Relationship between stratospheric tracers and surface ozone at a mid-latitude site

Stratospheric ozone influences the composition of the free troposphere through Stratosphere-Troposphere Exchange (STE). Tropopause folds are a fairly common STE phenomena in extratropical regions contribute that potentially contribute to surface ozone. However, the magnitude of STE contribution to surface ozone is poorly quantified. In the Spring of 2012 7Be , ozonesonde and relative humidty profiles, and speciated Hg measurements, were used to identify stratospherically impacted air masses. Several frontal passages were analyzed using both the SUNY-Albany Global Forecast System (GFS) model of potential vorticity and tropopause height and the NOAA Air Resources Laboratory (ARL) Hysplit trajectory model. This analysis will be used estimate the amount of ozone brought down to the surface in Houston Texas through springtime STE events.