Ciclones em Superfície nas Latitudes Austrais. Parte III: Energética

Abstract This study presents the energy analysis of four cyclone cases in southern latitudes, being two extratropical (one Bjerknes and Solberg type and the other Shapiro and Keyser type), a tropical and a subtropical, in order to complement the work “Surface Cyclones over Austral Latitudes: Part II Cases Study”. We applied the eddy kinetic energy equation developed by Orlanski and Katzfey, because it contemplates the main mechanisms for the formation and dissipation of the transient systems, namely baroclinic and barotropic instabilities and downstream development. The energy analysis shows that the baroclinic conversion term was the most important during the life cycle of the four studied cyclones, whereas the barotropic term was small. On the other hand, the downstream development term, known also as ageostrophic flow convergence, had negative contribution for all cases, exporting kinetic energy out of the cyclone region.