scholarly journals Borexino experiment detects neutrinos from the Sun’s carbon-nitrogen-oxygen cycle

Physics Today ◽  
2021 ◽  
Vol 74 (2) ◽  
pp. 12-14
Author(s):  
R. Mark Wilson
Keyword(s):  
Oxygen Cycle

PROBING THE EARTH'S DEEP OXYGEN CYCLE WITH VANADIUM: THE TEMPERATURE DEPENDENCE OF PARTITIONING

2018 ◽  
Author(s):  
Rilla McKeegan ◽  
◽  
Megan Holycross ◽  
Elizabeth Cottrell
Keyword(s):  
Temperature Dependence ◽  
Oxygen Cycle

A nephelinitic component with unusual δ56Fe in Cenozoic basalts from eastern China and its implications for deep oxygen cycle

2019 ◽  
Vol 512 ◽  
pp. 175-183 ◽  
Author(s):  
Yongsheng He ◽  
Xunan Meng ◽  
Shan Ke ◽  
Hongjie Wu ◽  
Chuanwei Zhu ◽  
...  
Keyword(s):  
Eastern China ◽  
Oxygen Cycle

scholarly journals An Overview of Surface Water Quality Influenced by Suspended Solid Content in the Sayung Waters, Demak, Indonesia

Jurnal Segara ◽  
2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Ulung Jantama Wisha ◽  
Koko Ondara ◽  
Gunardi Kusumah
Keyword(s):  
High Tide ◽  
Surface Water Quality ◽  
Sampling Technique ◽  
Suspended Solid ◽  
Solid Content ◽  
Current Speed ◽  
Oxygen Cycle ◽  
Chemical Content ◽  
Fertile Area

Abrasion which is occurred in the Sayung coast is triggered by a big role of climate change as well as the sea level rise and land subsidence. Resulting degradation ultimately affects changes in existing environmental conditions. This study has aim to determine the existing water based on biological and chemical content which is affected by increasing suspended solid content in the Sayung waters. Purposive sampling technique was applied, and data is analyzed both statistically and spatially. Suspended solid value has ranged 23,1-199,6 mg/L. Distribution of suspended solid was only simulated during low tide towards high tide phase with current speed has ranged 0-0.41 m/s. We found that dissolved oxygen value is quite high in several observation stations which indicates the fertile area with low pollution and blooming tendency. In the station which is dominated by a high suspended solid and turbidity found that the chlorophyll-a decreases. The increased rate of suspended solid is directly enhancing the turbidity and indirectly declines the photosynthesis activity and inhibits the oxygen cycle. Resulting in the primary productivity reduction in the Sayung waters

scholarly journals The impact of composition choices on solar evolution: age, helio- and asteroseismology, and neutrinos

2020 ◽  
Vol 498 (2) ◽  
pp. 1992-2000
Author(s):  
Diogo Capelo ◽  
Ilídio Lopes
Keyword(s):  
The Sun ◽  
Fundamental Parameters ◽  
Element Abundances ◽  
Solar Evolution ◽  
Oxygen Cycle ◽  
Potential Impact ◽  
Red Giant ◽  
Neutrino Fluxes ◽  
Neutrino Experiments ◽  
The Impact

ABSTRACT The Sun is the most studied and well-known star, and as such, solar fundamental parameters are often used to bridge gaps in the knowledge of other stars, when these are required for modelling. However, the two most powerful and precise independent methodologies currently available to infer the internal solar structure are in disagreement. We aim to show the potential impact of composition choices in the overall evolution of a star, using the Sun as example. To this effect, we create two Standard Solar Models and a comparison model using different combinations of metallicity and relative element abundances and compare evolutionary, helioseismic, and neutrino-related properties for each. We report differences in age for models calibrated to the same point on the HR diagram, in red giant branch, of more than 1 Gyr, and found that the current precision level of asteroseismic measurements is enough to differentiate these models, which would exhibit differences in period spacing of 1.30–2.58 per cent. Additionally, we show that the measurement of neutrino fluxes from the carbon–nitrogen–oxygen cycle with a precision of around 17 per cent, which could be achieved by the next generation of solar neutrino experiments, could help resolve the stellar abundance problem.

scholarly journals Planetary fertility during the past 400 ka based on the triple isotope composition of O<sub>2</sub> in trapped gases from the Vostok ice core

2012 ◽  
Vol 8 (5) ◽  
pp. 1509-1526 ◽  
Author(s):  
T. Blunier ◽  
M. L. Bender ◽  
B. Barnett ◽  
J. C. von Fischer
Keyword(s):  
Isotope Exchange ◽  
Isotope Composition ◽  
Atmospheric Oxygen ◽  
Ice Core ◽  
Fractionation Process ◽  
Factors Affecting ◽  
Mass Independent Fractionation ◽  
Oxygen Cycle ◽  
Steady State Model ◽  
O2 Production

Abstract. The productivity of the biosphere leaves its imprint on the isotopic composition of atmospheric oxygen. Ultimately, atmospheric oxygen, through photosynthesis, originates from seawater. Fractionations during the passage from seawater to atmospheric O2 and during respiration affect δ17O approximately half as much as δ18O. An "anomalous" (also termed mass independent) fractionation process changes δ17O about 1.7 times as much as δ18O during isotope exchange between O2 and CO2 in the stratosphere. The relative rates of biological O2 production and stratospheric processing determine the relationship between δ17O and δ18O of O2 in the atmosphere. Variations of this relationship thus allow us to estimate changes in the rate of O2 production by photosynthesis versus the rate of O2–CO2 isotope exchange in the stratosphere. However, the analysis of the 17O anomaly is complicated because each hydrological and biological process fractionates δ17O and δ18O in slightly different proportions. In this study we present O2 isotope data covering the last 400 ka (thousand years) from the Vostok ice core. We reconstruct oxygen productivities from the triple isotope composition of atmospheric oxygen with a box model. Our steady state model for the oxygen cycle takes into account fractionation during photosynthesis and respiration by the land and ocean biosphere, fractionation during the hydrologic cycle, and fractionation when oxygen passes through the stratosphere. We consider changes of fractionation factors linked to climate variations, taking into account the span of estimates of the main factors affecting our calculations. We find that ocean oxygen productivity was within 20% of the modern value throughout the last 400 ka. Given the presumed reduction in terrestrial oxygen productivity, the total oxygen production during glacials was likely reduced.

The oxygen budget of two closed, dimictic lakes in the vicinity of Bytów (West Pomeranian Lake District, northern Poland)

2010 ◽  
Vol 39 (2) ◽  
Author(s):  
Zbigniew Witek ◽  
Anna Jarosiewicz
Keyword(s):  
Oxygen Release ◽  
Key Factors ◽  
Lake District ◽  
Trophic Conditions ◽  
Phytoplankton Primary Production ◽  
Stratified Lakes ◽  
Oxygen Budget ◽  
Northern Poland ◽  
Oxygen Cycle ◽  
Turn Over

The oxygen budget of two closed, dimictic lakes in the vicinity of Bytów (West Pomeranian Lake District, northern Poland)The aim of this work was to identify key factors governing the oxygen fluxes in two thermally stratified lakes of different morphology. Oxygen and temperature profiles in lakes Jeleń and Mały Borek, as well as phytoplankton primary production in Mały Borek (oxygen-method) were measured in monthly intervals, except for periods of ice cover. Rates of oxygen release due to photosynthesis, consumption in the water column, loss to atmosphere, depletion in the hypolimnion, and restoration during periods of turn-over were roughly estimated. It was discovered that trophic conditions and morphometry may substantially influence not only the intensity, but also the timing, of particular events in the oxygen cycle of the lakes.

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