14 DAY TRIAL // While, on selected days, the air may seem clean, fresh and transparent, there are actually thousands of very complex processes going on in the atmosphere each second. Large particles disintegrate into smaller ones, whereas smaller ones clog around airborne material, and form larger particles. Experts admit that it's very difficult to attempt to understand the complex correlations that determine the atmospheric equilibrium we are accustomed to, without accounting for all of these processes. However, some of the main changes can be tracked by keeping tabs on just a few of these events, researchers add.
A team of scientists recently set out to determine how fine particulates – the very small matter that clogs our lungs and also causes pollution and seeds clouds – were formed. Though they are universally acknowledged as real, Science has found it difficult until now to explain how they appear. The leader of the new project, Paul Scherrer Institute expert Andre Prevot, says that, in order to get a good idea of the effects that a single chemical has in the atmosphere, one simply needs to take into account the chemical properties that that specific stuff has.
“For example, the ratio of oxygen to carbon in a substance affects its ability to absorb water – and is therefore relevant to the ability of fine particulates to seed clouds,” Prevot says. The new line of research, which was aimed at identifying all possible sources for fine particulates, was only made possible by the fact that the team benefited from the help of a new type of measuring device, called a special mass spectrometer. These machines are capable of breaking down light into its component wavelengths, and determine the source of each of them, the experts say.
The research group looked at measurements taken from 26 locations around the Northern Hemisphere, and determined that the composition of the particulates was roughly the same in all corners of the world. This makes sense when considering that the stuff is basically generated by the same atmospheric processes, the specialists say. “We were able to use these results in conjunction with a complex statistical process to determine the type of source materials from which the fine particulates had originated. Additional procedures, such as the C14 method, can then be used to establish the exact sources – whether, for example, substances come from woodland or from exhaust gases,” the PSI Head of the Atmospheric Chemistry Laboratory, Urs Baltensperger, adds, quoted by ScienceDaily.