scholarly journals A potential suite of climate markers of long-chain n-alkanes and alkenones preserved in the top sediments from the Pacific sector of the Southern Ocean

2021 ◽  
Author(s):  
Xin Chen ◽  
Xiaodong Liu ◽  
Da-Cheng Lin ◽  
Jianjun Wang ◽  
Liqi Chen ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Organic Compounds ◽  
Higher Plant ◽  
Δ13c Values ◽  
New Information ◽  
The Pacific ◽  
Study Results ◽  
Chemoautotrophic Bacteria ◽  
Plant Waxes ◽  
Long Chain

Abstract Investigating organic compounds in marine sediments can potentially unlock a wealth of new information in these climate archives. Here we present pilot study results of organic geochemical features of long-chain n-alkanes and alkenones and individual carbon isotope ratios of long-chain n-alkanes from a newly collected, approximately 8-meter long, located in the far reaches of the Pacific sector of the Southern Ocean. We analyzed a suite of organic compounds in the core. The results show abundant long-chain n-alkanes (C29-C35) with predominant odd-over-even carbon preference, suggesting an origin of terrestrial higher plant waxes via long-range transport of dust, possibly from Australia and New Zealand. The δ13C values of the C31 n-alkane range from -29.4 to -24.8‰, in which the higher δ13C values suggest more contributions from C4 plant waxes. In the analysis, we found that the mid-chain n-alkanes (C23-C25) have a small odd-over-even carbon preference, indicating that they were derived from marine non-diatom pelagic phytoplankton and microalgae and terrestrial sources. Furthermore, the C26 and C28 with lower δ13C values (~ -34‰) indicate an origin from marine chemoautotrophic bacteria. We found that the abundances of tetra-unsaturated alkenones (C37:4) in this Southern Ocean sediment core ranges from 11-37%, perhaps a marker of low sea surface temperature (SST). The results of this study strongly indicate that the δ13C values of long-chain n-alkanes and index are potentially useful to reconstruct the detailed history of C3/C4 plants and SST change in the higher latitudes of the Southern Ocean.

scholarly journals A potential suite of climate markers of long-chain n-alkanes and alkenones preserved in the top sediments from the Pacific sector of the Southern Ocean

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xin Chen ◽  
Xiaodong Liu ◽  
Da-Cheng Lin ◽  
Jianjun Wang ◽  
Liqi Chen ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Organic Compounds ◽  
Higher Plant ◽  
New Information ◽  
The Pacific ◽  
Study Results ◽  
History Of ◽  
Chemoautotrophic Bacteria ◽  
Plant Waxes ◽  
Long Chain

AbstractInvestigating organic compounds in marine sediments can potentially unlock a wealth of new information in these climate archives. Here, we present pilot study results of organic geochemical features of long-chain n-alkanes and alkenones and individual carbon isotope ratios of long-chain n-alkanes from a newly collected, approximately 8 m long, located in the far reaches of the Pacific sector of the Southern Ocean. We analyzed a suite of organic compounds in the core. The results show abundant long-chain n-alkanes (C29–C35) with predominant odd-over-even carbon preference, suggesting an origin of terrestrial higher plant waxes via long-range transport of dust, possibly from Australia and New Zealand. The δ13C values of the C31n-alkane range from −29.4 to −24.8‰, in which the higher δ13C values suggest more contributions from C4 plant waxes. In the analysis, we found that the mid-chain n-alkanes (C23–C25) have a small odd-over-even carbon preference, indicating that they were derived from marine non-diatom pelagic phytoplankton and microalgae and terrestrial sources. Furthermore, the C26 and C28 with lower δ13C values (~−34‰) indicate an origin from marine chemoautotrophic bacteria. We found that the abundances of tetra-unsaturated alkenones (C37:4) in this Southern Ocean sediment core ranges from 11 to 37%, perhaps a marker of low sea surface temperature (SST). The results of this study strongly indicate that the δ13C values of long-chain n-alkanes and $$ {U}_{37}^{\mathrm{k}} $$ U 37 k index are potentially useful to reconstruct the detailed history of C3/C4 plants and SST change in the higher latitudes of the Southern Ocean.

scholarly journals A Potential Suite of Climate Markers of Long-Chain n-Alkanes and Alkenones Preserved in the top Sediments from the Pacific Sector of the Southern Ocean

2020 ◽  
Author(s):  
Xin Chen ◽  
Xiaodong Liu ◽  
Da-Cheng Lin ◽  
Jianjun Wang ◽  
Liqi Chen ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Organic Compounds ◽  
Sediment Core ◽  
Higher Plant ◽  
New Information ◽  
The Pacific ◽  
Study Results ◽  
History Of ◽  
Chemoautotrophic Bacteria ◽  
Long Chain

Abstract Investigation of organic compounds in marine sediments can potentially unlock a wealth of new information in these overlooked climate archives. Here we present pilot study results of organic geochemical features of long-chain n-alkanes and alkenones and individual carbon isotope ratios of long-chain n-alkanes from a newly collected, approximately 8-meter long, Pleistocene age sediment core, located in the far reaches of the Pacific sector of the Southern Ocean. We initially analyzed a suite of organic compounds in the core, and the results show abundant long-chain n-alkanes (C29-C35) with predominant odd-over-even carbon preference, which suggests an origin of terrestrial higher plant waxes via long range transport of dust, possibly from Australia and New Zealand. The δ13C values of the C31 n-alkane range from -29.4 to -24.8‰, in which the higher δ13C values suggest more contributions from C4 plants waxes. In the analysis, we found that the mid-chain n-alkanes (C23-C25) have small odd-over-even carbon preference, suggesting that they were derived from marine non-diatom pelagic phytoplankton and microalgae, and terrestrial sources. Furthermore, the C26 and C28 with lower δ13C values (~ -34‰) indicate an origin from marine chemoautotrophic bacteria. We found that the abundances of tetra-unsaturated alkenones (C37:4) in this Southern Ocean sediment core ranges from 11-37%, perhaps a marker of low sea surface temperature (SST). The results of this study strongly indicate that the δ13C values of long-chain n-alkanes and index are potentially useful to reconstruct detailed history of C3/C4 plants and SST change in the higher latitudes of the Southern Ocean.

scholarly journals Lipid abundance and composition of a humic Oxisol as a function of land use

2011 ◽  
Vol 68 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Cristiane Pereira de Assis ◽  
Francisco Javier González-Vila ◽  
Ivo Jucksch ◽  
Jose Antonio González-Pérez ◽  
Júlio César Lima Neves ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Lipid Composition ◽  
Gas Chromatography Mass Spectrometry ◽  
Native Forest ◽  
Higher Plant ◽  
Alkanoic Acids ◽  
Plant Waxes ◽  
Long Chain

Soil organic matter of a humic Oxisol has been characterized by analyzing litter and soil lipid composition under vegetal covers (coffee, pasture and fragment of native forest). Soil and litter samples were collected from each site at two depths (0-10 and 60-100 cm). Lipid composition was determined by gas chromatography-mass spectrometry (CG-MS). In the solvent extracts of the soil lipids, even-numbered n-alkanoic acids in the range of C16-C32 indicate a soil organic matter input from higher plant waxes. The major compound classes in both the soil and the litter included saturated n-alkanoic acids, with average values in the total spectrum of 58 and 53%, respectively Clear differences in lipid composition were found between the topsoil and subsurface. Long chain alkylic compounds (alkanoic acids and alkanes) accumulated preferably at depths of 60-100 cm. On the surface, the soil from natural vegetation had a total lipid value higher than those cultivated soils, and showed a predominance of unsaturated alkanoic acids at 60-100 cm. Preservation of alkylic moieties with depth was observed under forest and pasture, indicating that these systems of land use are prone to lipid accumulation. Lipids, especially the long-chain (> C20) ones, may be important with regard to C stabilization and humification processes in subsoil of humic Oxisols, highlighting the importance of lipids compounds in the bulk structure of organic matter these soils.

scholarly journals Energy exchange in early spring over sea ice in the Pacific sector of the Southern Ocean

1999 ◽  
Vol 104 (D4) ◽  
pp. 3925-3935 ◽  
Author(s):  
Adrian Hauser ◽  
Gerd Wendler ◽  
Ute Adolphs ◽  
Martin O. Jeffries
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Energy Exchange ◽  
Early Spring ◽  
The Pacific

Eddy properties in the Pacific sector of the Southern Ocean from satellite altimetry data

2016 ◽  
Vol 35 (11) ◽  
pp. 28-34 ◽  
Author(s):  
Yongliang Duan ◽  
Hongwei Liu ◽  
Weidong Yu ◽  
Yijun Hou
Keyword(s):  
Southern Ocean ◽  
Satellite Altimetry ◽  
Altimetry Data ◽  
The Pacific ◽  
Satellite Altimetry Data

scholarly journals Subantarctic Mode Water Formation, Destruction, and Export in the Eddy-Permitting Southern Ocean State Estimate

2013 ◽  
Vol 43 (7) ◽  
pp. 1485-1511 ◽  
Author(s):  
Ivana Cerovečki ◽  
Lynne D. Talley ◽  
Matthew R. Mazloff ◽  
Guillaume Maze
Keyword(s):  
Southern Ocean ◽  
Buoyancy Flux ◽  
Differential Heat ◽  
Diapycnal Mixing ◽  
Mode Water ◽  
State Estimate ◽  
Surface Formation ◽  
Subantarctic Mode Water ◽  
The Pacific ◽  
The Difference

Abstract Subantarctic Mode Water (SAMW) is examined using the data-assimilating, eddy-permitting Southern Ocean State Estimate, for 2005 and 2006. Surface formation due to air–sea buoyancy flux is estimated using Walin analysis, and diapycnal mixing is diagnosed as the difference between surface formation and transport across 30°S, accounting for volume change with time. Water in the density range 26.5 < σθ < 27.1 kg m−3 that includes SAMW is exported northward in all three ocean sectors, with a net transport of (18.2, 17.1) Sv (1 Sv ≡ 106 m3 s−1; for years 2005, 2006); air–sea buoyancy fluxes form (13.2, 6.8) Sv, diapycnal mixing removes (−14.5, −12.6) Sv, and there is a volume loss of (−19.3, −22.9) Sv mostly occurring in the strongest SAMW formation locations. The most vigorous SAMW formation is in the Indian Ocean by air–sea buoyancy flux (9.4, 10.9) Sv, where it is partially destroyed by diapycnal mixing (−6.6, −3.1) Sv. There is strong export to the Pacific, where SAMW is destroyed both by air–sea buoyancy flux (−1.1, −4.6) Sv and diapycnal mixing (−5.6, −8.4) Sv. In the South Atlantic, SAMW is formed by air–sea buoyancy flux (5.0, 0.5) Sv and is destroyed by diapycnal mixing (−2.3, −1.1) Sv. Peaks in air–sea flux formation occur at the Southeast Indian and Southeast Pacific SAMWs (SEISAMWs, SEPSAMWs) densities. Formation over the broad SAMW circumpolar outcrop windows is largely from denser water, driven by differential freshwater gain, augmented or decreased by heating or cooling. In the SEISAMW and SEPSAMW source regions, however, formation is from lighter water, driven by differential heat loss.

Role Strain, Coping, and Marital Satisfaction of Stepparents

1992 ◽  
Vol 73 (2) ◽  
pp. 79-92 ◽  
Author(s):  
Doni Whitsett ◽  
Helen Land
Keyword(s):  
Marital Satisfaction ◽  
Inverse Relationship ◽  
Role Strain ◽  
Self Esteem ◽  
Coping Resources ◽  
Cross Sectional ◽  
New Information ◽  
Study Results ◽  
And Coping ◽  
The Relationship

The relationship among role strain, coping, and marital satisfaction is examined in a cross-sectional sample of 73 stepparents. New information is discussed pertaining to differential types of role strain identified in stepparent groups. The association between types of role strain and differential types of coping strategies and coping resources is analyzed. Results document the association between coping resources of self-esteem and self-efficacy and certain dimensions of role strain. An inverse relationship between role strain and marital satisfaction is noted. Based on study results, the authors identify vulnerable subgroups and suggest implications for practice with stepfamilies.

scholarly journals Identification of animal fats via compound specific δ13C values of individual fatty acids: assessments of results for reference fats and lipid extracts of archaeological pottery vessels

2002 ◽  
Vol 29 ◽  
pp. 73-96 ◽  
Author(s):  
Richard P. Evershed ◽  
Stephanie N. Dudd ◽  
Mark S. Copley ◽  
Anna Mutherjee
Keyword(s):  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
New Approach ◽  
Δ13c Values ◽  
Animal Fats ◽  
Dietary Preferences ◽  
Archaeological Pottery ◽  
New Information ◽  
Molecular Information ◽  
Infor Mation

The possibility of obtaining molecular information from lipid residues associated with archaeological pottery has dramatically increased the potential for deriving new information on the use of ancient vessels and the commodities processed therein. Motivated by the high proportion of the archaeological potsherds that have been shown to contain animal fats, a new approach invol- ving compound specific stable isotope analysis of remnant fats has been developed to retrieve infor- mation which will allow new insights into animal exploitation, dietary preferences and vessel use amongst prehistoric peoples. The new approach uses the δ13C values of the major saturated fatty acid (C16:0 and C18:0) determined by gas chromatography-combustion-isotope ratio mass spectrometry (GC–C–IRMS) to characterise the origins of animal fat recovered from archaeological pottery.

Copepod Communities in the Pacific Sector of the Southern Ocean in Early Summer

2000 ◽  
pp. 291-307 ◽  
Author(s):  
T. Zunini Sertorio ◽  
P. Licandro ◽  
C. Ossola ◽  
A. Artegiani
Keyword(s):  
Southern Ocean ◽  
Early Summer ◽  
The Pacific

Blood concentrations of volatile organic compounds in a nonoccupationally exposed US population and in groups with suspected exposure

1994 ◽  
Vol 40 (7) ◽  
pp. 1401-1404 ◽  
Author(s):  
D L Ashley ◽  
M A Bonin ◽  
F L Cardinali ◽  
J M McCraw ◽  
J V Wooten
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Reference Range ◽  
Industrialized Countries ◽  
Blood Concentrations ◽  
Health And Nutrition ◽  
Low Concentrations ◽  
Study Results ◽  
The Us ◽  
Volatile Organic

Abstract Exposure to certain volatile organic compounds (VOCs) commonly occurs in industrialized countries. We developed a method for measuring 32 VOCs in 10 mL of whole blood at low concentration. We used this method to determine the internal dose of these compounds in 600 or more people in the US who participated in the Third National Health and Nutrition Examination Survey. From our study results, we established a reference range for these VOCs in the general population of the US. We found detectable concentrations of 1,1,1-trichloroethane, 1,4-dichlorobenzene, 2-butanone, acetone, benzene, chloroform, ethylbenzene, m,p-xylene, styrene, tetrachloroethane, and toluene in most of the blood samples of nonoccupationally exposed persons. The accuracy of VOC evaluations depends on the ability of investigators to make sensitive and reproducible measurements of low concentrations of VOCs and to eliminate all sources of interference and contamination.

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