Cloudwater sampling campaign at Hoher Sonnblick

From March 16-18 a proven measuring and collecting method was brought back to life at the Sonnblick Observatory (SBO). For cloud in situ monitoring within the framework of ACTRIS (European research infrastructure for aerosols, clouds and trace gases,, a test run for cloud water sampling was carried out as part of the internal project "ASBO". Dr. Anne Kasper-Giebl, professor at the TU Vienna, carried out a new series of experiments to determine the water content in clouds, supported by four students. The campaign was accompanied by Christian Maier, the ACTRIS operator at the SBO. A sample (Fig. 1) was taken from the Cloud Water Sampler (CWS) every 1.5 hours (Fig. 2).

Abb. 1. Samplecylinder CWS © TU Wien, Karoline Rieger


Abb. 2: Cloud water sampler © TU Wien, Bernadette Kirchsteiger

The sample obtained is then analyzed for ingredients in the laboratory, and the liquid water content in the cloud can be determined. The CWS was developed as part of the "ALPTRAC" project for a harsh environment with high wind speeds and is now back in use. The large shield automatically turns into the wind and reduces the wind speed above the collection opening. Cloud droplets can be sucked into the impactor by a constant flow of air and deposited there. Subsequently, the supercooled droplets freeze inside the cylinder.

The measurement campaign could be carried out healthily by adhering to all COVID measures.