HR: 17:07h
AN: A14A-05 INVITED     [Abstracts]
TI: Iodine chemistry at polar and mid-latitudes
AU: * Plane, J M
EM: j.plane@uea.ac.uk
AF: University of East Anglia, School of Environmental Sciences, Norwich, NR4 7Tj United Kingdom
AU: Saiz-Lopez, A
EM: a.saiz-lopez@uea.ac.uk
AF: University of East Anglia, School of Environmental Sciences, Norwich, NR4 7Tj United Kingdom
AU: Saunders, R E
EM: r.saunders@uea.ac.uk
AF: University of East Anglia, School of Environmental Sciences, Norwich, NR4 7Tj United Kingdom
AU: McFiggans, G B
EM: gordon.b.mcfiggans@manchester.ac.uk
AF: University of Manchester, School of Earth, Atmospheric & Environmental Sciences , Manchester, M60 1QD United Kingdom
AU: Salmon, R A
EM: R.A.Salmon@bas.ac.uk
AF: British Antarctic Survey, High Cross Madingley Road, Cambridge, CB3 0ET United Kingdom
AU: Bauguitte, S
EM: sbau@pcmail.nerc-bas.ac.uk
AF: British Antarctic Survey, High Cross Madingley Road, Cambridge, CB3 0ET United Kingdom
AU: Jones, A
EM: a.jones@bas.ac.uk
AF: British Antarctic Survey, High Cross Madingley Road, Cambridge, CB3 0ET United Kingdom
AU: Mahajan, A
A14A-05 AF: University of East Anglia, School of Environmental Sciences, Norwich, NR4 7Tj United Kingdom
AB: Iodine oxide chemistry affects the oxidising capacity of the atmosphere in several important ways, and also produces condensable vapors which can form ultra-fine aerosol particles. In this paper we will first summarize recent laboratory work on the gas-phase chemistry of OIO, and on the kinetics of iodine oxide particle formation and growth. This will form the basis for interpreting field measurements of IO and OIO in the mid-latitude marine boundary layer at Mace Head, Ireland (the NAMBLEX campaign), and in the polar boundary layer at Halley Bay, Antarctica (the CHABLIS campaign). For the mid-latitude case, we will focus on modelling the night-time chemistry of iodine, where the nitrate radical appears to play an important role, and also on the phenomenon of ultra-fine particle bursts which occur during daytime when macro-algae are exposed at low tide. A year-long data set of IO observations from Antarctica show a strong seasonal cycle: maximum in spring, minimum during polar night. During summer, there is a clear dependence on solar intensity and wind direction, providing a strong indication of an iodine source in the snowpack as well as the ocean. The effects of these iodine emissions on the oxidising capacity of the polar boundary layer and the production of ultra-fine aerosol will be explored.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0317 Chemical kinetic and photochemical properties
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005