| dc.contributor.advisor | Wilhelms, Frank Prof. Dr. | |
| dc.contributor.author | Dallmayr, Remi | |
| dc.date.accessioned | 2022-09-16T07:50:43Z | |
| dc.date.available | 2022-09-23T00:50:12Z | |
| dc.date.issued | 2022-09-16 | |
| dc.identifier.uri | http://resolver.sub.uni-goettingen.de/purl?ediss-11858/14247 | |
| dc.identifier.uri | http://dx.doi.org/10.53846/goediss-9444 | |
| dc.language.iso | eng | de |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | |
| dc.subject.ddc | 910 | de |
| dc.subject.ddc | 550 | de |
| dc.title | Towards a high-quality interannual to millennial ice-core based temperature reconstruction for East-Antarctica | de |
| dc.type | cumulativeThesis | de |
| dc.contributor.referee | Wilhelms, Frank Prof. Dr. | |
| dc.date.examination | 2021-12-10 | de |
| dc.description.abstracteng | Instrumental observations of climate cover only the past ~200 years. Our knowledge about
historical natural climate variability beyond this time is exclusively based on climate proxies,
stored within natural archives. The polar ice sheets of Greenland and Antarctica have formed by
continuous accumulation of snow over > hundred-thousand of years, recording local climate
conditions such as the air temperature by means of the isotopic composition of the water molecules
composing the snow and ice. However, in regions with very little snow accumulation, multiple
processes hamper the interpretation of isotopic data in terms of climate variations and temperature
reconstructions from ice-cores from the East Antarctic Plateau are still highly uncertain on decadal
to millennial timescales. One approach to overcome the local spatial noise in isotope records was
to stack several independent vertical profiles of a specific site. In order to extend this approach
into space and time, innovative developments are required to enable (1) the extensive spatial
sampling of the snowpack in the field, (2) the temporal analysis providing high-quality isotope
records of an increasing amount of profiles from Antarctic snow- and ice-cores.
As a part of the AWI Strategyfund project COMB-i, this dissertation addresses the technical
development of tools to meet both requirements and to be applicable to the East Antarctic
snowpack and ice column:
1) Spatially, I developed a novel sampling technique for a fast and precise sampling of the snow,
allowing to investigate the spatial variability of the isotopic composition of the snowpack. We
applied this new tool in a study to regionally investigate the relationship between local topography,
accumulation rate and isotopic composition. We identify a new mechanism leading to a non-climatic
variability in isotopic records retrieved from ice cores, which may impact a large area of
the East Antarctic Plateau. Such a finding will improve the interpretation of existing ice-core
records, affect the choice of future ice-core drilling site, and contribute to develop statistical
models for non-climatic variations of water isotope record.
2) Temporally, I enabled the analysis of isotopic composition with high-precision of snowpack
profiles using the Continuous Flow Analysis (CFA) technique. This will allow high-pace
measurement of snow-cores, and hence increase statistics of temporal analyzes in order to
ultimately strengthen the understanding of the isotopic signal formation. The CFA setup was
further applied to generate high-quality paired records of stable water isotopes and chemical
impurities along the top 70-meters of an ice-core from East Antarctica. The data produced will
foster the newly developed method within the COMB-i project to utilize impurity records to
improve the temperature reconstruction from East Antarctic ice-cores.
Overall, through technical innovations and their application, this thesis contributes to push
further the limit towards high-quality temperature records on the interannual to millennial time
scales in East Antarctica. | de |
| dc.contributor.coReferee | Pack, Andreas Prof. Dr. | |
| dc.subject.eng | Temperature reconstruction | de |
| dc.subject.eng | Isotopic composition | de |
| dc.subject.eng | Ice and snow cores | de |
| dc.subject.eng | East Antarctic Plateau | de |
| dc.identifier.urn | urn:nbn:de:gbv:7-ediss-14247-9 | |
| dc.affiliation.institute | Fakultät für Geowissenschaften und Geographie | de |
| dc.subject.gokfull | Meteorologie und Klimatologie (PPN623607115) | de |
| dc.description.embargoed | 2022-09-23 | de |
| dc.identifier.ppn | 1816896950 | |
| dc.identifier.orcid | 0000-0001-6059-0098 | de |
| dc.notes.confirmationsent | Confirmation sent 2022-09-16T08:15:02 | de |