91探花

Ocean carbon uptake: in my DFG , I am investigating the physical drivers of the Southern Ocean carbon sink in present and future climate conditions. I use and further developed global ocean biogeochemistry models with resolutions ranging from 0.5潞 to 0.25潞 to 0.1潞 in the ACC regime (Fig. 2).

Research highlights:

• Model resolution affects the Southern Ocean carbon uptake: eddy-rich simulations have higher anthropogenic carbon uptake than coarse models with an eddy parameterization, because of different interior density structures and circulation (ongoing work).
• Wind stress drives most of interannual and decadal changes in Southern Ocean carbon uptake at subpolar latitudes (through changes in upwelling), buoyancy forcing drives most of the variability at middle latitudes (through changes in mixing) (ongoing work).
• I contributed to RECCAP-2 assessment of  and in particular to the .
• A novel adaptive machine learning method tailored to consider underlying ocean data distribution to recognize clusters was devised to detect and track carbon uptake regimes over the global ocean (PhD project of Sweety Mohanty). 

Bio-physical interactions in the climate system: Since my graduate studies, I was fascinated by how ocean, climate and marine biogeochemistry interact with each other on different spatio-temporal scales.

Research highlights:

• Phytoplankton radiative heating affects sea surface temperature and climate, and may amplify the greenhouse effect by enhancing atmospheric water vapor (). 
• The marine biogeochemical responses to the North Atlantic Oscillation are governed by different mechanisms on interannual time scales (vertical mixing dominates) and decadal time scales (slow ocean circulation adjustments dominate) ().
• In the North Pacific Ocean the flow of carbon to the microbial loop is enhanced under global warming, and phytoplanktonic stoichiometry becomes nutrient-depleted ().
• Oxygen variability and trends over the past 60 years vary widely on a regional scale in connection to local changes in solubility, ventilation and remineralization (Master Thesis of Helene Hollitzer).