Convective influence of clouds on redistribution of tropospheric ozone and its relationship to upper-altitude ozone enhancement above Southeastern North America

An upper-tropospheric ozone enhancement above Huntsville, AL during summertime appears to be a permanent feature as suggested by weekly ozonesonde measurements. Summertime ozone at 6-11 km altitudes above Huntsville is ~10 ppb higher on average than both the ozone at lower altitudes and the 6-11 km ozone observed at Boulder, CO. Previous studies suggest this enhancement may be associated with more frequent convection and the persistent anticyclone over Southern North America. To understand the role of convection on ozone redistribution, we employ ozonesonde data to statistically examine the relationship between ozone and cloud structure. Analyzing the frequency of occurrence of convective clouds, quantifying the ozone in cloud inflow and outflow regions, and comparing the results in different locations contribute to our understanding. The UAHuntsville ozone lidar measurements also contribute to case studies investigating the high-temporal ozone evolution associated with cloud scavenging effects and quantify ozone in the cloud inflow region. We modify a previous method to determine the cloud boundaries and validate this method with a collocated CT-25K ceilometer. This study uses simultaneous profiling of ozone and multiple meteorological parameters to improve our understanding of how cloud photochemical processes affect ozone variation.