1. THE HYGROSCOPICITY OF ORGANICS IN THE OCEAN Rachel Chang Physics and Atmospheric Science NETCARE Meeting, University of Toronto Nov 3, 2014

2. OBJECTIVES to determine the effect of the organic fraction of marine aerosol on its CCN- activity to compare this effect over different seasons

3. MOTIVATION Scripps Institute Prather, Proc Nat Acad Sci, 2013 Mass Fraction (%) Mass Conc (µg/m 3 ) Mace Head, Ireland - O’Dowd, Nature, 2004 WSOC WIOC Sea Salt nss-SO 4

4. ORGANICS IN MARINE AEROSOL Atlantic Ocean – Quinn, Nature Geoscience, 2014 Hygroscopicity NaCl Sea Sweep Aerosol Organic Volume Fraction Organic SO 4 NO 3 MSA Arctic Ocean Chang, ACP, 2011

5. SEASONAL STUDIES Quinn, Nature Geoscience, 2014Collins, J. Geophys. Res., 2013

6. APPROACH extract an organic fraction from the North Atlantic Ocean aerosolize the organics to form aerosol measure CCN-activity

7. IMPORTANCE OF ISOLATING ORGANIC COMPONENT Δ D act (nm) Increasing Effect of Inorganic

8. SAMPLING ORGANICS surface microlayer – glass slide –seasurface microlayer –lakewater microlayer ocean surface water – solid phase extraction other suggestions?