AOPP Seminar: Jets, storm tracks and diabatic processes

In this talk, I will present findings related to the role of diabatic processes in atmospheric dynamics, with a focus on the jet stream and storm tracks. First, I will discuss how these processes influence jet stream intensity from the perspective of Lagrangian potential-vorticity gradient tendencies. The Lagrangian PV gradient framework is an effective means of studying adiabatic–diabatic interactions in atmospheric dynamics. Climatological analysis reveals that moist processes strengthen the jet stream on the equatorward side of its entrance region, while radiation strengthens it along its axis, and turbulence acts on the poleward side of the jet exit region. Secondly, the jet stream is known to exhibit a symbiotic relationship with surface extratropical cyclones, and moist processes are known to intensify baroclinic growth. The cyclone intensity is shown to be inherently connected to the poleward propagation of these systems, with moist diabatic processes amplifying this process. This process is too weak in climate models partly causing storm tracks to be too zonal. Finally, I discuss the inverse relationship between the intensity of extratropical cyclones and the jet strength on synoptic scales, and how the seasonal cycle can mask this, suggesting a positive relationship.