The distribution of sea-salt aerosol in the global troposphere

Academic Article

Abstract

  • Abstract. We present the first data on the concentration of sea-salt aerosol throughout most of the depth of the troposphere and over a wide range of latitudes, which were obtained during the Atmospheric Tomography (ATom) mission. Sea-salt concentrations in the upper troposphere are very small, usually less than 10 ng per standard m3 (about 10 parts per trillion by mass) and often less than 1 ng m−3. This puts stringent limits on the contribution of sea-salt aerosol to halogen and nitric acid chemistry in the upper troposphere. Within broad regions the concentration of sea-salt aerosol is roughly proportional to water vapor, supporting a dominant role for wet scavenging in removing sea-salt aerosol from the atmosphere. Concentrations of sea-salt aerosol in the winter upper troposphere are not as low as in the summer and the tropics. This is mostly a consequence of less wet scavenging in the drier, colder winter atmosphere. There is also a source of sea-salt aerosol over pack ice that is distinct from that over open water. With a well-studied and widely distributed source, sea-salt aerosol provides an excellent test of wet scavenging and vertical transport of aerosols in chemical transport models.
  • Authors

  • Murphy, Daniel M
  • Froyd, Karl D
  • Bian, Huisheng
  • Brock, Charles A
  • Dibb, Jack
  • DiGangi, Joshua P
  • Diskin, Glenn
  • Dollner, Maximillian
  • Kupc, Agnieszka
  • Scheuer, Eric M
  • Schill, Gregory P
  • Weinzierf, Bernadett
  • Williamson, Christina J
  • Yu, Pengfei
  • Status

    Publication Date

  • April 2, 2019
  • Published In

    Digital Object Identifier (doi)

    Start Page

  • 4093
  • End Page

  • 4104
  • Volume

  • 19
  • Issue

  • 6