Alexa Fischer

Research Focus:

My research is situated in marine paleoclimatology and paleoceanography and focuses on reconstructing past oceanographic and climatic variability from marine sediment records. I use geochemical proxy data from benthic and planktonic microfossils to investigate changes in ocean temperature, circulation, and ice volume, and to assess how surface and deep-ocean processes are coupled over geological timescales.

A central aspect of my work is the combined interpretation of stable isotope records and temperature proxies, supported by robust age models and quantitative time-series analysis. Through a multi-proxy approach, my research contributes to a better understanding of ocean–climate interactions and the behavior of the climate system under warm and transitional conditions.

Scientific Career and Education:

• since 06/2025: Postdoctoral Researcher at the Institute of Earth Sciences of Ruprecht-Karls University, Heidelberg
• 09/2021 - 06/2025 : 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)
• 2025: Geology Foundation Award (Preis der Geologie-Stiftung) – awarded for the best PhD thesis: “Unraveling Late Cretaceous climate and ocean dynamics: A multi-proxy approach using benthic and planktic foraminifera”.

Publications (peer-reviewed):

2026:

1. Creac’h, L., Brzelinski, S., Lippold, J., Gutjahr, M., Frank, M., Fischer, A., Friedrich, O. Short-term Antarctic ice-sheet dynamics during the late Oligocene. Commun Earth Environ 7, 189 (2026). 

   https://doi.org/10.1038/s43247-026-03217-4

2025:

1. Fischer A., Batenburg, S.J., Bahr, A., Voigt, S.., Rheinberger, A., Schmickal, S., Rheinberger, S., Greule, M., Rheinberger, S., Friedrich, O. 2025. Precession-paced late Maastrichtian bottom-water dynamics. Commun Earth Environ 6, 239. 

   https://doi.org/10.1038/s43247-025-02219-y

2024:

1. Fischer, A., Schiebel, R., Jochum, K.P., Heis, L., Arns, A., Aardema, H., Slagter, H., Calleja, M.LI., Levy, N., Stoll, B., Walter, D., Weis, U., Repschläger, J., Haug, G.H. 2024. Single chamber Mg/Ca analysis of Globigerinoides ruber for paleo-proxy calibration using femtosecond LA-ICP-MS. Scientific Data 11, 583. hhtps://doi.org/10.1038/s41597-024- 03402-0
2. Schiebel, R., Aardema, H., Calleja, M.LI., Dragoneas, A., Heins, L., Hrabe de Angelis, I., Pöhlker, C., Slagter, H., Vonhof, H., Walter, D., Arns, A.I., Adolphs, N., Auderset, A., Basic, S., Bieler, A., Brüwer, J.D., Chaabane, S., Cheng, Y., Chilinski, M.T., Cybulski, J.D., Disper, T., Duprey, N., Eichele, G., Fiedler, B., Fischer, A., et al. 2024. Preface: Special Issue on Probing the Open Ocean with the Research Sailing Yacht Eugen Seibold for Climate Geochemistty. Journal of Geophysical Research: Atmospheres, 129. 

   https://doi.org/10.1029/2023JD040581