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Wyszukujesz frazę "spatio-temporal variability" wg kryterium: Temat


Tytuł:
Spatiotemporal variation of biochemical composition of organic matter and number of bacteria in core sediments of selected beaches of the southern Baltic Sea
Czasowa i przestrzenna zmienność biochemicznego składu materii organicznej i liczby bakterii w osadach wybranych plaż południowego Morza Bałtyckiego
Autorzy:
Bigus, K.
Astel, A.
Stec, M.
Piskula, P.
Tematy:
spatio-temporal variability
biochemical composition
organic matter
bacteria number
sediment
beach
Baltic Sea
Pokaż więcej
Wydawca:
Akademia Pomorska w Słupsku
Powiązania:
https://bibliotekanauki.pl/articles/85083.pdf  Link otwiera się w nowym oknie
Opis:
Sandy sediments coming from three beaches of the southern Baltic Sea were collected and analyzed. Investigated beaches were divided according to strength of anthropogenic impact and degree of sheltering. The first beach was situated in Ustka on the eastern side of the mouth of the Słupia River, second in Czołpino and the last one in Puck. Core sediment samples were collected seasonally, depending on the influence of the sea water on the examined sediments. At each station, surface sediments (0-5 cm) were collected as well as sediments at the depth of 10-15 cm. The general content of organic matter, proteins, lipids, carbohydrates, organic carbon and total bacterial number were determined. The results of the conducted tests reveal, that anthropopressure, degree of sheltering, the depth where the collected sediments were taken and the direct influence of the sea water on the sediments have impact on the chemical composition of organic matter and bacterial number in beach sediments.
Pobierano i analizowano piaszczyste osady pochodzące z trzech plaż południowego Bałtyku, które zostały podzielone na podstawie wpływu antropopresji i stopnia osłonięcia plaży. Pierwsza plaża położona była w Ustce we wschodniej części ujścia rzeki Słupi, druga w Czołpinie, a ostatnia w Pucku. Próbki osadów plażowych zbierano sezonowo, w zależności od wpływu wody morskiej na badane osady. Na każdym stanowisku pobierano osady powierzchniowe (0-5 cm), a także osady na głębokości 10-15 cm. Określono zawartość materii organicznej, białek, lipidów, węglowodanów, węgla organicznego i całkowitej liczby bakterii. Wyniki przeprowadzonych badań wykazały, że antropopresja, stopień osłonięcia plaży, głębokość pobieranych osadów i bezpośredni wpływ wody morskiej na osady oddziałują na skład chemiczny materii organicznej i liczbę bakterii w osadach plażowych.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unravelling the spatio-temporal variation of zooplankton community from the river Matla in the Sundarbans Estuarine System, India
Autorzy:
Nandy, T.
Mandal, S.
Tematy:
zooplankton
Copepoda
bioindicator
spatio-temporal variability
ecosystem functioning
seasonal fluctuation
estuarine water
Indian Sundarban
hydrographic change
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/2079187.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
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.
Tematy:
confluence zone
environmental variation
sea water
phytoplankton
spatio-temporal variability
chlorophyll a
ocean colour
remote sensing
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Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/48518.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solar radiation at the surface in the Baltic Proper
Autorzy:
Keevallik, S.
Loitjarv, K.
Tematy:
Baltic Sea
atmosphere
marine biology
photosynthesis
phytoplankton bloom
radiation
solar radiation
spatio-temporal variability
temporal variability
water body
water surface
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Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/47457.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
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.
Tematy:
spatio-temporal variability
phytoplankton biomass
remote sensing
sea surface temperature
chlorophyll a concentration
phytoplankton bloom
Mediterranean Sea
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Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/48550.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geostatistical Analysis of Spatio-Temporal Variability of Soil Microbial Biomass and Its Activity Field at a Plot Scale
Analiza geostatystyczna zmienności czasoweo-przestrzennej glebowej biomasy mikrobiologicznej I jej aktywności w skali poletkowej
Autorzy:
Piotrowska-Długosz, A.
Charzyński, P.
Tematy:
zmienność czasowo-przestrzenna
geostatystyka
biomasa mikrobiologiczna
hydroliza
spatio-temporal variability
geostatistics
soil microbial biomass
FDA hydrolysis
dehydrogenase
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Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Powiązania:
https://bibliotekanauki.pl/articles/389050.pdf  Link otwiera się w nowym oknie
Opis:
Analysis and interpretation of spatio-temporal variability of soil microbial biomass content (microbial biomass carbon – MBC and nitrogen – MBN) and activity (dehydrogenase – DH, and fluorescein diacetate hydrolysis – FDAH, soil basal respiration – BR3) and their relationship to the variability of some physicochemical properties at the surface horizon of Phaeozem were studied. Soil samples were collected at 50 points at regular intervals 10 × 10 m in April and August 2007. Both biomass C and N concentration and FDAH activity showed significantly higher values in April than in August, while DH activity and BR3 range did not significantly differ between both sampling months. To characterise the spatial variability of the properties, spherical, linear or mixed (spherical/linear) models with (BR3, FDAH and MBC in April) or without (DH, FDAH, MBN and MBC in August) the nugget effect, were fitted to the calculated semivariograms. Soil basal respiration and FDA hydrolysis activity (April) were in moderate variability class (the nugget effect between 25 and 75 %), while only MBC in April was in the weak variability class (the nugget effect < 25 %). The ranges of influence calculated for microbiological properties data ranged from 10 to 17 m. Kriged maps displayed irregular distribution of microbial properties in the soil surface and their spatial distribution varied between April and August.
W poziomie powierzchniowym (0-20 cm) czarnej ziemi badano zmienność czasowo-przestrzenną zawartości glebowej biomasy mikrobiologicznej (C i N biomasy mikrobiologicznej - MBC i MBN) oraz jej aktywności (aktywność dehydrogenaz - DH, poziom hydrolizy dioctanu fluoresceiny - FDAH oraz oddychanie glebowe - BR3). W kwietniu i w sierpniu 2007 r. pobrano 50 próbek glebowych z punktów zlokalizowanych w sztywnej siatce kwadratów (10 m 10 m). Wyniki opracowano metodami geostatystycznymi. Zmienność przestrzenną badanych parametrów przedstawiono za pomocą sferycznych lub mieszanych (sferyczno-liniowych) modeli semivariogamów, z efektem samorodka (BR3, FDAH i MBC w kwietniu) lub bez udziału zmienności losowej (DH, FDAH, MBN i MBC w sierpniu). Poziom oddychania gleby oraz aktywność FDAH (kwiecień) znajdowały się w średniej klasie zmienności (wariancja samorodka pomiędzy 25-75 %), jedynie zawartość MBC w kwietniu znajdowała się w niskiej klasie zmienności (wariancja samorodka < 25 %). Zakresy autokorelacji badanych zmiennych wynosiły od 10 do 17 m. Mapy rastrowe wykazały, że wartości badanych zmiennych były nieregularnie rozmieszczone na badanym obszarze. Ponadto, dla wszystkich badanych cech, z wyjątkiem FDAH, uzyskano odmienne rozmieszczenie przestrzenne wyników w obu terminach analiz.
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.
Tematy:
spatio-temporal variability
chlorophyll a
distribution
variability
upwelling
Baltic Sea
Finland Gulf
sea surface temperature
remote sensing
spatial distribution
ecological status
satellite image
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/48503.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł
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.
Tematy:
chromophoric dissolved organic matter
absorption coefficient
sea surface
salinity
chlorophyll a
total suspended matter
spatio-temporal variability
Bengal Bay
continental shelf
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/48552.pdf  Link otwiera się w nowym oknie
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.
Dostawca treści:
Biblioteka Nauki
Artykuł

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