Observationally constrained analysis of sea salt aerosol in the marine atmosphere

Sea salt is the largest contributor to atmospheric aerosol mass. Sea salt aerosol regulates marine cloud formation, provides a sink for reactive gases, and is a source of halogens to the atmosphere. We present a systematic and comprehensive global sea salt study by integrating NASA GEOS model simulations run with the GOCART aerosol module with ATom in situ measurements from the PALMS and SAGA instruments, as well as AOD measurements from AERONET Marine Aerosol Network (MAN) sun photometers and satellite observations over the oceans from MODIS. This study covers remote regions over the Pacific, Atlantic, and Southern Oceans, from near the surface to 12 km altitude and covers both summer and winter seasons. Important atmospheric sea salt fields, e.g. mass mixing ratio, vertical distribution, size distribution, and marine aerosol AOD, are examined. Sea salt aerosol relationship to relative humidity and the simulation of emission, dry deposition, sedimentation, and large scale and convective wet deposition processes are explored to explain the observed sea salt fields and to reveal potential directions for model improvement.