Determination of turbulent parameters in the atmospheric boundary layer with an UHF wind profiler. Comparison with in situ measurements

Abstract

(Août 2004)This study presents methods to determine turbulent parameters in the ABL with UHF wind profilers. These methods are compared with aircraft data measured during TRAC-98 campaign. The results of this comparison show that : (i) the turbulent kinetic energy dissipation rate measured by both instruments are well correlated with a slightly overestimation and underestimation of the UHF radar below and above 0.7Zi respectively ; (ii) the momentum fluxes measured by the UHF profiler is the same order of magnitude than the aircraft ones but is globally underestimated in the ABL, which can be the consequence of the larger turbulent scales not took into account by this instrument (keeping out the levels inferior to 0.3Zi where ground echoes perturb UHF profiler measurements) ; (iii) the sensible heat fluxes measured by both instruments are well correlated with a slightly overestimation of the UHF radar mainly caused by the overestimation of the dissipation rate and losses of mechanical production below and above 0.7Zi respectively