EOL seminar presented by Dr. Tammy Weckwerth, Remote Sensing Facility (RSF) of EOL
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 systems for measuring water vapor, via in situ and remote techniques, 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 study the processes leading to the development of deep, moist convection. This case study examines the interactions between several clear-air features, as well as their impact on the distribution of water vapor, which led to convection initiation on 12 June 2002. The supercells that developed produced damaging winds and hail. The clear-air, pre-convective features included i) a dryline, ii) an old outflow boundary/warm front, iii) their intersection, iv) a mesolow, v) internal gravity waves and vi) horizontal convective rolls.
Many unique instruments were positioned to sample the pre-convective environment on 12 June 2002. Ground-based research and operational radars, including S-Pol, sampled the overall clear-air and convective structure. The airborne Leandre II water vapor DIAL, ELDORA airborne Doppler radar, P-3 in situ sensors, surface-based wind profilers and extensive surface station measurements provided information on the moisture and vertical velocity distribution within the boundary layer. Radiosondes and dropsondes were used to obtain profiling information throughout the atmosphere. The combination of these high-temporal and -spatial resolution measurements provide a detailed account of interactions between the various boundaries, mesolow, waves and rolls and their impact upon convective development. WRF 4-km simulations were performed to address the generality of the observational results. The simulations thus far show reasonable results but with a strong sensitivity to initial conditions. Conclusions about the scales of observed features that are important for influencing the timing and location of new convection on 12 June 2002 will be presented.
Wednesday, April 5 at 3:30pm in FL2-1022.
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