Presentation Title:Insights from Glaciogenic Seeding Of Low Stratus Clouds with a UAV
Full Name:Jan Henneberger
Affiliation / Institution:ETH Zurich, Zurich, Switzerland
Co-Author
Full Name:Christopher Fuchs
Affiliation / Institution:ETH Zurich, Zurich, Switzerland
Co-Author 2
Full Name:Anna Miller
Affiliation / Institution:ETH Zurich, Zurich, Switzerland
Co-Author 3
Full Name:Kevin Ohneiser
Affiliation / Institution:Leibniz Institute for Tropospheric Research (TROPOS), Leipzig, Germany
Co-Author 4
Full Name:Nadja Omanovic
Affiliation / Institution:ETH Zurich, Zurich, Switzerland
Co-Author 5
Full Name:Fabiola Ramelli
Affiliation / Institution:ETH Zurich, Zurich, Switzerland
Co-Author 6
Full Name:Patric Seifert
Affiliation / Institution:Leibniz Institute for Tropospheric Research (TROPOS), Leipzig, Germany
Co-Author 7
Full Name:Robert Spirig
Affiliation / Institution:ETH Zurich, Zurich, Switzerland
Co-Author 8
Full Name:Huiying Zhang
Affiliation / Institution:ETH Zurich, Zurich, Switzerland
Co-Author 9
Full Name:Ulrike Lohmann
Affiliation / Institution:ETH Zurich, Zurich, Switzerland
Abstract:In the context of anthropogenic climate change, there has been a renewed interest in glaciogenic cloud seeding as a potential method for precipitation enhancement, hail prevention, or fog dissipation. This technique typically involves introducing significant amounts of silver iodide into clouds, yet its overall efficacy remains a contentious topic, primarily due to challenges in assessing the evolution of unseeded clouds and the lack of systematic, in-situ observations of cloud microphysical changes immediately after seeding. The CLOUDLAB project targets supercooled low stratus clouds, which typically do not produce substantial precipitation. However, their persistent nature and absence of pre-existing ice crystals offer an ideal environment for seeding experiments. Utilizing an Uncrewed Aerial Vehicle (UAV) for seeding allowed an accurate control over the seeding location. Changes induced by seeding are monitored 5-15 minutes downstream using multiple scanning and vertically-pointing cloud radars, alongside a tethered balloon system equipped with aerosol spectrometry and holographic imaging, offering phase-resolved size distributions of cloud droplets. Over 70 seeding experiments were conducted over the Swiss Plateau, covering temperatures from -10°C to -3°C. The controlled and systematic approach of CLOUDLAB showcasing its potential to enhance understanding of microphysical processes critical for refining weather modification strategies and optimizing their efficacy.