What is the PSI of the earth's atmosphere

Atmosphere in X-ray light

Ozone in the upper atmosphere protects us from dangerous UV radiation, but too much ozone in the air we breathe can endanger our health. Unless there is summer smog, the concentration of ozone in the lower layers of the atmosphere is harmless and largely constant. Because the processes in which ozone is formed or broken down are roughly balanced. Bromine and related chemical elements such as chlorine and iodine in the air make a significant contribution to this: Globally, they are responsible for around 50% of ozone depletion.

Ozone, in turn, is partly responsible for the formation of bromine in the atmosphere. This is because bromine is formed when bromide, which is contained in seawater, comes into contact with ozone from the air. This happens on the surface of the sea or on the surface of small droplets (fine dust) that are created when the spray is formed. Because 70% of the earth is covered by oceans, this is happening on a global scale on a large scale. Researchers at the Paul Scherrer Institute PSI have now determined the first details of this important chemical reaction. To do this, they simulated the processes on the surface of the water in a new experimental chamber and examined them using X-ray light from the Swiss SLS synchrotron light source at PSI. Theoretical calculations carried out by researchers at institutes in Switzerland, the USA and Qatar helped interpret the measurement results.

Worldwide unique research opportunities

The SLS is a large-scale research facility that generates particularly intense X-ray light, the properties of which can be precisely adapted to the needs of various experiments. The heart of the facility is a circular particle accelerator with a circumference of around 288 meters. With the X-ray light of the SLS, individual substances can be detected very precisely - even if they only exist for a very short time. , says Luca Artiglia, the responsible scientist. Markus Ammann, head of the surface chemistry research group at PSI, explains:. At the same time, they show that the experimental chamber set up by the researchers, which is unique in the world, actually enables the expected insights. Artiglia emphasizes.

Text: Paul Scherrer Institute / Paul Piwnicki