Relationship of Dust Aerosols and Tropical Cyclogenesis over the Eastern Atlantic Ocean Basin

Abstract

Although the large-scale dynamics of tropical cyclone (TC) formation is well understood, the impact of aerosols, especially dust particles, on tropical cyclogenesis (TC-genesis), remains elusive. This study investigated the aerosol vertical distribution in the TC main development region (MDR) during the recent active hurricane seasons (2015-2018) using observations from NASA’s CALIPSO satellite was investigated. The total attenuated backscatter (TAB) at 532nm was observed by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP Lidar) onboard CALIPSO was used to illustrate the distribution and magnitude of the aerosol vertical distribution in the TC-genesis region. The MDR was further divided into two Domains to better describe the aerosol concentrations along the paths of African Easterly Waves. An agreement of extinction quality flag, cloud fraction, and cloud-aerosol discrimination (CAD) scores was used to filter out the impact of clouds. Other variables such as sea surface temperature (SST) and vertical wind-shear differences were examined to determine if the large-scale environment was conducive for development. Furthermore, by analyzing aerosol concentration during initial emission to the interaction period with the TC, the role of atmospheric aerosols in tropical cyclogenesis may be established. The results indicated tropical cyclogenesis still took place for all AEW’s in dust conditions while the environmental variables were favorable indicating that dust aerosols may not play a significant role in inhibiting the genesis process of TCs.