Heterogeneous iodine-organic chemistry fast-tracks marine new particle formation. | Academic Article individual record
abstract

The gas-phase formation of new particles less than 1 nm in size and their subsequent growth significantly alters the availability of cloud condensation nuclei (CCN, >30-50 nm), leading to impacts on cloud reflectance and the global radiative budget. However, this growth cannot be accounted for by condensation of typical species driving the initial nucleation. Here, we present evidence that nucleated iodine oxide clusters provide unique sites for the accelerated growth of organic vapors to overcome the coagulation sink. Heterogeneous reactions form low-volatility organic acids and alkylaminium salts in the particle phase, while further oligomerization of small -dicarbonyls (e.g., glyoxal) drives the particle growth. This identified heterogeneous mechanism explains the occurrence of particle production events at organic vapor concentrations almost an order of magnitude lower than those required for growth via condensation alone. A notable fraction of iodine associated with these growing particles is recycled back into the gas phase, suggesting an effective transport mechanism for iodine to remote regions, acting as a "catalyst" for nucleation and subsequent new particle production in marine air.

authors
publication outlet

Proc Natl Acad Sci U S A

author list (cited authors)
Huang, R., Hoffmann, T., Ovadnevaite, J., Laaksonen, A., Kokkola, H., Xu, W., ... O'Dowd, C.
publication date
2022
keywords
  • Marine New Particle Formation
  • Heterogeneous Reaction
  • Intermediate Oxidized Organics
  • Iodine
PubMed ID
35917351
identifier
647376SE
Digital Object Identifier (DOI)
start page
e2201729119
volume
119
issue
32