Transport and Diffusion in the Transition Layer and Planetary Boundary Layer for Drainage Flows in Anderson and Putah Creeks, California, during ASCOT 1980

Abstract

Abstract Approximately 100 constant-volume, superpressured balloons (tetroons) were tracked in the Anderson and Putah Creek drainages of the Geysers geothermal area of northern California as part of the ASCOT (Atmospheric Studies in Complex Terrain) program. These tetroons were tracked by radar. Each tetroon was equipped with a transponder which provided a 100 MHz shift in frequency, providing a means of discriminating the tetroon-transponder broadcast signal from radar signals reflected from the hard terrain. Tetroons were used to provide direct measurements of trajectories of individual air parcels, to provide transport speeds of individual air parcels and to provide direct measurements of the turbulence associated with an individual parcel of air. In addition, clusters of tetroons were released, providing direct measurement of the very low frequency turbulence associated with air flow meander within the two valleys. All tetroon flights were in the transition layer between the katabatic drainage flow an...