Heat and Momentum Flux Measurements in the Planetary Boundary Layer with a Wind Profiling Radar/Radio Acoustic Sounding System

摘要

The planetary or atmospheric boundary layer structure and dynamics are key to understanding, modeling, and predicting climate, weather, and pollution. New and improved techniques for measuring the dynamics of the boundary layer are needed. One of the most important needs is for improved methods of measuring the turbulent fluxes of heat and momentum. Existing methods involving towers, surface measurements, or aircraft have limited flexibility or are expensive. This memorandum describes methods for measuring heat flux (virtual temperature flux) and momentum flux in convective boundary layers. The instrument used is the 915 MHz boundary-layer radar wind profiler radio acoustic sounding system (profiler/RASS). As the name suggests, the profiler was developed to make wind measurements, and this work is an expansion of its capabilities. The radio acoustic sounding system uses the profiler and attachments to measure virtual temperature. Results of studies indicate that the profiler/RASS is capable of making heat flux measurements that compare well with aircraft and surface measurements.