The Relationship Between African Easterly Waves and Tropical Cyclones in Historical and Future Climates in the HighResMIP‐PRIMAVERA Simulations

Abstract

Tropical cyclones (TCs) and their associated heavy precipitation, high winds, and storm surges are both deadly and destructive, leading to losses in the United States that can often exceed $1 billion for an individual event (Cerveny et al., 2017;NOAA, 2021;Yue et al., 2012). The genesis of these extreme events hinges on the co-occurrence of multiple environmental factors, including warm sea surface temperatures (SSTs), a moist mid-troposphere, weak vertical wind shear, and an initial precursor or "seed" disturbance (

African Easterly Wave Strength and Observed Atlantic Tropical Cyclone Genesis and Characteristics

“…Previous research has clearly shown a consensus that developing AEWs tend to be stronger than non‐developing AEWs (Agudelo et al., 2011; Bercos‐Hickey et al., 2023; Enyew & Mekonnen, 2022; Hopsch et al., 2009). Indeed, Atlantic hurricane season reports often cite vigorous AEWs as the initial disturbances of Atlantic TCs.…”

“…For example, out of a 23‐year average of 58 tropical waves that moved across the Atlantic during hurricane season, only 30% developed into TCs (Avila, 1991). Many studies have therefore examined the characteristics and environments of developing and non‐developing waves in an effort to understand the circumstances under which AEWs lead to tropical cyclogenesis (Asaadi et al., 2016, 2017; Bercos‐Hickey et al., 2023; Dunkerton et al., 2009; Enyew & Mekonnen, 2022; Hopsch et al., 2009; Núñez Ocasio et al., 2021; Peng et al., 2012; Ross et al., 2009; Z. Wang et al., 2012). Dunkerton et al.…”

“…In addition to examining the characteristics of developing and non‐developing AEWs, previous studies have also investigated the environmental conditions associated with the waves (Bercos‐Hickey et al., 2023; Enyew & Mekonnen, 2022; Kerns & Zipser, 2009; Leppert et al., 2013; Peng et al., 2012; Vizy & Cook, 2009). Kerns and Zipser (2009) found that the 925 hPa vorticity and the mid‐level mixing ratio were the best predictors for discriminating between developing and non‐developing disturbances in the Atlantic.…”

“…Similarly, Bercos‐Hickey et al. (2023) examined developing and non‐developing AEWs in High‐Resolution Model Intercomparison Project models (Haarsma et al., 2016) and also found that developing waves were stronger than non‐developing waves, as measured by eddy kinetic energy (EKE) and curvature vorticity (CV). Additionally, they found that environmental conditions were more favorable for tropical cyclogenesis for developing AEWs, indicating that development may be a function of both the wave and the environment.…”

The Effects of African Easterly Wave Suppression by Wave Track on Atlantic Tropical Cyclones

“…A seed disturbance is a convective weak vortex that is generated within the large‐scale circulation (Hsieh et al., 2022), which can then evolve into a TC depending on the environmental conditions (Hoogewind et al., 2020; Hsieh et al., 2020; Tang & Camargo, 2014; Vecchi et al., 2019; Yang et al., 2021). Many previous studies have examined how convection drives AEWs and how AEWs serve as seed disturbances for TCs (Avila & Pasch, 1992; Bercos‐Hickey et al., 2023; Berry & Thorncroft, 2012; Chen & Dudhia, 2001; N. L. Frank, 1970; Hopsch et al., 2007, 2009; Landsea, 1993; Núñez Ocasio & Rios‐Berrios, 2023; Russell & Aiyyer, 2020; Thorncroft & Hodges, 2001). For example, Thorncroft and Hodges (2001) found that tracked AEWs in reanalysis data were positively correlated with Atlantic TC activity between 1985 and 1998 and that TC activity was mostly associated with the south AEW track.…”