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Wyszukujesz frazę "stable carbon isotope" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Limitation of lignin derivatives as biomarkers of land derived organic matter in the coastal marine sediments
Autorzy:
Pempkowiak, J.
Powiązania:
https://bibliotekanauki.pl/articles/2079190.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
lignin oxidation
biomarker
stable carbon isotope
nonlinear analysis
Gdansk Bay
Southern Baltic Sea
coastal sediment
Opis:
Lignin oxidation products (vanillyl, syringil and cummaryl phenols), and δ13C were measured in a variety of land and marine samples collected in Inner Puck Bay – dominated by marine vascular plants, small river run-off, and shallow bottom, and in Gdańsk Bay – characterized by large river run-off, small marine vascular plants population, and the average depth exceeding euphotic zone. Both study areas are parts of the Gdańsk Basin, Southern Baltic. Typical δ13C values (δ13C = -28‰) and both composition and concentrations of lignin phenols were measured in samples originating from land. Small, yet easily measurable amounts of lignin phenols were found in marine vascular plants biomass (Σ8 = 90 µg/100 mg organic matter). The biomass was characterized by exceptionally high δ13C values (-12‰). No lignin phenols and typical δ13C values (-22‰) were measured in marine phytoplankton biomass. δ13C and both composition and content of lignin phenols in organic matter of surface sediments collected in the study area fall in the range marked by the end members. The proportion of land derived organic matter calculated using lignin phenols, or δ13C in Gdańsk Bay were comparable, while in Puck Bay they differed substantially. It was concluded that a) in areas with substantial bottom coverage with vascular plants the two end members approach, usually employed to establish the contribution of organic matter sources, is insufficient, b) organic matter originating from three sources: riverine, phytoplankton, and vascular plants contribute to sedimentary organic matter in Puck Bay with the respective proportion 30:40:30.
Źródło:
Oceanologia; 2020, 62, 3; 374-386
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elemental and organic carbon proxies for redox conditions of the Oligocene formations in the Ropa Tectonic Window (Outer Carpathians, Poland) : palaeoenvironmental implications
Autorzy:
Wójcik-Tabol, P.
Powiązania:
https://bibliotekanauki.pl/articles/973585.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
organic matter
stable organic carbon isotope
trace metals
anoxia
Grybów Succession
Oligocene
Opis:
The Oligocene Grybów Succession is recognized as a counterpart of the anoxic Menilite Formation. Its comprehensive geochemical investigations are made in the key sections of the Ropa Tectonic Window (the Grybów Unit, Polish Outer Carpathians). The maceral assemblages, dominated by land-plant liptinite, vitrinite and intertinite, correspond to kerogen types II and III. A Tmax vs. HI diagram shows terrestrial kerogen type II with various additions of type III and algal kerogen type I. A variation in δ13Corg. (from –25.21 to –27.38‰) may have resulted from variations in the composition of organic matter (the content of terrestrial vs. marine organic matter), controlled by depositional setting (turbidite vs. hemipelagic). The highest TOC contents are associated with an enhanced influx of land-derived organic matter. The redox-sensitive trace elements positively correlate with TOC and TS contents. Redox conditions varied between oxic and anoxic, as was concluded from TOC-TS, V/(V+Ni) and U/Th. The turbidity currents might have ventilated the bottom waters, especially more efficiently in the proximal zone of turbidite sedimentation. Moreover, oxygenated bottom waters may have also affected the concentration of trace metals, owing to migration of the redox interface downward within the sediments.
Źródło:
Annales Societatis Geologorum Poloniae; 2017, 87, 1; 41-53
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trophic connectivity between intertidal and offshore food webs in Mirs Bay, China
Autorzy:
Ning, J.
Du, F.
Wang, X.
Wang, L.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/47613.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
intertidal zonation
offshore zone
food web
different habitat
trophic interaction
stable isotope
carbon isotope composition
Mirs Bay
China
Źródło:
Oceanologia; 2019, 61, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skład izotopowy dwutlenku węgla w atmosferze Krakowa
Isotopic composition of carbon dioxide in the atmosphere of Kraków
Autorzy:
Jasiek, Alina
Zimnoch, Mirosław
Różański, Kazimierz
Powiązania:
https://bibliotekanauki.pl/articles/578341.pdf
Data publikacji:
2016
Wydawca:
Łódzkie Towarzystwo Naukowe
Tematy:
izotopy trwałe
dwutlenek węgla
izotopowy bilans masy
stable isotopes
carbon dioxide
isotope mass balance
Opis:
Izotopy trwałe stanowią doskonałe narzędzie do analizy źródeł pochodzenia gazów cieplarnianych. Znając specyficzne sygnatury izotopowe poszczególnych źródeł dwutlenku węgla można określić pochodzenie CO2 nagromadzonego w miejskiej atmosferze. Kwasi-ciągłe pomiary stężenia i składu izotopowego węgla w atmosferycznym CO2 prowadzone w 2013 roku w Krakowie pozwoliły na dokonanie analizy ich zmienności sezonowej oraz synoptycznej. Źródłem obserwowanych zimą zwiększonych stężeń CO2 w atmosferze Krakowa było spalanie, w głównej mierze gazu ziemnego w celach grzewczych. Latem zaobserwowano wpływ suszy na stężenie CO2 w miejskiej atmosferze – z powodu obumierania lokalnej biosfery zmalała jej wydajność fotosyntetyczna, prowadząc do wyższych niż normalnie stężeń tego gazu w miesią - cach letnich. Przeprowadzono również dyskusję przyczyn krótkoterminowych wzrostów stężenia dwutlenku węgla, wykorzystując pomiary jego składu izotopowego oraz analizy trajektorii wstecznych mas powietrza. Zaprezentowane dwa przypadki ilustrują sytuacje, w których za chwilowy wzrost stężenia CO2 odpowiadają źródła przemysłowe oraz komunikacyjne.
Stable isotopes constitute a powerful tool to study the sources of greenhouse gases, especially CO2. Carbon dioxide derived from the burning of fossil fuels has a distinct 13C isotopic composition depending on the type of fuel. Therefore, one can attribute contributions of different emission sources to the total CO2 load in the urban atmosphere. Quasi-continuous measurements of the mixing ratio of atmospheric CO2 and its 13C signature were performed in Krakow in 2013 to analyze its seasonal and synoptic variability. High CO2 mixing ratios were observed in winter due to intensified burning of fossil fuels for heating purposes (mostly methane). During the summer of 2013, a slight increase in atmospheric CO2 was observed following a drought event and a subsequent suppression of the photosynthetic activity of the local biosphere. A high temporal resolution of the measurements allowed to analyze short-term increases of the measured CO2 mixing ratios. Two such events are presented and discussed. Isotopic mass balance combined with air backward trajectory analysis allowed to attribute local traffic and industry as potential sources of these events.
Źródło:
Acta Geographica Lodziensia; 2016, 104; 113-122
0065-1249
Pojawia się w:
Acta Geographica Lodziensia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tracing the signature of various frontal systems in stable isotopes (oxygen and carbon) of the planktonic foraminiferal species Globigerina bulloides in the Southern Ocean (Indian Sector)
Autorzy:
Khare, N.
Chaturvedi, S.K.
Powiązania:
https://bibliotekanauki.pl/articles/48922.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Foraminifera
Globigerina bulloides
stable isotope
frontal system
oxygen
carbon
foraminiferal species
water mass
Southern Ocean
Opis:
Twenty-five surficial sediment samples, collected on board ORV Sagar Kanya during her 199th and 200th cruises along a north-south transect between latitudes 9.69◦N and 55.01◦S, and longitudes 80◦E and 40◦ E were studied for isotopic variations (values of δ18O and δ13C) of the indicator planktonic species Globigerina bulloides. The results indicate that from latitudes 9.69◦N to 15◦ S both these isotopes (δ18O and δ13C) fluctuated significantly. Between latitudes from around 15◦S to 30–35◦S δ18O values steadily increased, whereas δ13C showed a decreasing trend. However, to the south of latitudes 30–35◦S, both isotope values showed a similar response with a gradual increase up to latitude 50◦S, beyond which δ18O continued to increase while δ13C declined. The characteristic patterns of the values of both isotopes indicates that the signatures of different water masses are associated with various frontal systems and/or water masses across the transect. The signature of the Polar Front at around latitude 50◦S shows the specific response of the isotopic values (δ18O and δ13C) of G. bulloides. Such a response beyond 50◦S latitude is ascribable to the general decrease in the ambient temperature, resulting in a continuous increase in δ18O values, while δ13C values decrease as a result of reduced photosynthesis in regions approaching higher latitudes owing to low light penetration. To further corroborate our results, those of many such transects from geographically distinct regions need to be studied for isotopic variations in the calcareous shells of planktonic foraminiferal species. The results have the potential to be used as a proxy to assess the movement of frontal systems in southern high latitude regions.
Źródło:
Oceanologia; 2012, 54, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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