Dr. Mick Follows, senior research scientist in EAPS and a leader of the Darwin Project at MIT, will will give a presentation in the Earth System Initiative spring seminar series. Abstract: Marine phytoplankton mediate the ocean carbon cycle and are at the base of the marine food chain. Dr. Follows will present a global ocean model with a self-organizing representation of marine phytoplankton communities, and use it to elucidate the role of physical ocean circulation and variability in regulating diversity and community structure. The model exhibits low diversity in polar regions, higher diversity in subtropical latitudes, and the highest diversity in regions of energetic circulation features. These patterns are consistent with current sparse observational data, and may be understood in terms of variability in both the physical environment and transport by swift boundary currents.