A new multi-analysis aerosol reactor system(MAARS) has been designed for laboratory studies of atmospheric aerosol and their impact on climate. The aerosol flow reactor can employ three different aerosol generators – a nebulizer, an electrospray atomizer, and a fluidized bed generator. The aerosol flow reactor is being implemented in several different ways. The instrument can be used to:

1. measure the optical constants of the components of mineral dust aerosol by simultaneously measuring particle size distributions using both the SMPS (scanning mobility particle sizer) and APS (aerodynamic particle sizer) and the FTIR extinction spectrum of these particles. These sizing instruments allow us to measure the full range of particle sizes from 10 nm to 20 microns;

2. measure the ability of mineral dust particles to nucleate clouds. In these experiments the aerosol flow is directed to a CCN counter where the supersaturation ratio can be determined;

3. measure hygroscopic response of size-selected aerosol particles. For particles that undergo a phase transition from solid to liquid (deliquescence), the deliquescence relative humidity can be accurately determined. The particles are size selected by first being sent through the differential mobility analyze labeled DMA 1 in the schematic below.