85th AMS Annual Meeting

Tuesday, 11 January 2005: 1:30 PM
Along-frontal kinematic and moisture variability and the impact on convection initiation
Tammy M. Weckwerth, NCAR, Boulder, CO; and H. V. Murphey, C. Flamant, C. R. Pettet, and R. M. Wakimoto
Poster PDF (2.0 MB)
The International H2O Project (IHOP_2002) was designed to sample the three-dimensional time-varying moisture field to better understand convective processes. Numerous research and operational water vapor measuring systems and retrievals were operated in the U.S. Southern Great Plains from 13 May to 25 June 2002. This was done in combination with more traditional observations of wind and temperature. Convection initiation (CI) missions were designed to maximize observational overlap from multiple instruments to better understand the processes leading to the development of deep, moist convection. One particularly unique tool on the CI missions was a horizontal-pointing water vapor differential absorption lidar (DIAL; Leandre II) flown with an airborne Doppler radar (ELDORA) on-board a P-3 aircraft.

Spectral analyses of numerous fields on 12 June 2002 identified internal gravity waves. The waves were interacting with two low-level boundaries (i.e., outflow boundary and dryline) prior to CI. The goal is to examine the moisture and kinematic variability associated with the waves, especially at the intersections between the waves and the boundaries. It is suspected that the waves may cause an along-boundary periodicity of moisture and vertical motion. In addition to the Leandre II, ELDORA and P-3 in situ measurements providing the moisture and kinematics along the boundaries and waves, several other mobile datasets are included in this study: a mobile radiometer; University of Wyoming King Air in situ instruments; Mobile Integrated Profiling System (MIPS); radiosondes and dropsondes. Although the ground-based sensors (i.e., S-Pol radar, mobile radars and mobile mesonets) were farther west than the CI area, they are useful for illustrating the high-resolution boundary-layer kinematics and thermodynamics. Although CI occurred east of the Homestead profiling site, several fixed lidars and profiling instruments (e.g., Scanning Raman Lidar (SRL), Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE), Goddard Lidar Observatory for Winds (GLOW), Multiple Antenna Profiler (MAPR)) may be added to the analysis, if useful. The combination of these high-temporal and -spatial resolution measurements should provide a detailed account of the interaction of various boundaries and waves and their impact on convective development.

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