Analysis of the evolution of an urban boundary layer ad detected by a frequency modulated-continuous wave radar

Frequency modulated-continuous wave (FM/CW) radars have been used for a number of years to investigate the evolution of the boundary layer. Typically the radars were positioned in rural environments as part of larger experiments. During the summer of 2003, the West Desert Test Center deployed a 2.9 GHz FM/CW radar just north of the central business district of Oklahoma City, OK in support of the Joint Urban 2003 urban dispersion experiment. Our primary objective was to observe the normal diurnal cycle of the boundary layer, but we also discovered several unusual aspects of the urban convective boundary layer that made assigning a single boundary layer height difficult. On several occasions we observed signatures that resembled convective folds that showed a clear overturning of the boundary layer. In other examples, we saw situations where the boundary layer, as indicated by the received backscatter power, essentially disappeared due to mixing.