1. Cloud Aerosol Research in the Marine Atmosphere (CARMA) A multi-year project to look primarily at the interaction of aerosols and clouds in the marine atmosphere. A concurrent, ancillary task has been to characterize, both chemically and physically, the aerosols in the MBL

2. Proposed CARMA-IV Goals Hygroscopicity climatology for litoral region Assess the relative importance of super- inversion mixing and below cloud aerosol on cloud optical depth Assess the impact of precipitation scavenging on MBL aerosol concentration

3. Potential New Goals Assess the importance of EC particles as CCN Evaluate the impact of chemistry on aerosol hygroscopicity during vertical transport in the MBL Explore relationship between individual particle hygroscopicity and bulk scattering hygroscopicity

4. Instruments for Proposed Goals

5. Instruments for Potential Goals

6. Hygroscopicity Parameters For light scattering dependence: For particle size dependence: DHGF’s (wet to dry diameter ratio)

7. Hygroscopicity data for Climatology