This study investigates the impact of local convergence and divergence of air on turbulent transfer at a mid-latitude alpine fellfield site. Pairs of simultaneous wind and temperature profile measurements on a knoll crest and primary slope (aspect =0, 90, 180, and 270°) are analyzed assuming the logarithmic law. Friction velocity (u) and roughness length (z0) vary systematically from windward to leeward slopes. General relationships of the form u = f(u) are derived for conditions of westerly flow with wind speed (u) ranging between 2 and 24 m s-1. Coefficients in the empirical equations for estimating u at sites on the knoll from wind speed measurements on the crest vary in a consistent manner with respect to local convergence and divergence. Large differences in z0 values between windward and leeward sites correspond with contrasts in surface temperature.
All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
- Earth and Planetary Sciences(all)