Multi-sensor analysis of the 18 June 2002 retrograding dryline and convective initiation in Kansas during IHOP.

摘要

This study examines a retrograding dryline which occurred in Kansas during the International H2O Project (IHOP_2002). This event is unique in that convective initiation (CI) occurred west of the dryline, where limited moisture exists. The boundary layer (BL) change with dryline passage, the dryline's structure, and possible mechanisms for CI are presented using extensive observations from the Mobile Integrated Profiling System (MIPS), aircraft, mobile soundings, and mobile Doppler Radars. Observations from the MIPS, soundings, and aircraft depict the changes in BL quantities across the dryline, and are used along with detailed Dual-Doppler wind syntheses, which address the dryline's structure and CI mechanisms. It is proposed that the dryline initially was not behaving as a density current, but became similar to one as it passed under a thunderstorm anvil shadow. In addition, a possible CI mechanism is presented and supported by MIPS measurements and results from an MM5 simulation.