Scientific Highlights

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.

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.

For years, studies have proved that fine dust from petrol engines can damage our health. Modern engine technology does not help, either, as researchers from the University of Bern and the Paul Scherrer Institute (PSI) reveal.

The causes of China's record level fine particulate pollution in winter 2013At the beginning of 2013 a greyish-brown blanket of smog lay over large areas of China for several months. The fine particle pollution was higher by 1 to 2 orders of magnitude than the levels normally measured in Western Europe and the United States. An international team of researchers under the lead of the Paul Scherrer Institute PSI and the Institute of Earth Environment, Chinese Academy of the Sciences revealed the causes of the airpocalypse. The study published in the journal Nature also describes what steps are to be taken to prevent an environmental crisis of this kind in the future.

In some towns small mopeds cause more air pollution than carsNot cars or trucks, but mopeds with their two-stroke engines are the main source of fine particles and other air contaminants in many towns in Asia, Africa and southern Europe. This is revealed by the study of an international research team headed up by researchers at the Paul Scherrer Institute PSI. The reasons for the high emissions are the combustion properties in two-stroke engines and the overly lenient emission requirements for small two-wheelers. The study findings are to be published on 13 May 2014 in the journal Nature Communications.

PSI-researcher Martin Gysel receives prestigious European funding (ERC Consolidator Grant) for his studies on the role of soot in cloud formation and global warming.