Measurements of turbulent heat and momentum fluxes in a mountain valley

Abstract

Measurements of heat and momentum fluxes along the valley floor of Brush Creek in Colorado are described. The measurements were taken in the fall of 1984 as part of the Department of Energy's Atmospheric Studies in Complex Terrain field program. The sensible heat flux to the ground descreased from approximately 40-60 W m-2 prior to midnight to about 10-25 W m-2 in the morning hours. Surface friction velocities u* ranged from approximately 20-15 cm s-1 during the corresponding time periods. Considerable site-to-site variability in flux values was found, and disturbances of the upwind flow appear to be a significant contributing cause. -Authors