Grant: Discovery Grants Program - Individual

Prediction of the optical properties of the upper ocean is of central importance in oceanography. These properties regulate the penetration of visible radiation with ramifications for both physical and biological oceanographic processes. Solar radiation absorbed in the upper layers heats and stabilizes the ocean; as a result, variability in the rate of attenuation of visible radiation plays a strong role in the upper ocean thermal structure and dynamics. Absorbed radiation is responsible for driving the photosynthetic process on which life in the sea depends. For applied interests, the attenuation of visible wavelengths dictates the effective transmission from point and diffuse sources either at the sea surface, or at depth. The goals of my research program are to examine both the sources of variability in ocean optical properties, and to evaluate the effect of this variability on both oceanic biogeochemical cycles and the physical climate interactions: 1. Elucidation of the sources of variability in the optical properties of the ocean. Sources include biological processes, fluid dynamical processes, non-living, but optically active ocean constituents (e.g. bubbles), and the physical properties of the radiance field as influenced by the atmosphere, the air-sea interface, and the net effects of radiative transfer within the ocean interior. 2. Evaluation of the role of variability in oceanic optical properties in determining rates of primary production in the sea, particularly on scales appropriate for the determination of the role of oceanic biogeochemical processes in the global carbon cycle. 3. Evaluation of the role of variability in oceanic optical properties in determining the thermal structure and dynamics of the upper ocean. My approach includes theoretical analysis, numerical simulations, laboratory experiments, satellite observations and extensive sea-going field investigations. The resulting increased skill in prediction will significantly influence our understanding of biological, physical and climate processes in the ocean.