Reconstructing sea surface temperature in the South Pacific using organic proxies
Sea surface temperature (SST), at the interface between the atmosphere and the ocean, is an important element in the global climate system. Accurate estimates of past SSTs are indispensable for studying global climate and for validating the numerical models used for projections of future climate. SS...
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Universität Bremen
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ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/429 2023-05-15T18:25:59+02:00 Reconstructing sea surface temperature in the South Pacific using organic proxies Rekonstruktion von Meeresoberflächentemperaturen im Südpazifik mittels organischer Proxies Ho, Sze Ling Tiedemann, Ralf Mollenhauer, Gesine 2012-10-30 application/pdf https://media.suub.uni-bremen.de/handle/elib/429 https://nbn-resolving.org/urn:nbn:de:gbv:46-00102943-16 eng eng Universität Bremen FB5 Geowissenschaften https://media.suub.uni-bremen.de/handle/elib/429 urn:nbn:de:gbv:46-00102943-16 info:eu-repo/semantics/openAccess Bitte wählen Sie eine Lizenz aus: (Unsere Empfehlung: CC-BY) CC-BY sea surface temperature alkenone GDGT UK37 TEX86 Southeast Pacific 550 550 Earth sciences and geology ddc:550 Dissertation doctoralThesis 2012 ftsubbremen 2022-11-09T07:09:22Z Sea surface temperature (SST), at the interface between the atmosphere and the ocean, is an important element in the global climate system. Accurate estimates of past SSTs are indispensable for studying global climate and for validating the numerical models used for projections of future climate. SSTs prior to the instrumentation era could be reconstructed using climatically sensitive biomarkers such as alkenones and glycerol dialkyl glycerol tetraethers (GDGTs). Herein I use marine sediments, both core-tops and long piston cores, to further examine the applicability of organic SST proxies derived from the aforementioned biomarkers, with an emphasis on the relatively under-studied subantarctic Southeast Pacific. The appraisal of these proxies is based on the correlation of the core-top proxy index values with present-day climatological SST, and the comparison of the SST records inferred from these proxies with other regional SST records. The alkenone index (UK37 and UK 37) values in the South Pacific core-tops display linear relationships with climatological World Ocean Atlas 2009 (WOA09) SST at low temperatures (1 -12°C), with equally high r2 values (>0.93). These results suggest that both alkenone indices are highly correlated to SST even at high latitudes, rendering them appropriate for reconstructing SST in the subantarctic Pacific. However, these indices yield different Pleistocene SST patterns for study sites in the subantarctic sector of the Southern Ocean. Judging from the better structural fit of UK37 SST records with other subantarctic surface proxy records, including foraminiferal 18O and SST records inferred from diatom- and foraminiferal assemblages, it appears that the UK37 index results in more plausible paleo SST records in this region, as opposed to the commonly used UK 37 index. The GDGT index (TEX86 and TEX86L) values in the subpolar and polar core-tops (with overlying SSTs of -2 to 17°C) are not highly correlated (r2 values < 0.3) to the annual mean WOA09 SST. Plotting these indices ... Doctoral or Postdoctoral Thesis Southern Ocean Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) Pacific Southern Ocean |
institution |
Open Polar |
collection |
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) |
op_collection_id |
ftsubbremen |
language |
English |
topic |
sea surface temperature alkenone GDGT UK37 TEX86 Southeast Pacific 550 550 Earth sciences and geology ddc:550 |
spellingShingle |
sea surface temperature alkenone GDGT UK37 TEX86 Southeast Pacific 550 550 Earth sciences and geology ddc:550 Ho, Sze Ling Reconstructing sea surface temperature in the South Pacific using organic proxies |
topic_facet |
sea surface temperature alkenone GDGT UK37 TEX86 Southeast Pacific 550 550 Earth sciences and geology ddc:550 |
description |
Sea surface temperature (SST), at the interface between the atmosphere and the ocean, is an important element in the global climate system. Accurate estimates of past SSTs are indispensable for studying global climate and for validating the numerical models used for projections of future climate. SSTs prior to the instrumentation era could be reconstructed using climatically sensitive biomarkers such as alkenones and glycerol dialkyl glycerol tetraethers (GDGTs). Herein I use marine sediments, both core-tops and long piston cores, to further examine the applicability of organic SST proxies derived from the aforementioned biomarkers, with an emphasis on the relatively under-studied subantarctic Southeast Pacific. The appraisal of these proxies is based on the correlation of the core-top proxy index values with present-day climatological SST, and the comparison of the SST records inferred from these proxies with other regional SST records. The alkenone index (UK37 and UK 37) values in the South Pacific core-tops display linear relationships with climatological World Ocean Atlas 2009 (WOA09) SST at low temperatures (1 -12°C), with equally high r2 values (>0.93). These results suggest that both alkenone indices are highly correlated to SST even at high latitudes, rendering them appropriate for reconstructing SST in the subantarctic Pacific. However, these indices yield different Pleistocene SST patterns for study sites in the subantarctic sector of the Southern Ocean. Judging from the better structural fit of UK37 SST records with other subantarctic surface proxy records, including foraminiferal 18O and SST records inferred from diatom- and foraminiferal assemblages, it appears that the UK37 index results in more plausible paleo SST records in this region, as opposed to the commonly used UK 37 index. The GDGT index (TEX86 and TEX86L) values in the subpolar and polar core-tops (with overlying SSTs of -2 to 17°C) are not highly correlated (r2 values < 0.3) to the annual mean WOA09 SST. Plotting these indices ... |
author2 |
Tiedemann, Ralf Mollenhauer, Gesine |
format |
Doctoral or Postdoctoral Thesis |
author |
Ho, Sze Ling |
author_facet |
Ho, Sze Ling |
author_sort |
Ho, Sze Ling |
title |
Reconstructing sea surface temperature in the South Pacific using organic proxies |
title_short |
Reconstructing sea surface temperature in the South Pacific using organic proxies |
title_full |
Reconstructing sea surface temperature in the South Pacific using organic proxies |
title_fullStr |
Reconstructing sea surface temperature in the South Pacific using organic proxies |
title_full_unstemmed |
Reconstructing sea surface temperature in the South Pacific using organic proxies |
title_sort |
reconstructing sea surface temperature in the south pacific using organic proxies |
publisher |
Universität Bremen |
publishDate |
2012 |
url |
https://media.suub.uni-bremen.de/handle/elib/429 https://nbn-resolving.org/urn:nbn:de:gbv:46-00102943-16 |
geographic |
Pacific Southern Ocean |
geographic_facet |
Pacific Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://media.suub.uni-bremen.de/handle/elib/429 urn:nbn:de:gbv:46-00102943-16 |
op_rights |
info:eu-repo/semantics/openAccess Bitte wählen Sie eine Lizenz aus: (Unsere Empfehlung: CC-BY) |
op_rightsnorm |
CC-BY |
_version_ |
1766207750792019968 |