Temat: temporal variability - Katalog OPAC zbiorów

Skocz do pozycji: 1.

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

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Skocz do pozycji: 2.

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

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Skocz do pozycji: 3.

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

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Skocz do pozycji: 4.

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

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Skocz do pozycji: 5.

Tytuł:: Recent multiyear trends in the Baltic Sea level
Autorzy:: Stramska, M.
Chudziak, N.
Powiązania:: https://bibliotekanauki.pl/articles/47655.pdf
Data publikacji:: 2013
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: Baltic Sea
sea level
climate change
spatial heterogeneity
multilayer system
temporal variability
coastal management
eutrophication
Źródło:: Oceanologia; 2013, 55, 2
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Unravelling the spatio-temporal variation of zooplankton community from the river Matla in the Sundarbans Estuarine System, India
Autorzy:: Nandy, T.
Mandal, S.
Powiązania:: https://bibliotekanauki.pl/articles/2079187.pdf
Data publikacji:: 2020
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: zooplankton
Copepoda
bioindicator
spatio-temporal variability
ecosystem functioning
seasonal fluctuation
estuarine water
Indian Sundarban
hydrographic change
Opis:: Zooplankton is an important bioindicator of ecosystem functioning. Knowledge of the seasonal fluctuation in the zooplankton population in estuarine waters of the Indian Sundarbans is rather limited. In the present study, we analysed the community structure of zooplankton assemblages and their spatio-temporal variations based on different multivariate statistics and indicator value analysis. A total of 56 taxa were identified and the density was primarily dominated by planktonic copepods and few meroplankton communities during four sampling seasons. The most abundant species were: Acartia spinicauda, Acartia sp., Bestiolina similis, Euterpina acutifrons, Labidocera acuta, Paracalanus aculeatus, Paracalanus parvus and Paracalanus indicus. Canonical Correspondence Analysis highlighted that temperature, pH, DO, salinity and nutrients were the prevailing environmental parameters associated with significant spatio-temporal changes of zooplankton distribution in this area. The highest abundance of zooplankton was recorded in winter, followed by monsoon, summer and spring. Throughout the study period, different zooplankton indices were observed in good condition. Seasonal occurrence of dominant zooplankton with high IndVal index was markedly observed and it might be used as a potential bioindicator for a particular season and environmental condition in this estuarine complex. The results of this study provide evidence for the presence of warm water species in the estuarine waters of the Indian Sundarbans and can be a clear indication of climate change-mediated elevated temperature in the estuarine system. Our results underscore the high diversity of zooplankton from mangrove dominated estuarine complex and emphasize the need for long-term monitoring in ecologically fragile ecosystems like the Sundarbans Estuarine System.
Źródło:: Oceanologia; 2020, 62, 3; 326-346
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Spatio-temporal variability in the Brazil-Malvinas Confluence Zone (BMCZ), based on spectroradiometric MODIS-AQUA chlorophyll-a observations
Autorzy:: Telesca, L.
Pierini, J.O.
Lovallo, M.
Santamaria-del-Angel, E.
Powiązania:: https://bibliotekanauki.pl/articles/48518.pdf
Data publikacji:: 2018
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: confluence zone
environmental variation
sea water
phytoplankton
spatio-temporal variability
chlorophyll a
ocean colour
remote sensing
Opis:: The Brazil–Malvinas Confluence Zone (BMCZ) is characterized by high environmental variation, which could be reflected in several optical types of water, from one containing only phytoplankton and sea water to other optically more complex. In this paper, we analyze the spatio-temporal variability of the Chlorophyll-a detected by the ocean color sensor (CHLAsat) in BMCZ in order to understand its environmental variability. We use the MODIS-Aqua CHLAsat monthly composites imagery from 2002 to 2015, and applied two statistical methods: the correlogram-based robust periodogram to identify, over a broad spectrum of temporal, the most significant periodicities, and the pixel gradient distribution to study the spatial-temporal gradients within the BMCZ and variations over the continental shelf and coastal waters. Our results point out to the predominance of the annual cycle over most of the investigated area, although an area from latitude 37°S in direction NE, alongshore of Uruguay to Brazil, evidences interannual periodicities, possibly related to variations in the discharge of the Rio de la Plata associated with the El Niño phenomena. The ocean color spectroradiometric signature in terms of pixel gradient presents a relatively high variability (∼0.0 to 0.65 mg m−3); in particular the high values of the pixel gradient correspond to saline front of the estuarine system of Rio de la Plata, and to the strip of the platform that extends along the isobaths of 80 m (coast of Uruguay), especially in the center and south of the study area.
Źródło:: Oceanologia; 2018, 60, 1
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Spatio-temporal variation of microphytoplankton in the upwelling system of the South-Eastern Arabian Sea during the summer monsoon of 2009
Autorzy:: Thomas, L.C.
Padmakumar, K.B.
Smitha, B.R.
Asha Devi, C.R.
Nandan, S.B.
Sanjeevan, V.N.
Powiązania:: https://bibliotekanauki.pl/articles/49085.pdf
Data publikacji:: 2013
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: Arabian Sea
upwelling
coastal water
phytoplankton
chlorophyll a
diatom
centric diatom
spatio-temporal variability
microphytoplankton
Chaetoceros
Źródło:: Oceanologia; 2013, 55, 1
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Spatio-temporal variability of the phytoplankton biomass in the Levantine basin between 2002 and 2015 using MODIS products
Autorzy:: El Hourany, R.
Fadel, A.
Gemayel, E.
Abboud-Abi Saab, M.
Faour, G.
Powiązania:: https://bibliotekanauki.pl/articles/48550.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: spatio-temporal variability
phytoplankton biomass
remote sensing
sea surface temperature
chlorophyll a concentration
phytoplankton bloom
Mediterranean Sea
Opis:: The Levantine basin in the Eastern Mediterranean Sea is subject to spatial and seasonal variations in primary production and physical-chemical properties both on a short and long-term basis. In this study, the monthly means of daily MODIS product images were averaged between 2002 and 2015, and used to characterize the phytoplankton blooms in different bioregions of the Levantine basin. The selected products were the sea surface temperature (SST), the chlorophyll-a concentration (Chl-a), the diffuse attenuation coefficient for downwelling irradiance at 490 nm (Kd_490) and the colored dissolved organic matter index (CDOM_ index). Our results showed that phytoplankton blooms were spatially and temporally variable. They occurred in late autumn at the Nile Delta, in early spring and late summer at the eastern coastline, and in spring at the northeastern coastline. The northern coastline and the open water had a common bloom occurring in winter. The Nile Delta was found to be the most productive area of the Levantine basin showing high Chl-a. Kd_490 and Chl-a present a parallel co-variation indicating a dominance of Case 1 waters in the Levantine basin. The CDOM_index shows a phase shift with the Chl-a fluctuation. A strong inverse correlation was observed between both Chl-a and CDOM_index with SST, connoting an indirect relation represented by a depression of CDOM in summer by photobleaching, and a suppression of the chlorophyll-a concentration due to water stratification, together with nutrient stress. An overestimation of the Chl-a values had been signaled by the use of the CDOM_index, suggesting a correction plan in a latter study.
Źródło:: Oceanologia; 2017, 59, 2
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

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

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Skocz do pozycji: 11.

Tytuł:: Spatio-temporal variability of the size-fractionated primary production and chlorophyll in the Levantine Basin (Northeastern Mediterranean)
Autorzy:: Yucel, N.
Powiązania:: https://bibliotekanauki.pl/articles/48586.pdf
Data publikacji:: 2018
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: spatio-temporal variability
primary production
chlorophyll a
phytoplankton
ecosystem
nutrient analysis
temperature
salinity
principal component analysis
Mediterranean Basin
Źródło:: Oceanologia; 2018, 60, 3
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Spatio-temporal variations in sulfur-oxidizing and sulfate-reducing bacterial activities during upwelling, off South-West coast of India
Autorzy:: Kamaleson, A.S.
Gonsalves, M.-J.
Kumar, S.
Jineesh, V.K.
LokaBharathi, P.A.
Powiązania:: https://bibliotekanauki.pl/articles/47551.pdf
Data publikacji:: 2019
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: spatio-temporal variability
sulphate reduction
sulphur oxidation
bacterial activity
microbial degradation
environment parameter
upwelling
Arabian Sea
India
coastal water
Źródło:: Oceanologia; 2019, 61, 4
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

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

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Skocz do pozycji: 14.

Tytuł:: Chromophoric dissolved organic matter (CDOM) variability over the continental shelf of the Northern Bay of Bengal
Autorzy:: Das, S.
Das, I.
Giri, S.
Chanda, A.
Maity, S.
Lotliker, A.A.
Kumar, T.S.
Akhand, A.
Hazra, S.
Powiązania:: https://bibliotekanauki.pl/articles/48552.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: chromophoric dissolved organic matter
absorption coefficient
sea surface
salinity
chlorophyll a
total suspended matter
spatio-temporal variability
Bengal Bay
continental shelf
Opis:: The present paper dealt with the annual dynamics of the absorption coefficient of chromophoric dissolved organic matter at 440 nm {aCDOM(440)} during February 2015 to January 2016 in the continental shelf of northern Bay of Bengal (nBoB) for the first time. Sea surface salinity (SSS), chlorophyll-a (Chl-a), total suspended matter (TSM) were also analyzed. It was hypothesized that CDOM should exhibit significant spatial and temporal variability in this region. aCDOM(440) and spectral slope ranged between 0.1002 m1—0.6631 m1 and 0.0071 nm1— 0.0229 nm1 respectively during the entire study period. Higher values of aCDOM(440) were observed in the near shore stations and gradually decreased towards the offshore. Significant seasonal variability of aCDOM(440) was observed between the monsoon and non-monsoon seasons ( p < 0.05). Thus the framed hypothesis was successfully accepted by means of the present study. The CDOM was mainly found to be of allochthonous character in this region. aCDOM(440) portrayed a significant negative linear relationship with SSS (R2 = 0.80; p < 0.05) implying conservative mixing of marine and terrestrial end members. However, examining the spatial variability of the relationship, it was observed that this relationship was significant only in the nearshore stations. While examining the seasonal variability of this relationship, it was found to be most significant during the monsoon (R2 = 0.81; p < 0.05). Thus it was inferred that whenever the SSS gradient was higher, the relationship between aCDOM(440) and SSS was found to be most significant.
Źródło:: Oceanologia; 2017, 59, 3
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki