The Role of Airborne Dust in the Simulation of Global Tropical Cyclone Activity

This study is a continuation of ongoing work to examine how well tropical cyclone (TC) characteristics are captured in various versions of the Community Atmosphere Model version 5 (CAM5).  The main focus of this work is to better understand climate controls on TC intensity, genesis location and frequency.  For this work CAM5, a comprehensive atmospheric general circulation model, is configured with a horizontal grid spacing of approximately 28 km and is forced with prescribed sea-surface temperatures (SSTs) and greenhouse gases.  This investigation includes a comparison of TC activity with two different aerosol treatments within the CAM5 framework.  In particular, we explore the impact of airborne dust on the formation and development of TCs by modifying the prognostic aerosol formulation to inhibit dust emissions (i.e., no airborne dust) globally.  In general, we find an increase in overall TC activity at all intensity levels in model simulations with no dust; this is particularly true in the North Atlantic basin.  This increase in storm frequency is explored in detail in this study.