Researchers provide unprecedented view into aerosol formation in Earth’s lower atmosphere

Phys.org  March 6, 2024
Criegee intermediates are reactive intermediates that are implicated in transforming the composition of Earth’s troposphere and in the formation of secondary organic aerosol, impacting Earth’s radiation balance, air quality and human health. Direct identification of their signatures in the field are not available. An international team of researchers (USA – Argonne National Laboratory, NASA Jet Propulsion Laboratory, Sandia National Laboratory, Caltech, Princeton University, Princeton Plasma Physics Laboratory, UC Davis, UK, Turkey, Brazil, France) has identified sequences of masses consistent with the expected signatures of oligomerization of the CH2OO Criegee intermediate, a process implicated in ozonolysis-driven aerosol formation. Global atmospheric models indicated that Criegee intermediate chemistry may play a larger role in altering the composition of Earth’s troposphere than is captured in current atmospheric models. Resolving the remaining uncertainties in emission inventories and the effects of atmospheric water vapour on key chemical reactions will be required to definitively assess the role of Criegee intermediate oligomerization reactions… read more. TECHNICAL ARTICLE 

Theoretical verification of the CH2OO + formic acid sequence. Credit: Nature Geoscience, March 5, 2024