Dr. Bronwyn Cahill 

This twin fellowship application supports Prof. John Wilkin’s HWK project to incorporate multispectral ocean color observations from satellites into an advanced data assimilative ocean circulation modelling framework coupled to biogeochemical and ecosystem models of coastal waters. The twin fellowship will support the development of a generic ocean color remote sensing reflectance observation operator. This so-called observation operator calculates the remote sensing reflectance that a satellite would see due to absorption and scattering of visible light by simulated plankton, organic matter, and sediments. Then, by inverting this operator using formal mathematical methods, satellite remote sensing reflectance observations from satellites can constrain the vertical distribution of bio-optically active constituents in the water column, and potentially distinguish the relative abundance of different phytoplankton species and organic matter. The project thus entails not only regional ocean hydrodynamic modeling and advanced variational methods for data assimilation, but also the implementation of a visible light radiative transfer model and appropriate formulation of its absorption and scattering parameterizations.