ECCINT Measurement campaign summer 2024

In summer 2024, an international measurement campaign took place as part of the European Center for Cloud Intercomparison Studies (ECCINT). In addition to the focus on the basic cloud physics parameters - in particular liquid water content, effective radius and droplet spectrum - the campaign was expanded to include vertical aerosol measurements. The Sonnblick operating cable car was equipped with scientific instrumentation to record both the aerosol concentration at different altitudes and the droplet structure at the cloud base.

Around 100 measurement runs provided data on particle concentration, size distribution and droplet spectra. Thanks to collaborations with the Finnish Meteorological Institute (FMI) and ETH Zurich, these measurements were carried out in high quality. New insights into interactions between aerosols and clouds were gained, particularly during stationary flights under cloudy conditions - an important contribution to improving climate models.

At the same time, the evaluation of the measurement data revealed some considerable differences between the instruments used - for example, deviations of up to a factor of 2 in the liquid water content. These discrepancies can be attributed to meteorological influences (e.g. icing, wind direction) and instrument-specific weaknesses. As a consequence, the further development and standardization of the measuring instruments - also in the context of ACTRIS and ECCINT - is to be intensified.

The next international campaign is already planned for spring/summer 2026, with a focus on the combination of in-situ measurements and remote sensing to enable a more comprehensive recording of cloud processes.