PV Frontogenesis and Upper-Tropospheric Fronts

Upper-tropospheric fronts and frontogenesis are viewed from a potental vorticity (PV) perspective. The rudiments of this approach are to regard such a front as a zone of strong PV gradient on isentropic surfaces, and to treat the accompanying frontogenesis as the process whereby this gradient is enhanced on tropopause-transcending isentropic surfaces. A case study suggests that this concept of PV frontogenesis provides a concise dynamically based definition of upper-level frontal zones, and a compact and transparent approach for diagnosing the frontogenesis. The concept provides fresh insight on the dynamics of the upper-level fronts, and has the potential to shed light on related phenomena and processes.