HR: 17:29h
AN: A14A-06    [Abstracts]
TI: Measurements of Reactive Iodine Species on the Isles of Shoals, Gulf of Maine
AU: * Pikelnaya, O
EM: olga@atmos.ucla.edu
AF: University of California Los Angeles, Department of Atmospheric and Oceanic Sciences 7127 Math Sciences , Los Angeles, CA 90095-1565 United States
AU: Hurlock, S C
EM: steveh@atmos.ucla.edu
AF: University of California Los Angeles, Department of Atmospheric and Oceanic Sciences 7127 Math Sciences , Los Angeles, CA 90095-1565 United States
AU: Trick, S
EM: strick@atmos.ucla.edu
AF: University of California Los Angeles, Department of Atmospheric and Oceanic Sciences 7127 Math Sciences , Los Angeles, CA 90095-1565 United States
AU: Stutz, J
EM: jochen@atmos.ucla.edu
AF: University of California Los Angeles, Department of Atmospheric and Oceanic Sciences 7127 Math Sciences , Los Angeles, CA 90095-1565 United States
AB: The chemistry of reactive iodine species has received considerable attention in the past five years. The presence of iodine oxides in the marine boundary layer (MBL) can influence ozone levels, either through well-known catalytic destruction cycles, or through its influence on NO/NO₂ and OH/HO₂ ratios. In addition, iodine oxides have been linked to aerosol nucleation events in the MBL. Currently, the observational database on reactive iodine species is limited to a very few geographical locations, and the levels of reactive iodine compounds along the North American coast are currently unknown. This lack of information severely restricts our ability to assess the significance of iodine chemistry on a global scale. Here we present the first observations of IO, OIO, and I₂ on the Isles of Shoals, Gulf of Maine, during ICARTT 2004, using simultaneous measurements by long-path (LP) and a multi-axis (MAX) differential optical absorption spectroscopy (DOAS) systems.. Both instruments clearly identified reactive iodine species. IO mixing ratios reached 7ppt on several days. OIO was observed during the day, while I₂ was elevated at night. Our observations will be discussed with respect to the current knowledge of iodine chemistry, possible iodine sources, and the influence of iodine chemistry on ozone concentrations and aerosol nucleation. Prospects for deriving spatial distributions of reactive iodine species will also be discussed.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005