Investigation of turbulent processes in the lower troposphere with water vapor DIAL and radar-RASS

High-resolution water vapor and wind measurements in the lower troposphere within the scope of the Baltic Sea Experiment (BALTEX) are presented. The m easurements were performed during a held campaign with a new water vapor di fferential absorption lidar (DIAL) system and a radar-radio acoustic soundi ng system (radar-RASS). The analysis of a continuous 24-h measurement perio d shows that the resolution and the accuracy of these instruments are capab le of measuring profiles of water vapor and vertical wind fluctuation momen ts up to the second order to investigate turbulent processes in the convect ive boundary layer. Besides the high-resolution data obtained with each ins trument it is their combination that yields a further: important variable i n the boundary layer: the turbulent latent heat Aux measured directly using the eddy correlation method. The results demonstrate that active remote se nsing instruments like DIAL and radar-RASS can be routinely applied to prov ide previously unavailable datasets for detailed investigations of turbulen t processes. Thus, the instruments can contribute significantly to one of t he major goals of regional continental-scale experiments like BALTEX: the i nvestigation of models and the improvement of their parameterization of sma ll-scale processes.