Behaviour of an ultrasonic anemometer under cloudy conditions

The use of ultrasonic anemometers under cloudy weather conditions is often doubted, even rejected or not discussed in the literature. To investigate t he influence of liquid water content on the behaviour of sonic anemometers a small intercomparison experiment using an ultrasonic anemometer, a fast r esponse propeller anemometer, and a Particulate Volume Monitor was performe d at the German Environmental Research Station `Schneefernerhaus' near the top of Mt. Zugspitze. The results obtained under different conditions (dry/ cloudy) give no significant hint on such an influence.