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. 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 network over the contiguous U.S. It currently covers the primary convective season (March through August) of 2004-2013 at 0.02° x 0.02° x 1 km resolution. Echo-top altitudes estimated from the GridRad analysis are validated by comparisons with CloudSat retrievals. 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.