Proxy signal formation in palaeoclimate archives
Throughout the last ~3 million years, the Earth's climate system was characterised by cycles of glacial and interglacial periods. The current warm period, the Holocene, is comparably stable and stands out from this long-term cyclicality. However, since the industrial revolution, the climate has...
Main Author: | |
---|---|
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
Published: |
2023
|
Subjects: | |
Online Access: | https://publishup.uni-potsdam.de/frontdoor/index/index/docId/58286 https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-582864 https://doi.org/10.25932/publishup-58286 https://publishup.uni-potsdam.de/files/58286/zuhr_diss.pdf |
id |
ftubpotsdam:oai:kobv.de-opus4-uni-potsdam:58286 |
---|---|
record_format |
openpolar |
spelling |
ftubpotsdam:oai:kobv.de-opus4-uni-potsdam:58286 2023-06-06T11:58:41+02:00 Proxy signal formation in palaeoclimate archives Proxy-Signalbildung in Paläoklimaarchiven Zuhr, Alexandra 2023 application/pdf https://publishup.uni-potsdam.de/frontdoor/index/index/docId/58286 https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-582864 https://doi.org/10.25932/publishup-58286 https://publishup.uni-potsdam.de/files/58286/zuhr_diss.pdf eng eng https://publishup.uni-potsdam.de/frontdoor/index/index/docId/58286 urn:nbn:de:kobv:517-opus4-582864 https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-582864 https://doi.org/10.25932/publishup-58286 https://publishup.uni-potsdam.de/files/58286/zuhr_diss.pdf https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess ddc:550 Institut für Geowissenschaften doctoralthesis doc-type:doctoralThesis 2023 ftubpotsdam https://doi.org/10.25932/publishup-58286 2023-04-16T22:34:15Z Throughout the last ~3 million years, the Earth's climate system was characterised by cycles of glacial and interglacial periods. The current warm period, the Holocene, is comparably stable and stands out from this long-term cyclicality. However, since the industrial revolution, the climate has been increasingly affected by a human-induced increase in greenhouse gas concentrations. While instrumental observations are used to describe changes over the past ~200 years, indirect observations via proxy data are the main source of information beyond this instrumental era. These data are indicators of past climatic conditions, stored in palaeoclimate archives around the Earth. The proxy signal is affected by processes independent of the prevailing climatic conditions. In particular, for sedimentary archives such as marine sediments and polar ice sheets, material may be redistributed during or after the initial deposition and subsequent formation of the archive. This leads to noise in the records challenging reliable reconstructions on local or short time scales. This dissertation characterises the initial deposition of the climatic signal and quantifies the resulting archive-internal heterogeneity and its influence on the observed proxy signal to improve the representativity and interpretation of climate reconstructions from marine sediments and ice cores. To this end, the horizontal and vertical variation in radiocarbon content of a box-core from the South China Sea is investigated. The three-dimensional resolution is used to quantify the true uncertainty in radiocarbon age estimates from planktonic foraminifera with an extensive sampling scheme, including different sample volumes and replicated measurements of batches of small and large numbers of specimen. An assessment on the variability stemming from sediment mixing by benthic organisms reveals strong internal heterogeneity. Hence, sediment mixing leads to substantial time uncertainty of proxy-based reconstructions with error terms two to five times larger than ... Doctoral or Postdoctoral Thesis Planktonic foraminifera University of Potsdam: publish.UP |
institution |
Open Polar |
collection |
University of Potsdam: publish.UP |
op_collection_id |
ftubpotsdam |
language |
English |
topic |
ddc:550 Institut für Geowissenschaften |
spellingShingle |
ddc:550 Institut für Geowissenschaften Zuhr, Alexandra Proxy signal formation in palaeoclimate archives |
topic_facet |
ddc:550 Institut für Geowissenschaften |
description |
Throughout the last ~3 million years, the Earth's climate system was characterised by cycles of glacial and interglacial periods. The current warm period, the Holocene, is comparably stable and stands out from this long-term cyclicality. However, since the industrial revolution, the climate has been increasingly affected by a human-induced increase in greenhouse gas concentrations. While instrumental observations are used to describe changes over the past ~200 years, indirect observations via proxy data are the main source of information beyond this instrumental era. These data are indicators of past climatic conditions, stored in palaeoclimate archives around the Earth. The proxy signal is affected by processes independent of the prevailing climatic conditions. In particular, for sedimentary archives such as marine sediments and polar ice sheets, material may be redistributed during or after the initial deposition and subsequent formation of the archive. This leads to noise in the records challenging reliable reconstructions on local or short time scales. This dissertation characterises the initial deposition of the climatic signal and quantifies the resulting archive-internal heterogeneity and its influence on the observed proxy signal to improve the representativity and interpretation of climate reconstructions from marine sediments and ice cores. To this end, the horizontal and vertical variation in radiocarbon content of a box-core from the South China Sea is investigated. The three-dimensional resolution is used to quantify the true uncertainty in radiocarbon age estimates from planktonic foraminifera with an extensive sampling scheme, including different sample volumes and replicated measurements of batches of small and large numbers of specimen. An assessment on the variability stemming from sediment mixing by benthic organisms reveals strong internal heterogeneity. Hence, sediment mixing leads to substantial time uncertainty of proxy-based reconstructions with error terms two to five times larger than ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Zuhr, Alexandra |
author_facet |
Zuhr, Alexandra |
author_sort |
Zuhr, Alexandra |
title |
Proxy signal formation in palaeoclimate archives |
title_short |
Proxy signal formation in palaeoclimate archives |
title_full |
Proxy signal formation in palaeoclimate archives |
title_fullStr |
Proxy signal formation in palaeoclimate archives |
title_full_unstemmed |
Proxy signal formation in palaeoclimate archives |
title_sort |
proxy signal formation in palaeoclimate archives |
publishDate |
2023 |
url |
https://publishup.uni-potsdam.de/frontdoor/index/index/docId/58286 https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-582864 https://doi.org/10.25932/publishup-58286 https://publishup.uni-potsdam.de/files/58286/zuhr_diss.pdf |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_relation |
https://publishup.uni-potsdam.de/frontdoor/index/index/docId/58286 urn:nbn:de:kobv:517-opus4-582864 https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-582864 https://doi.org/10.25932/publishup-58286 https://publishup.uni-potsdam.de/files/58286/zuhr_diss.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.25932/publishup-58286 |
_version_ |
1767947525129502720 |