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Wyszukujesz frazę "variability" wg kryterium: Temat


Tytuł:
Observed variability in physical and biogeochemical parameters in the Central Arabian Gulf
Autorzy:
Rakib, F.
Al-Ansari, E.M.A.S.
Husrevoglu, Y.S.
Yigiterhan, O.
Al-Maslamani, I.
Aboobacker, V.M.
Vethamony, P.
Powiązania:
https://bibliotekanauki.pl/articles/2078929.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
economic zone
Arabian Gulf
vertical variability
spatial variability
temporal variability
water column
dissolved oxygen
hydrography
chlorophyll a
Opis:
In situ measurements of physical and biogeochemical variables were conducted along a transect in the Exclusive Economic Zone (EEZ) of Qatar during late summer (September 2014) and winter (January 2015) to investigate their vertical, spatial and temporal variability. The study reveals that the water column is characterized by strong stratification during late summer in the deepest station, where the water depth is around 65 m and the surface to bottom temperature variation is around 9.1°C. The water column is vertically homogeneous during winter due to surface cooling and wind mixing. The surface to 23 m water column is characterized by ample dissolved oxygen (DO) during late summer and winter in the offshore regions, however, relatively low DO is found during late summer due to weak mixing and advection under weak winds and currents. Dissolved oxygen drops to hypoxic levels below the summer thermocline, and the winter high DO layer extends up to the bottom. Chlorophyll-a (Chl-a) is relatively high during late summer in the offshore region, while that in the nearshore regions is very low, which is linked to the anthropogenic stresses from the central east coast of Qatar. The results identified in this study fill an essential gap in the knowledge of regional primary production dynamics.
Źródło:
Oceanologia; 2021, 63, 2; 227-237
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrogeochemistry and magnitude of SGD in the Bay of Puck, Southern Baltic Sea
Autorzy:
Klostowska, Z.
Szymczycha, B.
Lengier, M.
Zarzeczanska, D.
Dzierzbicka-Glowacka, L.
Powiązania:
https://bibliotekanauki.pl/articles/47678.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
hydrogeochemistry
submarine groundwater discharge
seasonal variability
spatial variability
Puck Bay
Baltic Sea
Źródło:
Oceanologia; 2020, 62, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Validation and statistical analysis of the group for high resolution sea surface temperature data in the Arabian Gulf
Autorzy:
Nesterov, O.
Temimi, M.
Fonseca, R.
Nelli, N.R.
Addad, Y.
Bosc, E.
Abida, R.
Powiązania:
https://bibliotekanauki.pl/articles/2078874.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
validation
statistical analysis
sea surface temperature
annual variability
seasonal variability
Arabian Gulf
Oman Sea
Opis:
The combined effect of climate change and steadily increasing seawater demand for industrial and domestic purposes in the Arabian Gulf region has a significant impact on the ecosystem in this region. Additionally, this effect may reduce the efficiency and increase the operating costs of industrial facilities that utilize seawater for cooling and other purposes. In this context, it is important to know various statistical characteristics of the sea surface temperature (SST) and their trends, in addition to the mean climatological characteristics. The analysis conducted in this study utilized a 17-year Group for High Resolution Sea Surface Temperature Level 4 dataset of 0.01 × 0.01° spatial resolution. First, the dataset was compared against a 2-year seawater temperature measurements at the ten offshore buoys in the relatively shallow coastal waters of the United Arab Emirates between Ras Ghumais and Dubai, which showed a reasonably good agreement between the two datasets, with the estimated root mean square deviations ranging from 0.5 to 0.9°C. Subsequently, several statistical SST characteristics were calculated. The trend analysis showed not only positive tendencies in the mean SSTs of up to 0.08°C/year in the northern Gulf, but also the trends in the annual percentile exceedances, particularly the 95th percentiles (near-maximum SSTs), which increased by approximately 0.07°C/year in the western United Arab Emirates and eastern Qatar waters. On the contrary, the 5th percentiles (near-minimum SSTs) decreased by up to 0.1°C/year, especially in the waters around Bahrain, Qatar, and the western United Arab Emirates. These results indicate that extreme hot and cold SST events in the Gulf are becoming more frequent and more extreme than before.
Źródło:
Oceanologia; 2021, 63, 4; 497-515
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial and temporal variability of sea surface temperature in the Baltic Sea based on 32-years (1982–2013) of satellite data
Autorzy:
Stramska, M.
Bialogrodzka, J.
Powiązania:
https://bibliotekanauki.pl/articles/48273.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
satellite data
sea surface temperature
Baltic Sea
annual cycle
climate change
spatial variability
temporal variability
Źródło:
Oceanologia; 2015, 57, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variability in the saline water exchange between the Baltic and the Gulf of Gdańsk by the σ-coordinate model
Autorzy:
Jankowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/48078.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
coastal zone
variability
thermohaline variability
water exchange
saline water
Baltic Sea
mass exchange
Gdansk Gulf
Opis:
A three-dimensional baroclinic σ–coordinate model was applied to study the circulation and thermohaline variability in the coastal zone in the south-eastern Baltic Sea. The model is based on the Princeton Ocean Model code of Blumberg & Mellor (1987), known as POM, and has the horizontal resolution of ∼5 km and 24 σ-levels in the vertical. The hydrodynamic conditions and variability of water and salt exchange between the Gulf of Gdańsk and the Baltic Proper, and the renewal of water masses in the Gulf of Gdańsk due to atmospheric forcing are analyzed. The numerical simulations were performed with real atmospheric forcings as well as with homogeneous (spatially uniform) wind fields over the whole Baltic Sea. The numerical simulations showed that the atmospheric forcing (winds) can play a significant role in shaping the renewal of bottom saline waters in the Gulf of Gdańsk. Two regions of inflow/outflow of saline waters responsible for the salinity regime were located. The overall water exchange between the Gulf and the Baltic Proper as well as the exchange of saline bottom waters appear to be strongly dependent on wind conditions. The net flux of water of salinity >9 PSU is of the order of 48 000–100000 m3 s−1. SE, E, S and NE winds were found to exert the greatest influence on salinity conditions in the Gulf of Gdańsk. Estimates of saline (salinity >9 PSU) water residence time based on the model simulation yielded values from 46 days for SE winds to 153 days for NW winds.
Źródło:
Oceanologia; 2003, 45, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of tides and waves on near-surface suspended sediment concentrations in the English Channel
Autorzy:
Guillou, N.
Rivier, A.
Chapalain, G.
Gohin, F.
Powiązania:
https://bibliotekanauki.pl/articles/48548.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
suspended sediment concentration
spatial variability
temporal variability
coastal water
English Channel
bathymetry
numerical modelling
ROMS model
MERIS data
Opis:
Numerous ecological problems of continental shelf ecosystems require a refined knowledge of the evolution of suspended sediment concentrations (SSC). The present investigation focuses on the spatial and temporal variabilities of near-surface SSC in coastal waters of the English Channel (western Europe) by exploiting numerical predictions from the Regional Ocean Modeling System ROMS. Extending previous investigations of ROMS performances in the Channel, this analysis refines, with increased spatial and temporal resolutions, the characterization of near-surface SSC patterns revealing areas where concentrations are highly correlated with evolutions of tides and waves. Significant tidal modulations of near-surface concentrations are thus found in the eastern English Channel and the French Dover Strait while a pronounced influence of waves is exhibited in the Channel Islands Gulf. Coastal waters present furthermore strong SSC temporal variations, particularly noticeable during storm events of autumn and winter, with maximum near-surface concentrations exceeding 40 mg l1 and increase by a factor from 10 to 18 in comparison with time-averaged concentrations. This temporal variability strongly depends on the granulometric distribution of suspended sediments characterized by local bimodal contributions of silts and sands off coastal irregularities of the Isle of Wight, the Cotentin Peninsula and the southern Dover Strait.
Źródło:
Oceanologia; 2017, 59, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variability in aerosol optical properties at Hornsund, Spitsbergen
Autorzy:
Rozwadowska, A.
Sobolewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/48390.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Hornsund
Spitsbergen
aerosol optical property
atmosphere
chemical composition
humidity
meteorological condition
seasonal variability
variability
wind direction
wind speed
Arctic aerosol
Źródło:
Oceanologia; 2010, 52, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solar radiation at the surface in the Baltic Proper
Autorzy:
Keevallik, S.
Loitjarv, K.
Powiązania:
https://bibliotekanauki.pl/articles/47457.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Baltic Sea
atmosphere
marine biology
photosynthesis
phytoplankton bloom
radiation
solar radiation
spatio-temporal variability
temporal variability
water body
water surface
Opis:
Radiation data recorded at 12 sites around the central part of the Baltic Sea during 1996–2000 drawn from the BALTEX (Baltic Sea Experiment) meteorological data archives are used to study the spatio-temporal variability of daily global radiation totals. The annual average daily global radiation total varies from about 10MJ m−2 at Visby (on Gotland) and Kołobrzeg (on the coast of Poland) to less than 9 MJ m−2 at Z¯ıl¯ani (inland Latvia), ˇ Silut˙e (Lithuania) and Jokioinen (Finland). The monthly average daily global radiation total over the whole region extends from 0.93 in December to 19.0 in June. The variability in global radiation is analysed on the basis of the fraction of the daily total at the top of the atmosphere. The spatial and temporal variability is the least in August – this shows that the variation in the cloud cover and atmospheric properties at this time of year is the smallest. The spatial correlation is the strongest between the two Finnish stations – Vantaa and Jokioinen. It is also high between Stockholm and Norrk¨oping, on the east coast of Sweden. The correlation coefficients are the largest over the whole area in April. Radiation data from coastal stations are compared with an earlier parameterization based on ship observations (Rozwadowska & Isemer 1998, Isemer & Rozwadowska 1999). It is concluded that in climatological research, actinometric data from Visby can be used to characterize the radiation field over the northern part of the Baltic Proper and those from Kołobrzeg to characterize the adiation field over the southern part of this sea.
Źródło:
Oceanologia; 2010, 52, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorptive properties of natural water surfactant films. Dead Vistula catchment water studies
Autorzy:
Pogorzelski, S.J.
Kogut, A.D.
Powiązania:
https://bibliotekanauki.pl/articles/48236.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
temporal variability
natural water
inland water
natural film
surface isotherm
scaling procedure
spatial variability
surfactant
adsorption kinetics
Vistula River
catchment area
Opis:
The paper contains the results of natural film experiments carried out on inland waters in the Dead Vistula (Martwa Wisła) catchment area during 1999–2002 using the integrated Langmuir trough-Wilhelmy plate system,w hich ‘cuts out’ an undisturbed film-covered area without any physicochemical sample processing. The static film parameters result from the generalized scaling procedures applied to the surface pressure-area isotherms. They appear to correspond well to observations of the film composition (Alim, MW, Eisoth),film solubility and the miscibility of its components (via R, ΔSc and y factors),and surface concentration (πeq, Γeq). A novel approach is presented for the adsorption dynamics on the basis of the mixed kinetic-diffusion model and analyses of the dynamic surface pressure plots,whic h leads to the determination of the effective relative diffusion coefficient Deff/D and activation energy barrier Ea/RT . There is reason to believe that certain classes of film-forming components or ‘end-members’ may dominate the static and dynamic surface properties. Some of these substances can be used as source-specific surface-active biomarkers to trace temporal and spatial changes due to environmental factors or the production of biological matter. The concept was tested for the Dead Vistula river and its tributaries. The results demonstrate that natural films are a complex mixture of biopolymeric molecules covering a wide range of solubilities,sur face activities and molecular masses with an apparent structural film architecture. Such studies could lead to the development of film structure parameters – indicators of ecosystem quality and the state of the environment.
Źródło:
Oceanologia; 2003, 45, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monitoring the effect of upwelling on the chlorophyll a distribution in the Gulf of Finland (Baltic Sea) using remote sensing and in situ data
Autorzy:
Uiboupin, R.
Laanemets, J.
Sipelgas, L.
Raag, L.
Lips, I.
Buhhalko, N.
Powiązania:
https://bibliotekanauki.pl/articles/48503.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
spatio-temporal variability
chlorophyll a
distribution
variability
upwelling
Baltic Sea
Finland Gulf
sea surface temperature
remote sensing
spatial distribution
ecological status
satellite image
Opis:
The spatio-temporal variability of chlorophyl a (Chl a) caused by a sequence of upwelling events in the Gulf of Finland in July–August 2006 was studied using remote sensing data and field measurements. Spatial distributions of sea surface temperature (SST) and Chl a concentration were examined using MODIS and MERIS data respectively. The MERIS data were processed with an algorithm developed by the Free University of Berlin (FUB) for case 2 waters. Evaluation of MERIS Chl a versus in situ Chl a showed good correlation (r2 = 0.67), but the concentration was underestimated. The linear regression for a 2 h window was applied to calibrate MERIS Chl a. The spatio-temporal variability exhibited the clear influence of upwelling events and related filaments on Chl a distribution in the western and central Gulf. The lowest Chl a concentrations were recorded in the upwelled water, especially at the upwelling centres, and the highest concentrations (13 mg m−3) were observed about two weeks after the upwelling peak along the northern coast. The areas along the northern coast of upwelled water (4879 km2) on the SST map, and increased Chl a (5526 km2) two weeks later, were roughly coincident. The effect of upwelling events was weak in the eastern part of the Gulf, where Chl a concentration was relatively consistent throughout this period.
Źródło:
Oceanologia; 2012, 54, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indian Ocean wind speed variability and global teleconnection patterns
Autorzy:
Sinha, M.
Jha, S.
Chakraborty, P.
Powiązania:
https://bibliotekanauki.pl/articles/2079299.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
wind speed
variability
sea surface temperature
remote sensing
Indian Ocean
Opis:
The influence of the local sea surface temperature (SST) and remote ENSO (El Niño-Southern Oscillation) indices on the wind speed (WS) data were explored for the Indian Ocean region. Relationships among the parameters were studied using spatial correlation plots and significant correlation ranges. Two months (July and January) representing opposite monsoon phases were selected for analysis for the period 1950–2016. There was a significant negative correlation between WS and SST over the Bay of Bengal (BOB) during July. Although different ENSO indices correlated differently in different areas of the Indian Ocean, the region off the coast of Sri Lanka was most significantly teleconnected. The southwest monsoon locally impacted the WS and SST relationship and the WS parameter was remotely teleconnected in both the monsoon seasons. Further empirical orthogonal function (EOF) analysis was applied on the 67 years WS data of the BOB region to extract the dominant mode representing maximum variability of the total variance. The temporal pattern of the first principal component (PC1) of WS data was linked to the North Atlantic Oscillations in January and the Atlantic Multidecadal Oscillation in July respectively. The continuous wavelet power spectra of the PC1 of WS showed significant regions in the 2–4-year band resembling the ENSO variability. Wavelet coherence applied between PC1 of WS and the ENSO indices showed greatest values for January in the 8–16-year band and for July in the 0–4-year band. A close relationship was established between the WS variability in BOB and the ENSO indices.
Źródło:
Oceanologia; 2020, 62, 2; 126-138
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial variability of recent sedimentation rates in the Eastern Gotland Basin (Baltic Sea)
Autorzy:
Hille, S.
Leipe, T.
Seifert, T.
Powiązania:
https://bibliotekanauki.pl/articles/48484.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
hydrography
Gotland Basin
sediment accumulation
spatial variability
sedimentation rate
Baltic Sea
Opis:
In order to study recent sedimentation rates in the Eastern Gotland Basin, 52 short sediment cores collected from the deepest part (<150 m)of the Basin in 2003 were investigated. The upper parts of all the cores were distinctly laminated and dark in colour, followed by a homogeneous, greyish lower part. The thickness of the laminated sequences varied from 17 to 300 mm. 210Pb dating analyses of selected cores revealed that the change from non-laminated to laminated sediments happened about 100 years ago, indicating a shift from predominantly oxic bottom water conditions to anoxic conditions. Used as a time marker, this shift in the sediment texture enabled sediment accumulation rates to be estimated for all sediment cores. The observed mean linear sedimentation rate for the whole basin was 0.93 ± 0.67 mm yr−1. The respective bulk sediment accumulation rates ranged from 10.5 to 527 g m−2 yr−1 with an average of 129 ± 112 g m−2 yr−1, indicating a high spatial variability of sedimentation rates within the basin. This agrees very well with the long-term sedimentation pattern since the Litorina transgression. The observed pattern clearly reflects the hydrographic conditions at the seafloor as studied by modelled near-bottom current velocities.
Źródło:
Oceanologia; 2006, 48, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigating the role of air-sea forcing on the variability of hydrography, circulation, and mixed layer depth in the Arabian Sea and Bay of Bengal
Autorzy:
Srivastava, A.
Dwivedi, S.
Mishra, A.K.
Powiązania:
https://bibliotekanauki.pl/articles/48693.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
seasonal variability
hydrography
circulation
Arabian Sea
Bengal Bay
general circulation model
Źródło:
Oceanologia; 2018, 60, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of environmental variables on midsummer dinoflagellate community in the Neva Estuary (Baltic Sea)
Autorzy:
Golubkov, M.
Nikulina, V.
Golubkov, S.
Powiązania:
https://bibliotekanauki.pl/articles/48841.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
dinoflagellate
phytoplankton
eutrophication
environmental variability
climate change
Neva Estuary
Baltic Sea
Źródło:
Oceanologia; 2019, 61, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diurnal variability of water vapour in the Baltic Sea region according to NCEP-CFSR and BaltAn65plus reanalyses
Autorzy:
Jakobson, E.
Keernik, H.
Luhamaa, A.
Ohvril, H.
Powiązania:
https://bibliotekanauki.pl/articles/49169.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
water vapour
diurnal variability
precipitation water
temperature
evaporation
humidity
Baltic Sea
Źródło:
Oceanologia; 2014, 56, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł

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