Synoptic Environments and Characteristics of Convection Reaching the Tropopause over Northeast China

Abstract

AbstractOvershooting convection that penetrates the lapse rate tropopause is defined globally using 3 years of Global Precipitation Measurement (GPM) observations and ERA-Interim data. Overshooting convection in the subtropics is mainly found over a few hot spot regions, including central North America and Argentina. A relatively high density of events with overshooting convection is also found over northeast China in the summer months, where 203 events are identified during 2014–16. These convective events extending above the tropopause occur under various synoptic conditions. The synoptic conditions during these events are categorized into three different types, namely, trough, cutoff low, and ridge types, with a subjective analysis based on the wind and pressure fields at 500 hPa. The precipitation systems with overshooting convection ahead of a deep trough have larger sizes than other types. Those in the cutoff low environment are mostly embedded within a large precipitation system. The ridge-type systems have a stable midtroposphere and a high moist instability at low levels and are mostly isolated convective systems, characterized by smaller sizes, higher radar echo top, and larger convective area and precipitation fraction than the other two types.