14 DAY TRIAL // For many years, researchers have been aware of the fact that the amounts of sulphuric acid in our atmosphere have been increasing constantly. However, models based on data retrieved through practical studies could not be correlated with simulations testing for the formation of the acid in the atmosphere. In other words, chemists had no idea where the extra acid was coming from. A new investigation by Finnish researchers at the University of Helsinki comes to clear this mystery, proposing a rather simple solution.
According to team leader Mikko Sipila, the issue was a rather straightforward one, which could have been easily avoided. Instruments used to collect samples from the atmosphere could only detect particles that were equal or larger than 3 nanometers in diameter. While this made them highly precise, the concentrations of particles smaller than that is apparently much larger than anyone thought. Sipila and his colleagues, all members of an international research team, took to devising methods of detecting particles as small as a nanometer in diameter, and were successful in their quest.
The expert also explains another mechanism that hindered previous investigations. He says that sulfuric acid particles condensing from gas are formed very slowly, especially at concentrations of below 10^8 molecules per cubic centimeter. “This means that within the residence times used in previous studies – some ten seconds typically – the particles cannot grow above the detection limit of the particle counters they have been using,” the team leader adds. Basically, he argues, the difference of several orders of magnitude, which until now existed between observed and simulated instances of sulphuric acid formation, does not exist.
Other scientists say that the new study is very interesting. If the work pans out to be accurate, then it could bear significant implications for the field of modeling the effects of global warming and climate change on the planet. Uncertainties related to the long-term action of aerosol particles in the atmosphere are currently a “wild card” in such models, and researchers are looking at methods of getting rid of them. “If the detailed molecular steps are not known it creates lots of uncertainty in these models. That's why it's very important to understand the detailed steps as this would then enhance the accuracy of global climate predictions,” Sipila concludes, quoted by Chemistry World.