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LAC - Laboratory of Atmospheric Chemistry

The Laboratory of Atmospheric Chemistry (LAC), established 1 January 2000, is a laboratory of the Energy and Environment Research Division (ENE) at the Paul Scherrer Institute.
Our laboratory comprises four interacting groups that operate a large variety of facilities and instruments in the lab and in the field.


13 July 2017

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Gasoline cars produce more carbonaceous particulate matter than modern filter-equipped diesel cars

In contrast to nitrogen oxides, modern gasoline cars emit much more cancerogenic primary soot (black carbon + primary organic aerosol) and lead to more toxic secondary organic aerosol than modern diesel vehicles.

14 November 2016

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Swiss Aerosol Award 2016

Clouds, particulate matter and climate - a new study reveals surprises

27 October 2016

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The substances that brighten up the clouds

Media Releases Energy and Environment Environment

Clouds consist of tiny droplets. These droplets form when water condenses around so-called aerosols – small particles in the atmosphere. To understand how in turn aerosols come into existence scientists have now created a comprehensive computer model simulation based on profound experimental data. This simulation revealed that in addition to sulphuric acid, two other substances are crucially involved in the formation of aerosols: organic compounds and ammonia. These results have now been published in the renowned journal Science.

13 October 2016


Labile peroxides in secondary organic aerosol

Aerosols, suspended fine liquid or solid particles in the air we breathe, play a central role in many environmental processes through their influence on climate, the hydrological cycle, and their adverse effects on human health. While the mechanisms by which aerosol particles affect our health remain uncertain, the atmospheric oxidation of organic vapors has been shown to be related to the formation of oxygenated organic matter with high oxidative potential, the so-called reactive oxygen species (ROS). These species may damage our lung cells through oxidative stress. Also, if we want to understand the impact of human activity on our climate, we need to be able to reconstruct the conditions before the industrial era, and to determine the main ingredients responsible for the formation of aerosols and clouds. New results obtained from the cloud chamber at CERN revealed that new aerosol particles may originate from highly oxygenated organic molecules (HOMs). They are produced upon the oxidation of natural emissions and are composed of peroxides. This class of molecules seems to have important implications for climate and health.

26 May 2016

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Present-day measurements yield insights into clouds of the past

Media Releases Energy and Environment Environment

Researchers have shown how fine particles are formed from natural substances in the atmosphere. These findings will improve our knowledge about clouds in the pre-industrial era and thus will contribute to a more accurate understanding of both the past and future evolution of our climate.

9 May 2016

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Swiss chemist wins prestigious Royal Society of Chemistry Award

Professor Urs Baltensperger, from the Paul Scherrer Institute in Switzerland, is the Royal Society of Chemistry Spiers Memorial Award winner for 2016.

26 April 2016

Recognition as 'Highly Cited Researchers'

Two researchers of the Laboratory of Atmospheric Chemistry at PSI were recognized by Thomson Reuters as Highly Cited Researchers 2015. Their published articles rank in the top 1% most cited articles in their subject field for the year of publication.

The honored researchers are Urs Baltensperger, Head of the LAC, and André S. H. Prévôt, Head of the Gasphase and Aerosol Chemistry Group of the LAC.

Ernest Weingartner of FHNW is the third Highly Cited Researcher 2015 partially affiliated with PSI/LAC.

List of the highly cited researchers