Thermal versus dynamical tropopause in upper-tropospheric balanced flow anomalies

This paper systematically investigates differences between the thermal and the dynamical tropopause for upper-tropospheric balanced flow anomalies. Id ealized cyclonic and anticyclonic anomalies are considered, which are eithe r axisymmetric or plane symmetric. Given a distribution of potential vortic ity (PV), the inversion problem is solved numerically to obtain the corresp onding balanced flow (i.e. wind and temperature). The control parameter is the aspect ratio of the PV anomaly, which governs the partitioning into a t hermal and a dynamical anomaly. For PV anomalies of intermediate and tall a spect ratios, the location of the thermal tropopause differs significantly from the location of the dynamical tropopause. The thermal tropopause is ra ther indistinct for intermediate aspect ratios, while it is sharp and well defined for both tall and shallow anomalies. A barotropic deformation flow field superimposed on a plane symmetric anomaly induces an ageostrophic win d which modifies the static stability throughout the PV anomaly such that t he thermal and dynamical tropopauses evolve differently. Recent observation s concerning the correlation between the thermal and ozone tropopauses can be interpreted consistently in terms of the present results.