This project investigates the water-uptake of aerosols from gasoline direct injection (GDI) vehicles using a mobile environmental chamber that has been designed and constructed to characterize secondary emissions, or emissions that have undergone atmospheric transformations. The cloud condensation nuclei (CCN) ability of aged aerosols are compared to fresh measurements. The fresh and aged emissions are characterized for CCN properties for a total of six light-duty GDI vehicles. Testing includes GDI vehicles with low and high mileage, vehicles operated with ethanol blends, and vehicles retrofitted with prototype gasoline particle filters.
The results of this study have important implications for the assessment of cloud-aerosol indirect effects of salt-seeded and black carbonaceous aerosol cores. The researchers concluded that in aerosol emissions from new generation GDI vehicles will have significant influence on the impacts of the secondary and primary aerosols on climate.