Center for Cloud Water Chemistry (CCWaC)

The Center for Cloud Water Chemistry (CCWaC) is operated by the Atmospheric Chemistry Department (ACD) as a unit of the Cloud-in-situ Topical Center within the framework of ACTRiS (Aerosols, Clouds and Trace gases Research Infrastructure). As a calibration center, CCWaC is responsible for the quality assurance of sampling and chemical analyses of cloud water.

A range of analytical instruments are used in several laboratories to develop and implement methods for investigating the chemical composition of cloud water samples. These include ion chromatographs for the determination of inorganic ions and short-chain carboxylic acids and total carbon analyzers for water-soluble organic carbon. In addition, CCWaC conducts regular field campaigns to test the comparability of different cloud water samplers.  Field experiments will primarily be performed at the Schmücke Cloud Observatory (SCO).


Figure 1: a) Cloud water collectors during a comparison campaign. b) Laboratory building of the Atmospheric Chemistry Department. c) Measurement-tower on Mt. Schmücke for field campaigns. d) Total carbon analyzer. E) Ion chromatograph for the determination of carboxylic acids.

The results of this laboratory and field work will feed into the development of data quality objectives, technical requirements and measurement guidelines during the implementation phase to ensure comparability between multiple observatories within ACTRIS. After full implementation in 2026, CCWaC will continue to organize regular comparison campaigns, interlaboratory campaigns and quality assurance workshops during the multi-year operational phase of ACTRIS and provide operational support for cloud water chemical analysis.

Further information can be found here: