HR: 0830h
AN: B21F-0770    [PDF]
TI: Impact of air pollution on deposition of mineral dust: Implications for ocean productivity
AU: * Fan, S
EM: snf@gfdl.noaa.gov
AF: NOAA GFDL, Princeton University, Forrestal Campus, Princeton, NJ 08544 United States
AU: Horrowitz, L W
EM: lwh@gfdl.noaa.gov
AF: NOAA GFDL, Princeton University, Forrestal Campus, Princeton, NJ 08544 United States
AU: Levy, H
EM: hl@gfdl.noaa.gov
AF: NOAA GFDL, Princeton University, Forrestal Campus, Princeton, NJ 08544 United States
AU: Moxim, W J
EM: wm@gfdl.noaa.gov
AF: NOAA GFDL, Princeton University, Forrestal Campus, Princeton, NJ 08544 United States
AB: Atmospheric dust aerosols originating from arid regions are simulated in an atmospheric global chemical transport model. Based on model results and observations of dust oncentration, we hypothesize that Asian dust over the North Pacific is mostly hydrophilic and removed efficiently by both ice and droplet nucleation processes. By contrast, African dust over the tropical Atlantic is mostly hydrophobic and removed by ice, but not droplet, nucleation. We suggest that Asian dust is transformed into hydrophilic aerosols by chemical reactions with air pollutants over East Asia, which produce high levels of readily soluble materials on the surface of dust particles. A model of chemical aging will be presented for the hygroscopic transformation of mineral dust in the atmosphere. The model predicts that evolving air pollution in East Asia could have caused an increase of dust deposition to the coastal oceans off Asia and a decrease by as much as 50 percent in the eastern North Pacific. Insofar as iron from dust deposition fuels diatom blooms in the North Pacific Ocean, this decrease could have potential consequences on ocean biology.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0320 Cloud physics and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
DE: 1615 Biogeochemical processes (4805)
DE: 4845 Nutrients and nutrient cycling
SC: Biogeosciences [B]
MN: 2003 Fall Meeting