Open AccessThe Resonant Interaction of a Tropical Cyclone and a Tropopause Front in a Barotropic Model. Part I: Zonally Oriented Front
Author(s) -
Leonhard Scheck,
Sarah Jones,
Martin Juckes
Publication year - 2011
Publication title -
journal of the atmospheric sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.853
H-Index - 173
eISSN - 1520-0469
pISSN - 0022-4928
DOI - 10.1175/2010jas3482.1
Subject(s) - barotropic fluid , cyclone (programming language) , tropopause , front (military) , baroclinity , geology , potential vorticity , vorticity , vortex , meteorology , climatology , physics , mechanics , extratropical cyclone , tropical wave , atmospheric sciences , tropical cyclone , troposphere , field programmable gate array , computer science , computer hardware
The interaction of a tropical cyclone and a zonally aligned tropopause front is investigated in an idealized framework. A nondivergent barotropic model is used in which the front is represented by a vorticity step, giving a jetlike velocity profile. The excitation of frontal waves by a cyclone located south of the front and the impact of the wave flow on the cyclone motion is studied for different representations of the cyclone and the jet. The evolution from the initial wave excitation until after the cyclone has crossed the front is discussed. The interaction becomes stronger with increasing jet speed. For cyclone representations containing negative relative vorticity, anticyclones develop and can influence the excitation of frontal waves significantly. Resonant frontal waves propagating with a phase speed matching the zonal translation speed of the cyclone are decisive for the interaction. The frontal wave spectrum excited by a cyclone on the front is dominated by waves that are in resonance in the initial phase. These waves have the largest impact on the cyclone motion.