Impact of assimilated and interactive aerosol on tropical cyclogenesis

This article investigates the impact of Saharan dust on the development of tropical cyclones in the Atlantic. A global data assimilation and forecast system, the NASA GEOS‐5, is used to assimilate all satellite and conventional data sets used operationally for numerical weather prediction. In addition, this new GEOS‐5 version includes assimilation of aerosol optical depth from the Moderate Resolution Imaging Spectroradiometer. The analysis so obtained comprises atmospheric quantities and a realistic 3‐D aerosol and cloud distribution, consistent with the meteorology and validated against Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation and CloudSat data. These improved analyses are used to initialize GEOS‐5 forecasts, explicitly accounting for aerosol direct radiative effects and their impact on the atmospheric dynamics. Parallel simulations with/without aerosol radiative effects show that effects of dust on static stability increase with time, becoming highly significant after day 5 and producing an environment less favorable to tropical cyclogenesis. Key Points Global data assimilation of satellite‐derived aerosol optical depths Simulation of the direct radiative effects of dust on tropical cyclogenesis Improved understanding of the role of dust on tropical cyclone development