Alexa Fischer

Research Focus:

The long-term global cooling trend during the latest Cretaceous was interrupted by an intense global warming episode at ~69 Ma known as the mid Maastrichtian event (MME). Changes in oceanic circulation, particularly a change in thermohaline circulation patterns, have been proposed to be one of the main drivers of the MME. Nevertheless, the driving mechanisms, timing, character, and consequences of the circulation change are still up for debate. My research focuses on understanding the climatic patterns causing the MME, as well as on unraveling the drivers of the potential circulation change during the MME and on further assessing the biotic and climatic effects of the MME.

For that purpose, a multiproxy approach is used:

-       Sea Surface Temperature (SST) reconstructions from planktic foraminiferal Mg/Ca

-       Bottom Water temperature (BWT) reconstruction from benthic foraminiferal Mg/Ca

-       Stable isotope analysis (d¹³C and d¹⁸O) on planktic and benthic foraminifera

Scientific Career and Education:

• since 09/2021: PhD position at the Institute of Earth Sciences of Ruprecht-Karls University, Heidelberg. Supervisor: Prof. Dr. Oliver Friedrich
• 08/2021: M.Sc. Thesis: “Single Foraminifera Na/Ca and Mg/Ca analyses derived from Globigerinoides ruber using femtosecond-LA-ICP-MS” Supervisors: Dr. Ralf Schiebel, Prof. Dr. D. Scholz
• 04/2020 - 08/2021: Master of Science Geosciences, Johannes-Gutenberg University Mainz, Germany
• 04/2020: B.Sc. Thesis: “Nitrogen isotopes in the marine environment” Supervisors: Dr. Ralf Schiebel, Prof. Dr. D. Scholz
• 10/2016 - 04/2020: Bachelor of Science Geosciences, Johannes-Gutenberg University Mainz, Germany

Research Experience:

• 05/2017 – 08/2021: Research assistant, Max-Planck-Institute for Chemistry, Climate Geochemistry

Grants/Awards:

• 2022: ECORD Scholarship for the Urbino Summer School in Paleoclimatology (Urbino, Italy)

Conference Contributions:

• Fischer, A., Friedrich, O., Bahr, A., Voigt, S. 2023. A new high resolution stable isotope record from the North Atlantic Ocean: a detailed insight into the mid-Maastrichtian event. EGU General Assembly, Vienna, Austria, 23/04/23 – 28/04/23 [Poster]
• Fischer, A., Friedrich, O., Bahr, A., Voigt, S. 2022. Are hyperthermal events a persistent feature of greenhouse climates? Joint IODP/ICDP Meeting 01/11/22 – 03/11/22 [Poster]
• Fischer, A., Friedrich, O., Bahr, A., Voigt, S. 2022. Are hyperthermal events a persistent feature of greenhouse climates? 14^th International Conference on Paleoceanography (ICP14), Bergen, Norway, 29/08/22 – 2/09/22 [Poster]
• Fischer, A., Friedrich, O., Bahr, A., Voigt, S. 2022. Are hyperthermal events a persistent feature of greenhouse climates? 12^th international Conference on Climatic and Biotic Events of the Paleogene (CBEP12), Bremen, 22. – 25. Aug. 2022 [Poster]
• Fischer, A., Friedrich, O., Bahr, A., Voigt, S. 2022. Are hyperthermal events a persistent feature of greenhouse climates? Ecord Summer School, Urbino, 07/07/22 – 20/07/22 [Poster]
• Fischer, A., Aardema, H.M., Smart, S.M., Repschläger, J., Martinez-Garcia, A., Scholz, D., Schiebel, R., Haug, G.H., 2020. Foraminifera-bound ¹⁵N and NO₃^{- 15}N in the North Atlantic Ocean. S/Y-Eugen Seibold conference [Poster].