HBCU: Excellence in Research: Analysis and Modeling of the Ocean Spray Effects on Tropical Cyclone Dynamics

It is well-documented that hurricane track forecasts have improved substantially over the recent decades, while forecasts of hurricane intensity change have lagged. Hurricane intensity is sensitive to a variety of factors, such as wind shear and the internal organization of the cyclone. One of the main uncertainties in research on hurricane behavior is the role of ocean spray on the system. Ocean spray affects the air-sea exchange of momentum, heat, and moisture. Direct observations in these conditions are rare and very difficult, so most of the understanding about ocean spray is from calmer conditions or numerical models. In this project, the PI plans to come at the problem from the perspective of fundamental physical conservation laws, progressively building a more elaborate mathematical model of sea spray. The eventual societal impact of this work would be through improvements in numerical weather models, which would translate to better forecasts of hurricanes and their impacts. The project would also represent the enhancement of research and education at a Historically Black College and University.

The PI plans to develop a mathematically rigorous and physically sound model of a marine atmospheric boundary layer laden with evaporating sea spray and perform numerical and asymptotic analyses of the model to create an efficient parameterization of a sea spray effect on tropical cyclone dynamics and structure. The starting point will be a set of fundamental conservation laws which will be applied to systematically develop progressively more comprehensive models in such a way that the influence of newly added physical factors is clearly identifiable. Under the first objective of developing the model, the PI plans the derivation of macro-scale, multi-fluid transport equations, formulation of the multi-phase turbulence model, and analysis of the droplet population dynamics. The asymptotic and numerical analysis of the model would be conducted by performing regular asymptotic expansions, singular asymptotic expansions, and numerical analysis of the model.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.