The pan-European research infrastructure ACTRIS (The Aerosol, Clouds and Trace Gases Research Infrastructure) is aiming to produce high-quality data and information on short-lived atmospheric constituents and on the processes leading to the variability of these constituents in natural and controlled atmospheres. (https://www.actris.eu)

As part of ACTRIS the Karlsruhe Low Cloud Exploratory Platform (KLOCX) serves as a fully mobile ground-based observation system. It is mainly aimed to investigate processes involved in the development and dissipation of low-level clouds and fog using in-situ and remote sensing instruments.

Low-level clouds and fog impact our climate system but also human life. They reflect sunlight back into space, but also trap the Earth's thermal radiation. Up until now, one of the big questions in climate research is how strong these effects actually are. For humans, low-level clouds mostly pose a severe threat for aviation, sea and road traffic due to reduced visibility and they can prolong weather conditions favorable for reduced air quality.

With KLOCX, it will be possible to efficiently bundle the instrumentation needed for process studies directed to understand low-cloud and fog formation, persistence, and dissipation. Besides providing data for such process studies, the data collected will be available as ground truth to further improve satellite-based detection schemes of low clouds and fog.