(Ivy Frenger, Wolfgang Koeve)

The ocean contributes to the uptake of about 25% of historical and current anthropogenic CO₂-emissions, thus mitigating climate change. The current marine CO₂ uptake is strongly dominated by physical-chemical processes while the biological carbon ‘pumps’, by way of that isolating carbon from exchange with the atmosphere in the ocean interior, are known to be of high relevance on long, multi-millennial timescales.

This group seeks to improve the understanding of the relative role and sensitivity to climate change of marine carbon storage, and in particular the relative role of the biological pumps, We consider varying  timescales from centennial to interglacial, using ocean circulation and Earth System models (e.g. UVic, FOCI), in combination with idealized tracer approaches.

Contributors:

• Ivy Frenger (role of ocean circulation and mixing in shaping marine carbon storage and uptake under climate change, with a particular focus on ocean mesoscale phenomena)
• Wolfgang Koeve (explicit quantification of the contribution of the biological carbon pump to the marine carbon sink and its feedback potential to atmospheric pCO₂ and Earth climate under Anthropocene transient conditions; development of idealized tracers and dedicated experimental protocols for such studies with the UVic ESM) 
• Malte Jürchott (quantification of changes in the  marine carbon sink within the context of possible future marine CDR deployment under different future CO₂-emission pathways in UVic ESM)
• Iris Kriest (co-chair of SCOR WG 161 ReMO: Respiration in the Mesopelagic Ocean; WP lead of EU Project OceanICU; testing sensitivities of global BGC model properties to parameterisations of particle flux length scales; global model assessment and calibration against various observations, among them sediment traps )
• Markus Schartau (spatio-temporal variations of the organic carbon and nitrogen content of suspended particulate matter (SPM) along transition from coastal areas to the open ocean)
• Tianfei Xue (relationship of export/export efficiency to physics-driven plankton dynamics) 
• Haichao Guo (evaluation of methods to estimate respiration rates and their changes)
• Andreas Oschlies (sensitivity of the ocean carbon cycle to changes in circulation and mixing)
• Hao-wei Wey (interaction between climate and marine/terrestrial carbon cycle with Earth system models and how it would be affected by future CDR deployment)
• Sina Acksen (assessment of the long-term stability of added alkalinity to the global oceans applied as marine CDR with special regard to the role of sediments in this process)
• Angela Landolfi (alumni & external collaborator) Quantification of BCP contribution to air-sea CO₂ partitioning under different climate scenarios; model estimates of return timescales of respired carbon)
• Estela Monteiro (external collaborator from the Marine Meteorology department) investigation of climate & temperature stabilization forcing scenarios, focusing Earth System responses, such as from the carbon cycle, and associated uncertainty)

If you are interested in collaborations or joining the group please do not hesitate to get in touch with us (ifrenger(at)geomar.de, wkoeve(at)geomar.de).