Cyclone-anticyclone asymmetry concerning the height of the thermal and thedynamical tropopause

The differences between upper-tropospheric cyclones and anticyclones are in vestigated regarding the height of the thermal and the dynamical tropopause . The problem is addressed in an idealized framework by analyzing axisymmet ric balanced flows, which are characterized by a radial scale DeltaR and a tropopause potential temperature anomaly Delta theta, where cyclones and an ticyclones differ only by the sign of Delta theta. The height of the therma l tropopause significantly differs from the height of the dynamical tropopa use unless the anomaly is shallow. There is a pronounced asymmetry in that the differences are much larger and more likely to occur in the case of cyc lones. Two factors contribute to this asymmetry. First, for a given amplitu de \Delta theta\, cyclones and anticyclones have different aspect ratios in geometric space; second, for a high-latitude winter scenario the critical lapse rate of the WMO thermal tropopause is asymmetric with respect to typi cal tropospheric and stratospheric lapse rates. Simulated station statistic s regarding the height of the two tropopauses share essential qualitative f eatures with similar statistics from observations. The asymmetry in the mod el sensitively depends on the lower-stratospheric lapse rate. Multiple trop opauses may greatly enhance the asymmetry.