, currents and sea level variations along the Letipea - Sillamäe coastal section of the Southern Gulf of Finland
Autorzy:
Suursaar, U.
Powiązania:
https://bibliotekanauki.pl/articles/48913.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
wave
variation
hydrodynamic condition
measurement
Doppler current prolifer
calibration
semi-empirical hindcast
water parameter
upwelling
coastal jet
climate change
Baltic Sea
Letipea-Sillamae coastal section
Finland Gulf
Opis:
Variations in the hydrodynamic conditions were studied on the basis of 336 days of measurements with a Doppler current profiler. With wave data as a calibration reference, a semi-empirical hindcast of wave parameters is presented in the fetch- limited near-shore area for the period 1966–2008. A resultant 4–6 cm s−1 westward current dominated along the coast. Occasional fast sub-surface westward currents under modest wind forcing, as well as asymmetrical vertical profiles for westward and eastward currents indicated the influence of upwelling-related baroclinic coastal jets. The average frequency of upwelling was estimated at 17%; some of the events were identified in near-homothermic winter conditions on the basis of salinity and multi-layer flow records. While the mean sea level trend at Narva-Jõesuu roughly approximated the global estimates for 1899–2009, the annual maximum sea level increase was 5–8 mm yr−1. Both mean and maximum wave heights declined as a result of decreasing winds from the north.
Źródło:
Oceanologia; 2010, 52, 3; 391-416
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
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

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