Aerosol Indirect Effect on Air Pollution-Meteorology Interaction in an Urban Environment

Using a fully coupled air quality prediction model, simulations were carried out to investigate the impact of aerosol indirect effect on air pollution-meteorology interaction in an urban environment. We found that the aerosol indirect effect results in an increase in cloud droplet number concentration, a reduction in cloud droplet size, and an increase in cloud water. While, as a result, precipitation production is suppressed in low-level clouds, we found that, in a case of deep convective clouds, there is an enhancement of cloud ice and precipitation production at higher levels due to the increase in abundance of smaller drops being carried up in the updraft. There is also an indication of enhanced convective activity due to urban heating.