Impact of Reactive Halogen Species on the Air Quality in Southern California Coastal Areas
EMSL Project ID
25613
Abstract
Air pollution in coastal urban centers remains one of the most serious environmental challenges in the State of California, and further efforts to improve air quality are a priority. Mitigation strategies often depend on accurate simulations with urban airshed models, which are currently based on the known chemistry of NOx, HOx, and VOC's. However, despite growing observational evidence for the presence of reactive halogen species (RHS) in the marine boundary layer and their known influence on ozone, their chemistry is currently not included in airshed models of California coastal areas. This is, in part, a consequence of the lack of atmospheric observations along the California coast, that would allow the assessment of the impact RHS on urban air quality. Motivated by the potential impact of reactive halogen chemistry on urban air pollution, the lack of experimental data to provide evidence for the presence of RHS, and the desire to contribute to the improvement of urban air quality models for coastal areas, we have conducted a three week field experiment in Malibu, CA (Oct. 2006) using an array of the instruments deployed during the experiment to provide a comprehensive data set on halogen chemistry. The measurements and samples are now being analyzed to assess the impact of reactive halogens on the chemistry of ozone in the polluted marine atmosphere and to study the sources of RHS. These include a correlation analysis of parameters such as wind direction and speed, tidal high, actinic flux, aerosol surface area, etc. to determine the behavior of halogen species as well as their sources. The samples of aerosol particles will be subject to comprehensive composition analyses using electron microscopy/probe techniques available at the Environmental Molecular Sciences Laboratory (EMSL).
Project Details
Project type
Large-Scale EMSL Research
Start Date
2007-06-20
End Date
2008-06-22
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members