In a modeling study exploring the importance of retaining dissolved non-reactive chemical species during the freezing of cloud drops in deep convection, it was found that the freezing of drops through riming (snow and cloud water riming and hail and cloud water riming) played an important role in moving highly soluble species from the updraft region of a convective storm to the precipitation region. When chemically active species are represented in the convective cloud model, the distribution of soluble chemical species may also be controlled by the chemical reactions occurring in either the gas phase or the aqueous phase or both phases. This study examines the relative importance of gas-phase reactions, aqueous-phase reactions, transport, and transfer of species by microphysical processes for the convective storm simulated (10 July 1996 STERAO storm). Determining whether chemical reactions are important in convection during the transport or washout of a species to its vertical distribution can guide large-scale models that must parameterize convection.

Preliminary results suggest that transport controls the vertical distribution of ozone, gas-phase chemistry controls the vertical distribution of nitrogen oxides, aqueous-phase chemistry is important to the vertical distribution of sulfur dioxide, while the transfer via microphysical processes of formaldehyde plays an important role to its vertical distribution. Details of which chemical reactions and which microphysical processes contribute to these results will be presented.