Thunderstorms enhance tropospheric ozone by wrapping and shedding stratospheric air

The stratospheric contribution has been estimated mainly using global models that attribute the transport process largely to the global-scale Brewer-Dobson circulation and synoptic-scale dynamics associated with upper tropospheric jet streams. We report observations from research aircraft that reveal additional transport of ozone-rich stratospheric air downward into the upper troposphere by a leading-line-trailing-stratiform mesoscale convective system with convection overshooting the tropopause altitude.

The fine-scale transport demonstrated by these observations poses a significant challenge to global models that currently do not resolve storm-scale dynamics. Thus, the upper tropospheric ozone budget simulated by global chemistry-climate models where large-scale dynamics and photochemical production from lightning-produced NO are the controlling factors may require modification.