Characteristics and Trends of Atlantic Tropical Cyclones that do and do not Develop from African Easterly Waves
African easterly waves (AEWs) are known precursors to Atlantic tropical cyclones (TCs). Many previous studies have focused on TCs with AEW origins, while TCs without AEW origins have received less attention. This research examines the characteristics and trends of TCs with and without AEW origins by leveraging the historical record. We found that TCs with AEW origins are stronger, costlier, and experience more favorable environmental conditions than TCs without AEW origins. Additionally, we found that the increasing trend in Atlantic TCs is primarily driven by TCs with AEW origins.
Atlantic TCs can be both deadly and destructive, and these impacts may worsen with future climate change. TC development requires some type of initial disturbance, which is often an AEW in the North Atlantic, although other mechanisms can lead to TC formation, such as frontal low-pressure systems. In this study, we found statistically significant differences in the characteristics of TCs with and without AEW origins. TCs with AEW origins are stronger, costlier, and experience more favorable environmental conditions during their lifetimes. We also found that the historical increasing trend of Atlantic TCs is primarily driven by TCs with AEW origins, likely due to increasing AEW frequency and strength that may be related to a reduction in anthropogenic aerosols. These results demonstrate the importance of understanding TC origins as well as how changes in anthropogenic aerosols may impact TC trends.
In this study, we examined the characteristics and trends of Atlantic TCs that do and do not develop from AEWs. We used the observational record and reanalysis data to examine 43 years of Atlantic TCs and AEWs. We used objective tracking algorithms to identify AEWs and TCs in the reanalysis data between 1980-2022, and validated the TC tracks with observations. We found statistically significant differences in the characteristics of TCs with and without AEW origins. TCs with AEW origins are stronger and costlier, make landfall farther south, and experience more favorable environmental conditions during their lifetimes. Additionally, we found that the historical increasing trend in Atlantic TCs is primarily driven by TCs with AEW origins, likely due to increases in both the frequency and strength of AEWs over the past 43 years. Our results demonstrate a potential link between the increase in AEW and TC activity and a reduction in anthropogenic aerosols.