Stratosphere‐troposphere exchange ozone flux related to deep convection

We study the mechanisms driving stratosphere‐ troposphere exchange of ozone fluxes within a chemistry‐ transport model. For years 2004–2006, year‐round, most of the stratosphere‐to‐troposphere flux of O 3 is associated with shear and folding around the subtropical jet, and this jet‐related flux peaks for the northern hemisphere in May. Over the northern mid‐latitude continents, however, surface convection penetrates to stratospheric levels of O3 (250 ppb), enhancing the O3 flux by 19% of the northern hemisphere total, and shifting the peak flux to June. This convection‐ related O3 flux represents 49% of the total over northern mid‐latitudes in June.