Accession Number : ADA322525

Title :   Aerosol Physicochemistry at Christmas Island: Links to the Oceanic Sulfur Cycle.

Descriptive Note : Final rept. 1 Oct 93-15 Oct 96,

Corporate Author : HAWAII UNIV HONOLULU DEPT OF OCEANOGRAPHY

Personal Author(s) : Clarke, Antony D.

PDF Url : ADA322525

Report Date : 24 FEB 1997

Pagination or Media Count : 9

Abstract : The origin of new particles that can replace those scavenged by precipitation processes etc. in the marine boundary layer has been a focus of research for many years. We have demonstrated for the first time that diurnal processes in the marine boundary layer related to both aerosol formation and transformation can be observed in the dynamic response of the aerosol size distribution. We were able to show that new particle production was negligible in this region and that heterogeneous conversion information of sulfate took place on existing aerosol. We also demonstrated that subsidence (as evidence by ozone variability) contributed new nuclei into the boundary layer from aloft and that cloud processing and heterogeneous chemistry 'grew' them to larger sizes. This process was shown to be modulated by diurnal photochemistry. We have also developed a thermal DMA system that demonstrated that sea-salt particles from breaking waves extend down to sizes as small as 10 nm and that these particles can be distinguished from other aerosol (eg. sulfate) based upon their volatility.

Descriptors :   *AEROSOLS, *CYCLES, *SULFUR, *OCEANS, *PHYSICOCHEMICAL PROPERTIES, *CHRISTMAS ISLAND, PARTICLE SIZE, PHOTOCHEMICAL REACTIONS, DYNAMIC RESPONSE, BOUNDARY LAYER, VARIATIONS, MARINE ATMOSPHERES, PRECIPITATION, HETEROGENEITY, VOLATILITY, SULFATES, MODULATION, OZONE, DIURNAL VARIATIONS, NUCLEI, AEROSOL GENERATORS.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Physical and Dynamic Oceanography
      Geology, Geochemistry and Mineralogy

Distribution Statement : APPROVED FOR PUBLIC RELEASE