Atmospheric aerosols and how they influence climate
Climate models are evolving, and are getting more accurate, but they are still incomplete. Our atmosphere is very complex, and there are factors that even current models don't address, or address with an in-complete knowledge of the physical processes involved. This leads to inaccuracies that create uncertainty in the results of climatic projections. Aerosols are an important part of atmospheric dynamics, and their mechanisms of formation are not fully understood.
University of Leeds experts have helped scientists get a step closer to understanding how aerosol particles are formed in the atmosphere and the effect these particles have on our climate.
Working with scientists from the CLOUD experiment at the European Organisation for Nuclear Research (CERN), in Geneva, climate change experts from the University have shown that amines — atmospheric vapours closely related to ammonia, largely derived from activities such as animal husbandry — combine with sulphuric acid to form highly stable aerosol particles at rates similar to those observed in the lower atmosphere.
To conduct the experiment, the research team has access to a special laboratory chamber with unprecedented cleanliness, allowing them to simulate the atmosphere and introduce minute amounts of various atmospheric vapours under carefully controlled conditions — in this case amines and sulphuric acid.
The results of the experiment, published in the journal Nature, are significant because aerosols cause a cooling effect by reflecting sunlight and by seeding cloud droplets, suggesting that both natural and sources of amines caused by man could influence climate.
The team has also shown that ionisation by cosmic rays are unimportant when it comes to generating of these particular aerosol particles in the atmosphere.
The effect of cosmic rays on climate has been a highly controversial topic. It has been suggested that cosmic ray-induced particle formation could affect climate change, but this seems not to be the case for the particles studied at CERN.
Hazy landscape photo via Shutterstock.
Read more at University of Leeds.