Back to Search
Start Over
Highly branched isoprenoids for Southern Ocean sea ice reconstructions: a pilot study from the Western Antarctic Peninsula
- Source :
- Biogeosciences, Vol 16, Pp 2961-2981 (2019), EPIC3Biogeosciences, COPERNICUS GESELLSCHAFT MBH, 16(15), pp. 2961-2981, ISSN: 1726-4170
- Publication Year :
- 2019
-
Abstract
- Organic geochemical and micropaleontological analyses of surface sediments collected in the southern Drake Passage and the Bransfield Strait, Western Antarctic Peninsula, enable a proxy-based reconstruction of recent sea ice conditions in this climate-sensitive area. We study the distribution of the sea ice biomarker IPSO25, and biomarkers of open marine environments such as more unsaturated highly branched isoprenoid alkenes and phytosterols. Comparison of the sedimentary distribution of these biomarker lipids with sea ice data obtained from satellite observations and diatom-based sea ice estimates provide for an evaluation of the suitability of these biomarkers to reflect recent sea surface conditions. The distribution of IPSO25 supports earlier suggestions that the source diatom seems to be common in near-coastal environments characterized by annually recurring sea ice cover, while the distribution of the other biomarkers is highly variable. Offsets between sea ice estimates deduced from the abundance of biomarkers and satellite-based sea ice data are attributed to the different time intervals recorded within the sediments and the instrumental records from the study area, which experienced rapid environmental changes during the past 100 years. To distinguish areas characterized by permanently ice-free conditions, seasonal sea ice cover and extended sea ice cover, we apply the concept of the PIP25 index from the Arctic Ocean to our data and introduce the term PIPSO25 as a potential sea ice proxy. While the trends in PIPSO25 are generally consistent with satellite sea ice data and winter sea ice concentrations in the study area estimated by diatom transfer functions, more studies on the environmental significance of IPSO25 as a Southern Ocean sea ice proxy are needed before this biomarker can be applied for semi-quantitative sea ice reconstructions.
- Subjects :
- 010504 meteorology & atmospheric sciences
lcsh:Life
010502 geochemistry & geophysics
01 natural sciences
Proxy (climate)
Surface conditions
Peninsula
lcsh:QH540-549.5
Sea ice
14. Life underwater
Ecology, Evolution, Behavior and Systematics
0105 earth and related environmental sciences
Earth-Surface Processes
geography
geography.geographical_feature_category
biology
lcsh:QE1-996.5
biology.organism_classification
The arctic
lcsh:Geology
Ocean sea
lcsh:QH501-531
Oceanography
Diatom
13. Climate action
Sedimentary rock
lcsh:Ecology
Geology
Subjects
Details
- Language :
- English
- ISSN :
- 17264189
- Database :
- OpenAIRE
- Journal :
- Biogeosciences, Vol 16, Pp 2961-2981 (2019), EPIC3Biogeosciences, COPERNICUS GESELLSCHAFT MBH, 16(15), pp. 2961-2981, ISSN: 1726-4170
- Accession number :
- edsair.doi.dedup.....d27fa53249d6c914e8be9b0a151fe47b