EVIDENCE OF ORGANIZED LARGE EDDIES BY GROUND-BASED DOPPLER LIDAR, SONIC ANEMOMETER AND SODAR

In an experiment investigating the planetary boundary layer (PBL) wind and temperature fields, and PBL inversion height recorded by various instruments, the results reveal the presence of organized large eddies (OLE) or rolls. The measurements by lidars, anemometers, soundings an d sodar gave an overview of the characteristics of the rolls and sourc es of energy production that maintain them. The experimental results o btained on two consecutive days are compared to model outputs. The agr eement is excellent, showing that thermal stratification and wind shea r are important factors in the structure and dynamics of OLE. A hetero dyne Doppler lidar (HDL) is shown to be a useful tool in the study of OLE.