IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Monday Sessions
       Session SS1-MoM

Paper SS1-MoM5
Sea Salt Aerosol Reactions: Quantitative Single Particle Studies

Monday, October 29, 2001, 11:00 am, Room 120

Session: Aerosol and Related Chemistry
Presenter: J.P. Cowin, Pacific Northwest National Laboratory
Authors: A.J. Laskin, Pacific Northwest National Laboratory
M.J. Iedema, Pacific Northwest National Laboratory
J.P. Cowin, Pacific Northwest National Laboratory
Correspondent: Click to Email
Sea salt from ocean wave action is a very common aerosol. This aerosol is far from inert, with several papers in recent years looking at how it can react with HNO3 to form sodium nitrate (releasing HCl), or hydroxyl radicals to form Cl2. We present highly quantitative, time resolved studies of sea salt aerosols observed during the fall 2000 Texas Air Quality Study. We used a novel automated sampler to preserve 3000 samples (10 minute intervals) for nearly a month of continuous observation. These were preserved for automated laboratory analysis with scanning electron microscopy/energy dispersed x-ray analysis. We analyze particles down to 0.2 micron in size for elements from carbon upward. We are able to follow these reactions in detail, and relate them to the time-resolved atmospheric gases seen by other researchers there. We are able to show that nitration occurs preferentially to sulfating (until later in the daily cycle). We are able to follow the size-resolved reaction, with as expected faster reactions for the smaller particles. We used the archived samples for other techniques too. High resolution time of flight secondary ion mass spectrometry gave important molecular speciation information, on a single particle basis (0.2 micron resolution).