Current Research:​
The effect of marine phytoplankton on ocean anoxia
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Figure: Ecological Provinces from a Darwin Model, MIT general circulation model computer simulation – Each color represents a different distinct combination of the most dominant phytoplankton function. Image Credit: Oliver Jahn, Stephanie Dutkiewicz, Chriss Hill and Mick Follows, MIT.
The geologic phosphate cycle
Phosphate is an essential nutrient for all forms of life. Over geologic time scales (millions of years) oceanic phosphate levels drive rates of primary productivity, burial of organic carbon, and oxygen production. Using newly developed biogeochemical model, we find that oceanic phosphate levels are regulated by the relative interplay between the seafloor and continental weathering (Figure 1).
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Figure 1. The effect of continental vs. seafloor weatherability on the phosphate and calcium inputs to the ocean. Illustration by Dr. Miguel Frada.
The BioGeo model
During my PhD at the Weizmann Institute of Science, me and my PhD advisor, Prof. Itay Halevy developed the 'BioGeo' model. The BioGeo model simulates the evolution of carbon, oxygen, phosphorous, and alkalinity, between the ocean, atmosphere, and Earth’s reservoirs (Figure 2).
Using this model, we found that rate of seafloor weathering highly influenced geologic phosphate concentration, and we constrained the paleo Redfield ratio!
The model is written in MATLAB and is available here.
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Figure 2. Model scheme. The long-term cycling of phosphate, carbon, oxygen, calcium, and the sedimentary pools of organic matter and carbonate rocks. Black arrows represent fluxes between the pools, where the dashed lines are weathering fluxes.