Complexity Explorer Santa Few Institute

The Physics of Death and Burial

mentors: Daniel Muratore and Chris Kempes

---

The daily lives and deaths of more than 10^29 microbial cells in Earth’s oceans sets the balance of ocean carbon uptake and exchange with the atmosphere, rivaling photosynthesis conducted by all land plants combined and contributing to a long-term carbon reservoir in the deep ocean exceeding our known fossil fuel reserves by ten times. How carbon from dead phytoplankton cells - whether blown apart by a viral infection or condensed into zooplankton feces - aggregates and sinks remains to be adequately characterized by biophysical models and synthesized across rich oceanographic datasets. We propose a suite of project possibilities, ranging from analysis of nonlinear dynamical systems to agent-based models to computational analysis of empirical data. In each, we aim to characterize simple mechanistic rules that structure the distribution of particle sizes and fluxes across the ocean. Join us in any combination of: 1) extending a nonlinear dynamical model of particle aggregation from simple spheres to complex fractal aggregates to understand the time evolution of particle size and velocity distributions, 2) coding an individual-based multiparticle collision model to study emergent scaling processes in the size and mass distributions of diffusing particles in seawater, or 3) searching for structuring rules and universality in a global compendium of ocean carbon flux and particle size distribution datasets. For all projects, SFI postdoctoral fellow Daniel Muratore has access to datasets from collaborations with the long-term Hawaii Ocean Time Series and a personal dataset of electron microscopic images of individual sinking aggregates collected on a transect crossing the Pacific ocean from Hawaii to French Polynesia.