Andrea Baccarini, former member of the Laboratory of Atmospheric Chemistry, awarded the ETH Medal for his PhD thesis

Andrea Baccarini, a former PhD student at the Laboratory of Atmospheric Chemistry, has been awarded the ETH Medal for his thesis investigating aerosol formation in the Arctic and Antarctic and the role aerosols play in climate change.

Andrea Baccarini investigated aerosol formation in the Arctic

The journey undertaken by Andrea Baccarini for his PhD has indeed been special. It comprised a research expedition in the Arctic and one in the Antarctic, thousands of hours of field measurements and thousands more hours of lab work and data analysis, and joint experiments with scientists at CERN and various universities. He has now been recognized for this outstanding effort as a recipient of the ETH Medal for his thesis, which he defended in December 2020. The ETH Medal is a prestigious distinction given out every year to particularly remarkable, innovative thesis projects.

Baccarini spent the four years of his PhD studying new aerosol particle formation in polar regions. These airborne particles play a key role for the climate system. “Aerosols are essential for forming clouds, which can both warm up or cool off the planet,” says Baccarini. “If the aerosols’ properties or concentration change, that can have an impact on the Earth’s temperature.”

Aerosols are produced from a variety of sources, which can be either natural or anthropogenic. Sources of aerosols in polar regions are still poorly understood due to a lack of available data. However, thanks to Baccarini’s measurements, the picture has become a little clearer. For example, iodine emissions were a primary source of aerosol formation in the central Arctic Ocean, we found.

Hard work, commitment and unique opportunities

After obtaining a Master’s degree in experimental physics from the University of Trento (Italy), Baccarini joined the Laboratory of Atmospheric Chemistry (LAC) as a PhD student in the Molecular Cluster and Particle Processes group (now known as Environmental molecular science group), under the supervision of Dr. Josef Dommen. “I had to work hard during my PhD, but it was also a lot of fun,” says Baccarini. “The LAC is a great working environment, as a PhD student there I was given unique opportunities like taking part in expeditions to both the Arctic and Antarctic. I owe a lot to all the people that I worked with during my time at the LAC and I am particularly grateful to my supervisors, Dr. Josef Dommen, Prof. Urs Baltensperger and Prof. Julia Schmale, for their continuous support throughout my PhD journey.”

A research balloon for high-altitude measurements

Today Baccarini is a postdoc in the Extreme Environments Research Laboratory at EPFL; where he’s trying to take his research further, yet always towards the same goal: applying methods from experimental physics to solve concrete problems and have a real impact. He’s working on the development of an instrumented tethered balloon that can fly to about 800 meters above ground level. “The two research expeditions I took part in during my PhD were on ships, and we took measurements only at the water’s surface,” says Baccarini. “But we know that important processes also take place at higher altitudes. Being able to collect data at these altitudes will give us additional insight and help us better understand aerosol properties and their effects on clouds and the climate.”

Baccarini’s thesis research has been published in Nature Communications, Journal of Geophysical Research: Atmospheres and Bulletin of the American Meteorological Society.


Andrea Baccarini
Former member of the Laboratory of Atmospheric Chemistry at PSI

Dr. Imad El Haddad
Acting head of the Laboratory of Atmospheric Chemistry at PSI
Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
Telephone: +41 56 310 29 95, e-mail: