Diabatically Induced Secondary Flows in Tropical Cyclones. Part I: Quasi-Steady Forcing

• DOI: 10.1175/2008mwr2657.1
• Publication Date: 2008-09-19T21:38:15Z
• Authors: Angeline G. Pende...; Hugh E. Willoughby
• Keywords: Stream function; Eye; Forcing (mathematics); Circulation (fluid dynamics); Secondary circulation

Abstract The Sawyer–Eliassen Equation (SEQ) is here rederived in height coordinates such that the sea surface also a coordinate surface. Compared with conventional derivation mass field coordinates, this formulation adds some complexity, but arguably less than inherent terrain-following or interpolation to lower physical boundary. Spatial variations of static stability change vertical structure flow streamfunction. This effect leads significant changes both secondary-circulation and intensification primary circulation. SEQ solved on piecewise continuous, balanced mean vortex where shapes wind profiles inside outside eye tilt specified heat source can be adjusted independently. A series sensitivity studies shows efficiency which imposed heating intensifies most sensitive intensity itself as measured by maximum size radius wind. Vortex shape forcing have impacts 20%–25% great size, suggesting aspects tropical cyclones predispose them rapid are environmental thermodynamic rather kinematic.