Atmospheric Aging Impacts on Particles for Cirrus Cloud Seeding

Cirrus cloud thinning is a potential framework to mitigate climate warming via short-lived climate forcers. Cirrus clouds forming at high altitudes in the troposphere composed only of ice crystals produce a net warming effect on Earth’s climate because they are optically thin and their ability to shield incoming solar radiation is outweighed by the trapping of outgoing longwave radiation (heat). In this work, we seek to investigate ice crystal formation pathways via laboratory experiments that could suppress natural cirrus formation, thus curtailing some of the atmospheric warming caused by natural cirrus clouds. By synthesizing particles and selecting natural particles with properties that promote ice crystal (and thus cirrus cloud) formation more readily than natural cirrus, we will identify the potential applicability of cirrus cloud thinning. This includes testing how the particles will age in the atmosphere in the presence of (in)organic acids, multiple cloud cycles, and how efficient they are at forming ice crystals under atmospherically relevant temperatures and humidities. This team is optimally combined to approach this problem via different techniques combining expertise from atmospheric chemistry, physics and materials chemistry.

Zamin A. Kanji obtained his Ph.D. in 2009 from the University of Toronto in atmospheric chemistry. After a postdoctoral stay at ETH Zürich and Environment and Climate Change Canada, he was appointed as a group leader of the experimental atmospheric physics group in the department of Environmental System Sciences at ETH Zürich in 2013. His main research interests include studying the properties of aerosols on liquid and ice cloud formation both via laboratory and field observations with a recent focus on black carbon and aviation soot–cirrus interactions. Kanji was elected to the International Commission on Cloud and Precipitation in 2021 and the committee on Nucleation and Atmospheric Aerosols in 2023 and serves on the departmental diversity, equity and inclusion committee at ETH Zürich.

Jonathan P. D. Abbatt is a chemistry professor at the University of Toronto, having received his Ph.D. from Harvard University in atmospheric chemistry. Abbatt’s research activities lie broadly in the areas of atmospheric aerosol and cloud chemistry, using both laboratory and field measurement techniques. His current research interests include cloud formation and multiphase chemistry studies related to the Arctic, wildfires and indoor environments. He is a fellow of the American Geophysical Union and the Royal Society of Canada.

Dominik Brühwiler obtained his Ph.D. in chemistry from the University of Bern in Switzerland in 2001. After a postdoctoral stay at the Lawrence Berkeley National Laboratory, he was appointed research group leader at the University of Zürich and completed his habilitation in 2011. In the same year, Brühwiler moved to the Zürich University of Applied Sciences, where he is currently the head of the section of polymer chemistry. His main research interests focus on the synthesis, functionalization and characterization of nanoporous materials. In 2019, Brühwiler was elected to the Research Council of the Swiss National Science Foundation.

Luis A. Ladino was born in Villavicencio, Colombia. In 2011, he obtained his Ph.D. in environmental sciences from the Swiss Federal Institute of Technology Zürich working on cloud microphysics. Currently, he is an associate professor for the Institute for Atmospheric Sciences and Climate at the National Autonomous University of Mexico. His main research interests focus on air quality, atmospheric aerosols, cloud microphysics and aerosol-cloud interactions. Ladino is a member of the International Commission on clouds and precipitation and the president of the Latin American and Caribbean Association for Aerosol Studies.