Virtual Heat Flux Measurements from a Boundary-Layer Profiler-RASS Compared to Aircraft Measurements

Abstract

Measurements of the turbulent virtual heat flux in the convective atmospheric boundary layer made with a 915-MHz boundary-layer wind profiler-radio acoustic sounding system (RASS) are compared to flux measurements from a King Air aircraft. The profiler-RASS flux was calculated by a refined eddy correlation technique. The measurements were made during the Rural Oxidants in the Southern Environment II experiment in June 1992. The area over which the measurements were made is primarily pine forest, and the dominant weather conditions were hot with light winds. The profiler-RASS measurements and the aircraft measurements agree well. Even under these light wind conditions, a 2-h-average profiler-RASS measurement may be sufficiently accurate to be useful. The instrumental error is estimated to be less than the uncertainty due to sampling of the turbulence.