Projects Uni Bremen
MArine radioCArbon Reservoir Alter (MACARA)
DFG Project 1.4.2022-31.3.2025 by Gerrit Lohmann
Team: Gerrit Lohmann, Martin Butzin, Edouard Bard
We reconstruct the distribution of radiocarbon at the sea surface with unprecedented temporal and spatial resolution and simulate it using a novel multi-scale climate radiocarbon model. This will allow marine data to be corrected and hypotheses about abrupt climate changes during the last ice age to be tested.
The Marine Reservoir Effect in C-14 is a phenomenon that works as a proxy for several climate-related parameters. Still, the MRE remains understudied in many locations around the globe, limiting our understanding of the global carbon cycle and how it responds to climate change. Taking advantage of the state-of-the-art facilities available in the host institutions, the investigators will be able to achieve high-quality data that are much needed at this moment of profound changes in climate. Indeed, by providing the quantification of the MRE for key locations in the main ocean basins, the MARCARA project aims to fill a long-standing gap in radiocarbon research. The project combines both experimental data acquired in the lab with numerical modelling, which is a powerful combination that will strengthen the outcomes of the project. This type of approach has been successfully used in climate research and remains crucial for the understanding of climate evolution in different timescales. Focusing on the last deglacial, which is a key period for understanding the Earth Climate System, the project is an ambitious undertaking that has the potential to enhance our knowledge of the climate system stimulating new research on a variety of topics, ranging from archaeology and cultural heritage to the geosciences. By providing these data, the MARCARA project is likely to positively impact the radiocarbon community helping to unravel the mechanisms involved in climate variations over the past.
- Atmospheric radiocarbon concentrations in terms of F14C (the
fractionation-corrected and normalized 14C/12C ratio) according to the
Hulu Cave speleothem record (Cheng et al., 2018; Southon et al., 2012).
Upper and lower curves span the uncertainty range (mean values ±2σ). b)
Ensemble simulations of marine 14C for the past 50 kyr forced with
atmospheric F14C according to Hulu Cave, shown is the period where 14C
dating is not further constrained through continuous tree ring 14C
records. (c) Corresponding ensemble simulations of marine 14C expressed
as 14C age with respect to the contemporaneous atmosphere (the Marine
Reservoir Age); values are averaged between 50°N and 50°S. CS, GS, and
PD specify different ocean states with weak, intermediate, and strong
overturning (Butzin et al., 2020). (d) Marine reservoir age simulated
for the Last Glacial Maximum; shown is the ensemble median of the
transient simulations. Filled circles are foraminifera-based marine
reservoir ages compiled by Skinner et al. (2017). Source
Publications:
German version:
Wir werden die Verteilung von Radiokohlenstoff an der Meeresoberfläche mit bisher nicht gekannter zeitlicher und räumlicher Auflösung rekonstruieren und mit Hilfe eines neuartigen multiskaligen Klima-Radiokohlenstoff-Modells simulieren. Dadurch können marine Daten korrigiert und Hypothesen über abrupte Klimaveränderungen während der letzten Eiszeit getestet werden.
DFG Projekt: MArine radioCArbon Reservoir Alter
EXC 2077: The Ocean Floor – Earth’s Uncharted Interface
Subject Area: Atmospheric Science, Oceanography and Climate Research Geology and Palaeontology, Mineralogy, Petrology and Geochemistry
Term: since 2019