REMOTE-SENSING OF VERTICAL VELOCITY VARIANCE AND SURFACE HEAT-FLUX INA CONVECTIVE BOUNDARY-LAYER

The vertical velocity variance in the convective atmospheric boundary layer is estimated from measurements made with a 915-MHz boundary laye r wind-profiling radar. The vertical velocity variance estimates are u sed to infer the surface virtual heat flux through a relationship with the convective velocity scale w. The flux estimates are compared wit h in situ surface flux measurements and estimates extrapolated to the surface from direct eddy correlation measurements made with a profiler and radio acoustic sounding system. The measurements were made during the Rural Oxidants in the Southern Environment II Experiment in June 1992. The experiment area is primarily pine forest, and the dominant w eather conditions were hot with light winds. The profiler variance mea surements are compatible with theory and earlier observations. Both re mote radar methods of estimating surface virtual heat flux agree with in situ measurements to within the sampling uncertainty.