Relationship of Aerosols and Tropical Cyclogenesis Over the Eastern Atlantic Ocean Basin for Recent Hurricane Seasons

Although the large-scale dynamics of Tropical Cyclone (TC) formation is well understood, the impact of aerosols or dust particles on Tropical Cyclogenesis (TC-genesis) remains elusive.

Using NASA’s CALIPSO Satellite, aerosol vertical distribution was studied in the tropical cyclone (TC) main development region (MDR) during the recent active hurricane seasons (2015-2018). Monthly climatology of aerosol concentration was developed to understand the magnitude of changes throughout the Atlantic Hurricane season. The Total Attenuated Backscatter (TAB) at 532nm, was used to illustrate the frequency and magnitude of the aerosol distribution in the tropical cyclogenesis region. The MDR was further divided into two domains to show the gradient of aerosol along the transport paths of African Easterly waves. In this analysis, a combination of extinction quality flag, cloud fraction, and CAD scores were used to screen out the impact of clouds. The distribution of average aerosol and dust percentage from the time of active cyclogenesis was compared and quantified to climatology.To further the study, other variables such as sea surface temperature (SST) and vertical wind-shear differences were considered to determine if the environment was conducive for development.

Additionally, we analyzed TAB latency between the initial dust outbreak events off the African coast to the interaction period of the TC. As the tropical cyclones propagate across the Atlantic Ocean a better understanding of development characteristics with respect to time was obtained. Furthermore, by numerically quantifying aerosol concentration during initial emission to the interaction period with the TC, the influence of direct and indirect atmospheric aerosols on tropical cyclogenesis will be established.