Combined Wind Profiler/Polarimetric Radar Studies of the Vertical Motion and Microphysical Characteristics of Convection: Darwin and Oklahoma Observations

Wind profilers offer the unique ability to directly measure vertical motion profiles through precipitating and non-precipitating cloud systems. This ability has been exploited through a series of analyses of storms near Darwin, Northern Australia, which have focused on the statistical characteristics of the vertical motion within a large number of storms as well as case studies of squall lines and isolated convection. The statistical study of May and Rajopadhyaya (1999) looked at the intensity, size, and mass flux characteristics of a sample of twenty-nine, mostly continental storms (the monsoon was particularly weak for the year that continuous vertical motion data was available). These results were compared with aircraft studies. These showed that the intensity of the vertical motion was quite consistent with a number of tropical aircraft studies and much less than the continental convection sampled during the thunderstorm project. The size of the convective cores seen in Darwin during continental convection was somewhat larger than the oceanic cases and similar to the thunderstorm project indicating the importance of boundary-layer depth. Following these analyses, a request was made to obtain similar data from the Southern Great Plains (SGP) site to further investigate the differences in the two regimes. Observations were taken in 1999 and 2000. At present, there is insufficient data for statistical analysis, partly due to equipment reliability and partly because the probability of having storms directly over a small site, is less in Oklahoma than in Darwin. This paper will briefly describe some recent Darwin observations, discuss the Oklahoma data, and draw some conclusions on the utility of these types of analyses for Atmospheric Radiation Measurement (ARM) Program science goals.