Pilot high altitude cloud ambient measurement performance study

The European Centre for Cloud Ambient Intercomparison (ECCINT) unit of the Centre for Cloud In-Situ Measurements (CIS) collaborated with Palas GmbH for a pilot high altitude cloud ambient measurement performance study.

The study was performed in 2022 at Sonnblick Observatory where 24 dedicated instruments were used to determine a wide range of cloud parameters, such as the liquid water content, the size and composition of the droplets and ice crystals, and the chemical composition of the cloud water. Figure 11: Left: Sonnblick Observatory; right: measurement platform at Sonnblick Observatory. Among them, there was the Cloud Droplet Analyzer from Palas GmbH. The precise aerosol spectrometer measures the size of dust particles and, under appropriate conditions, also fog droplets and determines the water content of the air. It also measures the distribution of Saharan dust, which is transported from the desert across the Alps to Central Europe. At the same location, a condensation particle counter (ENVI-CPC) for measuring ultrafine particles and a scattered-light aerosol spectrometer (promo® 3000) have been used for years. The results of this study are made available to the scientific community through the Global Atmosphere Watch (GAW) programme for the evaluation of climate studies worldwide.