The Response of Atlantic Tropical Cyclones to Suppression of African Easterly Waves. Issue 1 (15th January 2018)

• Record Type: Journal Article
• Authors: Patricola, Christina M.; Saravanan, R.; Chang, Ping
• Is Part Of: Geophysical research letters. Volume 45:Issue 1(2018)
• Page Start: 471
• Page End: 479
• Publication Date: 2018-01-15
• Subjects: tropical cyclones -- tropical cyclogenesis -- African easterly waves -- climate variability; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL076081
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Atlantic tropical cyclone (TC) genesis is strongly linked with African easterly waves (AEWs) on the synoptic time scale. However, the TC‐AEW relationship is unclear on interannual to climate time scales, and it is unknown whether AEWs are necessary to maintain climatological TC frequency, that is, whether TCs are limited by AEWs. We investigated the impact of AEW suppression on seasonal Atlantic TC activity using a 10‐member ensemble of regional climate model simulations in which AEWs were either prescribed or removed through the lateral boundary condition. The climate model experiments produced no significant change in seasonal Atlantic TC number, indicating that AEWs are not necessary to maintain climatological basin‐wide TC frequency even though TCs readily originate from these types of disturbances. This suggests that the specific type of "seedling" disturbance is unimportant for determining basin‐wide seasonal Atlantic TC number and that in the absence of AEWs, TCs will generate by other mechanisms. The results imply that changes in the presence of AEWs may not be reliable predictors of seasonal variability and future change in Atlantic TC frequency. Key Points: African easterly wave suppression produced no change in seasonal Atlantic tropical cyclone number in regional model simulations Atlantic TCs are not limited by AEWs on season‐climate time scales and will generate by other mechanisms in the absence of AEWs AEWs are not a reliable predictor of variability and change in basin‐wide Atlantic TC frequency but may be important regionally