Title: African dust deposition to Florida: How well do dust models perform?
Abstract: Models, widely used to estimate dust deposition to the oceans, have not been adequately tested because of the dearth of long-term measurements of dust deposition rates. Here we present the results of a three year deposition program in a nine-station network distributed throughout the State of Florida which is impacted by African dust every year. The deposition rates of soil-related elements (Al, Fe, Mn) were strongly correlated and exhibited an extremely strong summer maximum that closely matched concurrently-measured dust concentrations in Miami. The deposition rates of Al, Fe and Mn at all sites were remarkably uniform. The deposition rates of dust, based on Fe measurements, were compared with those from nine AEROCOM models. Dust models correctly characterized the seasonal cycle of deposition but most grossly underestimated summer deposition and they tended to produce latitudinal gradients that were not observed in the network. There is a clear need to better understand the treatment of deposition processes in models.