Water uptake properties of organic matter (OM) are critical
for
aerosol direct and indirect effects. OM contains various chemical
species that have a wide range of water solubility. However, the role
of water solubility on water uptake by OM has poorly been investigated.
We experimentally retrieved water solubility distributions of water-soluble
OM (WSOM) from combustion of mosquito coil and tropical peat using
the 1-octanol–water partitioning method. In addition, hygroscopic
growth and cloud condensation nuclei (CCN) activity of solubility-segregated
WSOM were measured. The dominant fraction of WSOM from mosquito coil
smoldering was highly soluble (water solubility (S) > 10–2 g cm–3), while that
from peat combustion contained ∼40% of less-soluble species
(S < 10–3 g cm–3). The difference in water solubility distributions induced changes
in the roles of less water-soluble fractions (S <
10–3 g cm–3) on CCN activity.
Namely, the less water-soluble fraction from mosquito coil combustion
fully dissolved at the point of critical supersaturation, while that
for tropical peat smoldering was limited by water solubility. The
present result suggests that water solubility distributions of OM,
rather than its bulk chemical property, need to be quantified for
understanding the water uptake process.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.