Glaciogenic Seeding on Mixed-Phase Clouds for Radiation Management (GLANCE)

This project will use a climate model in different configurations to simulate mixed-phase cloud thinning, a new climate intervention proposal based on seeding supercooled liquid clouds in winter with ice-nucleating particles. This causes the cloud to glaciate and converts a non-precipitating cloud into a precipitating one. Since these clouds warm the Earth’s atmosphere system in polar winters, dissolving them allows more longwave radiation to be emitted to space and will cause a cooling of the climate system in polar regions. This proposal could thus help to restore sea ice and offset some of the expected warming over the polar oceans due to climate change. Its main advantages are a more localized, short-term effect and easier deployment compared to other proposals such as stratospheric aerosol injections, resulting in a lower risk of long-term side effects. In addition, experience with this method has been gained in the weather modification community.

Ulrike Lohmann is full professor for experimental atmospheric physics in the Institute for Atmospheric and Climate Science at ETH Zürich since October 2004. Her research focuses on the role of aerosol particles and clouds in the climate system. She combines laboratory work and field measurements on cloud and aerosol microphysics with their representation in numerical models, machine learning and satellite data analysis. Her special focus is on clouds containing ice crystals. Lohmann obtained her Ph.D. in climate modelling from the Max Planck Institute for Meteorology in 1996. She was a post-doctoral fellow at the Canadian Centre for Climate (1996–97) and an assistant and associate professor at Dalhousie University in Halifax (1997–2004). Lohmann was awarded a Canada Research Chair in 2002, received the American Meteorological Society (AMS) Henry G. Houghton Award in 2007, was elected as a fellow of the American Geophysical Union in 2008 and of the German National Academy of Sciences, Leopoldina in 2014. She was a lead author for the Fourth and Fifth Assessment Reports of the Intergovernmental Panel for Climate Change. In 2018, she was awarded an honorary doctorate from Stockholm University, and in 2021, she obtained a European Advanced Council (ERC) advanced grant to study ice crystal growth processes in supercooled liquid clouds over Switzerland.