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Wyszukujesz frazę "temporal distribution" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Spatial and temporal distribution of heavy metals in coastal core sediments from the Red Sea, Saudi Arabia
Autorzy:
Al-Mur, B.A.
Quicksall, A.N.
Al-Ansari, A.M.A.
Powiązania:
https://bibliotekanauki.pl/articles/48599.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Red Sea
Saudi Arabia
heavy metal
spatial distribution
temporal distribution
pollution
coastal sediment
sediment core
Opis:
Jeddah is the most industrialized city on the west coast of Saudi Arabia and is under increasing influence of human activities. Heavy metals data were obtained from four near-coast Red Sea sediment cores in close proximity to Jeddah. Chromium, manganese, iron, copper, zinc, and lead were analyzed from depth-resolved sections of each core via heavy acid digestion and inductively coupled plasma-mass spectrometry (ICP-MS). The average concentrations of all four sites were 245.96 mg kg1, 478.45 mg kg1, 8506.13 mg kg1, 251.82 mg kg1, 623.09 mg kg1, and 362.75 mg kg1, respectively. The depth-resolved results showed that highest concentrations of Mn, Cu, and Pb were found in the top 15 cm of the core profile distributions compared to other depth sub-samples. Heavy metal concentrations in core sediments are increased near central Jeddah and have become higher in recent years. The results of enrichment factor calculations indicate little anthropogenic supply of Mn and Cr while Pb, Zn, and Cu show strong anthropogenic input. The Pollution Load Index was higher in the two sites closer to central Jeddah where power and desalination plants and wastewater release are known. This indicates that the area has suffered from heavy metal pollution compared to other non-industrialized sites in the Red Sea. Heavy metal contaminations due to anthropogenic activity should be taken into account to protect the Red Sea during future growth. The results of this work should be considered as a baseline for heavy metals monitoring in the sediments of the Red Sea coast near Jeddah, Saudi Arabia.
Źródło:
Oceanologia; 2017, 59, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent sea surface temperature trends and future scenarios for the Mediterranean Sea
Autorzy:
Shaltout, M.
Omstedt, A.
Powiązania:
https://bibliotekanauki.pl/articles/49032.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Mediterranean Sea
sea surface temperature
temporal distribution
spatial distribution
climate change
heat exchange
cloud cover
variation coefficient
Źródło:
Oceanologia; 2014, 56, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reproductive cycle and the related spatial and temporal distribution of the ninespine stickleback (Pungitius pungitius L.) in Puck Bay
Autorzy:
Sokolowska, E.
Skora, K.E.
Powiązania:
https://bibliotekanauki.pl/articles/48433.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Pungitius pungitius
ninespine stickleback
reproductive cycle
temporal distribution
Puck Bay
breeding period
spawning
spatial distribution
maturity stage
Opis:
The cycle of gonad development and related changes in the length structure and spatial-temporal distribution of ninespine sticklebacks (Pungitius pungitius L.) in Puck Bay were studied. Observations were carried out in the shallow shore zones, as well as in the deeper epipelagic zone of the Bay. Ninespine sticklebacks reproduce in the brackish environment of Puck Bay, breeding in its warmer, inshore zones. Reproduction takes place in the spring and summer months, from April to July. One female spawns several clutches of eggs during one breeding season. The average length of ninespine sticklebacks in Puck Bay was about 40 mm, and the sex ratio in the population was close to 1:1. However, both length structure and sex ratio were subject to local and periodic variations, resulting from possible breeding-related territorial divisions. Higher gonadosomatic indices in females in early spring represented the transition of fish to the advanced vitelligenous phase. The lowest GSI of males during the breeding season indicated the termination of spermatogenesis. The completion of spawning in August started a new process of gonad restoration to prepare the fish for the next breeding season.
Źródło:
Oceanologia; 2002, 44, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Short-term variation of zooplankton community in Cintra Bay (Northwest Africa)
Autorzy:
Berraho, A.
Abdelouahab, H.
Baibai, T.
Charib, S.
Larissi, J.
Agouzouk, A.
Makaoui, A.
Powiązania:
https://bibliotekanauki.pl/articles/49175.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
zooplankton
short-term variability
copepod
diversity index
environment parameter
spatial-temporal distribution
Cintra Bay
Africa
Źródło:
Oceanologia; 2019, 61, 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:
Temporal changes in the concentrations of zinc and cadmium in the sedimentary strata of Nozha Hydrodrome, Alexandria, Egypt
Autorzy:
Rifaat, A.E.
Ahdy, H.H.H.
Powiązania:
https://bibliotekanauki.pl/articles/48576.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
agricultural development
Alexandria
aquatic environment
cadmium concentration
Egypt
heavy metal
industrial development
Nozha Hydrodrome
sediment
sewage effluent
temporal change
urban development
vertical distribution
zinc concentration
Opis:
This study is concerned with the temporal changes in the levels of zinc and cadmium in the sediments of Nozha Hydrodrome during the past 100 years. Seven sediment core samples, covering the study area, were collected from the bottom of the Hydrodrome. A five-step sequential extraction technique was applied to determine the solid phase concentrations of zinc and cadmium. Zinc gives an idea of the quantities of sewage effluents, while cadmium provides an indication of the amounts of agricultural discharges. The vertical distribution curves show that the average total concentrations of zinc in the sediments increased at a rate of 2.5 μg g−1 y−1 from 1900 to 1950 and at 1.5 μg g−1 y−1 from 1950 to 1990. Since 1990 the zinc concentration in Nozha Hydrodrome sediments has been decreasing at 1.5 μg g−1 y−1. The average total cadmium concentration exhibits a different vertical distribution pattern: it increased at a rate of 0.42 μg g−1 y−1 from 1900 to 1950, after which it became constant from 1950 to 1970. Since 1970 it has been increasing at 0.53 μg g−1 y−1. The ongoing increase in cadmium concentrations in the sediments is due to the increase in agricultural discharges into the Hydrodrome, especially as significant amounts of phosphate fertilizers are used to nourish the soil around the Hydrodrome. The rise in cadmium concentrations since 1900 has been accompanied by a similar increase in zinc concentrations with time resulting from the discharge of untreated sewage into the Hydrodrome. In 1990 a sewerage system and sewage treatment plant came into operation, as a result of which discharges of domestic effluent into the Hydrodrome ceased. Since then the amount of zinc in sediments has been decreasing steadily.
Źródło:
Oceanologia; 2011, 53, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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