End of wintertime deployment of LACROS to Switzerland

By the beginning of March 2024, the mobile exploratory platform LACROS of TROPOS was returned from the third of a series of winter campaigns near Eriswil in the centre of Switzerland. LACROS joint the 3‐months campaign, which was conducted under the umbrella of the ERC research project CLOUDLAB of ETH Zurich, in the framework of the PolarCAP (Polarimetric Radar Signatures of Ice Formation Pathways from Controlled Aerosol Perturbations) project.

The CLOUDLAB campaign jointly brought together a unique set of ground‐based and airborne in‐situ cloud and precipitation sensors and remote sensing instruments. Given the scanning 35‐GHz and vertical‐pointing 94GHz cloud radars of the LACROS instrument suite, the 35‐GHz scanning cloud radar of ETH Zurich, and additional instrumentation provided by University of Leipzig (scanning 94GHz cloud radar) and EPFL (scanning X‐band radar), the campaign was one of the largest joint deployments of multi‐wavelength radar but also lidar systems. The campaign gives a unique chance to validate remote sensing retrievals of mixed‐phase cloud microphysics against in situ observations. In addition, the evolution of cloud systems under slightly supercooled conditions down to ‐10°C can be studied in great detail given the vast set of instruments.

An overview of the campaign can be seen in the photo above. Photo credit: Jan Henneberger