Tropopause-Overshooting Convection from GridRad Radar Observations

Deep convection that crosses the tropopause can have a substantial impact on the composition, radiation, and chemistry of the upper troposphere and lower stratosphere and has been linked with the occurrence of severe weather at Earth’s surface. We present a 10-year analysis of tropopause-overshooting convection for the contiguous United States using GridRad radar data. GridRad is an hourly, high-resolution, three-dimensional, gridded, radar reflectivity analysis created by merging observations from all available radars in the NEXRAD WSR-88D network over the contiguous U.S. It currently covers the years 2004-2013 at 0.02° x 0.02° x 1 km longitude-latitude-altitude resolution. Echo-top altitudes estimated from the GridRad analysis are validated by comparisons with CloudSat Cloud Profiling Radar observations. Overshooting convection is identified by radar echoes located above the ERA-Interim reanalysis lapse-rate tropopause. We discuss the frequency; diurnal, seasonal, and interannual variability; vertical extent; and geographic distribution of overshooting convection.