Thursday, 26 January 2012
Tropical Energy Bubbles and the Subtropical Jet Stream
Hall E (New Orleans Convention Center )
Krishnamurti (1961a,b) was one of the first to discuss the relationship between tropical circulations and the subtropical jet stream and its interaction with baroclinic flows of the middle latitudes. There, he showed how the jet was maintained by fluxes of angular momentum and kinetic energy, fueled by latent heat energy drawn from the ocean surface. This work helped motivate recent investigations by Mecikalski and Tripoli (1998), Rappin, Morgan and Tripoli (2011), and Tripoli (2011) which have further explored the dynamics of how tropical convection and tropical cyclones directly force jet stream evolution and how jet stream evolution in turn impact tropical convection and tropical storms. Extending the zonally averaged relationships of Krishnamurti, Tripoli (2011) has pointed to discrete “energy bubbles” formed by individual tropical events that drive the formation of individual jet streaks. These jets take the form of subtropical jet streaks when formed at the poleward limit of upper level transport, defined by angular momentum constraints, or “super jet streaks” that are formed when the “energy bubble” interacts directly with the polar tropopause. A discussion of these recent findings in the context of Krishnamurti's original work will be presented at the oral presentation.
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