The role of highly oxygenated organic molecules in the Boreal aerosol-cloud-climate system.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31554809.
- Also identified by DOI 10.1038/s41467-019-12338-8 and PMC identifier 6761173.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Over Boreal regions, monoterpenes emitted from the forest are the main precursors for secondary organic aerosol (SOA) formation and the primary driver of the growth of new aerosol particles to climatically important cloud condensation nuclei (CCN). Autoxidation of monoterpenes leads to rapid formation of Highly Oxygenated organic Molecules (HOM). We have developed the first model with near-explicit representation of atmospheric new particle formation (NPF) and HOM formation. The model can reproduce the observed NPF, HOM gas-phase composition and SOA formation over the Boreal forest. During the spring, HOM SOA formation increases the CCN concentration by ~10 % and causes a direct aerosol radiative forcing of -0.10 W/m<sup>2</sup>. In contrast, NPF reduces the number of CCN at updraft velocities < 0.2 m/s, and causes a direct aerosol radiative forcing of +0.15 W/m<sup>2</sup>. Hence, while HOM SOA contributes to climate cooling, NPF can result in climate warming over the Boreal forest.