000K utf8 1100 $c2005 1500 ger 2050 urn:nbn:de:gbv:8-diss-13723 3000 Kirch, Anja 4000 Untersuchungen zur Rekonstruktion des Partialdruckes von Kohlendioxid anhand von Coccolithophoridenblüten im Nordatlantik : Biomarker Alkenone und deren Kohlenstoffisotopie$hChristian-Albrechts-Universität zu Kiel [Kirch, Anja] 4030 Kiel$nChristian-Albrechts-Universität zu Kiel 4209 The dissertation deals with methodological and field studies of alkenones and their carbon isotopes in the North Atlantic (Madeira Basin). The methodological studies focussed on comparison of measurements with gas chromatography with flame ionisation detection and gas chromatography coupled to mass spectrometry. It was possible to separate and detect three C37-, five C38- und five C39-alkenones with a single measurement, even at low concentrations. A goal of the field studies was to determine the original carbon isotope values in alkenones at the time of synthesis during blooms of coccolithophorids. 1)Modifications of this primary delta13C- alkenones-values in the water column were followed up to the sediment traps at 2,000 m and 3,050 m. 2)The values of the underlying sediments were considered. The controversial use of the delta13C-alkenones-values for paleoreconstruction of the partial pressure of carbondioxid was critically examined. Parallel behaviour in the development of temperature and delta13C-alkenones-values were observed for all measured alkenones. Dependencies of different delta13C- alkenones-indices of the temperature were established. 4950 https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-13723$xR$3Volltext$534 4961 https://macau.uni-kiel.de/receive/diss_mods_00001372 5051 550 5550 alkenone 5550 Biomarker 5550 C02 5550 carbon isotopes 5550 coccolithophorid 5550 Coccolithophoridae 5550 delta13C 5550 Enone 5550 Klimaänderung 5550 Kohlendioxid 5550 Kohlenstoffisotop 5550 North Atlantic 5550 Partialdruck 5550 partial pressure of carbondioxid 5550 sediment 5550 sediment trap 5550 surface water 5550 Wasserblüte