The Dynamical Relationship between Subtropical and Eddy-Driven Jets

This study examines the impact of a subtropical jet on the development of baroclinic waves and polar-front jets with an idealized multilevel primitive equation model. Linear stability analysis and initial-value approaches suggest that baroclinic wave growth is most favored along the subtropical jet only when this jet is sufficiently strong. For a subtropical jet of modest strength, the most favorable region for baroclinic wave growth often lies 20° to 30° poleward of the subtropical jet, establishing an eddy-driven jet that is latitudinally well separated from the subtropical jet.