JP7.6
Cloud model based interpretation of satellite observed IR features of enhanced-V and cold ring on top of severe thunderstorms
Pao K. Wang, Univ. of Wisconsin, Madison, WI; and M. Setvak, R. Rabin, and A. S. Bachmeier
Satellite observations of severe thunderstorms reveal many intriguing features such as the enhanced-V, warm-cold couplet, distant warm area, cold ring and various complex wave structures at the storm top in both visible and infrared bands. Understanding the physical mechanisms responsible for these features not only is of fundamental importance in atmospheric science but helps the detection, monitoring and nowcasting of severe storms and to alleviate storm damages. In this study, we use cloud model simulation of a typical US High Plains severe storm to investigate the mechanisms responsible for the enhanced-V (or cold-V) and cold-ring features observed in satellite infrared images of severe storms. Analysis of model results shows that the enhanced-V and associated features (such as the warm-cold couplet) are mainly produced by the dynamic interaction between the upper level ambient winds and the strong updraft of the deep convection which behaves almost as an obstacle in the ambient flow. When the ambient winds are removed from the initial sounding in the simulation, the cold ring feature appears, suggesting that the observed cold ring is likely to be produced by the relative weak upper level wind shear. Animation videos of the simulated storm that reveal both features will be shown to illustrate these interpretations.
Joint Poster Session 7, Natural Hazards
Wednesday, 14 January 2009, 2:30 PM-4:00 PM, Hall 5
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