HR: 1340h
AN: A33B-1190    [Abstracts]
TI: Quantifying Tropospheric Peroxy Radicals using Chemical Ionization Mass Spectroscopy with Chemical Conversion
AU: * Anderson, R S
EM: rsa@ucar.edu
AF: National Center for Atmospheric Research, 3450 Mitchell Lane, Boulder, CO 80301, United States
AU: Cantrell, C A
EM: cantrell@ucar.edu
AF: National Center for Atmospheric Research, 3450 Mitchell Lane, Boulder, CO 80301, United States
AB: We report the development of a mass spectrometric technique for the measurement of tropospheric peroxy radicals, particularly from aircraft platforms. This method makes use of chemical reactions involving added nitric oxide and sulfur dioxide reagent gases and dilution with nitrogen or oxygen (oxygen dilution modulation). This chemistry specifically converts HO₂ radicals to gas-phase sulfuric acid in one mode (high reagent concentrations and dilution with nitrogen) and converts HO₂ and most RO₂ radicals in the other mode (low reagent concentrations and dilution with oxygen). We have performed extensive laboratory assessments of the instrument response over a range of environmental conditions to a wide variety of radical species. This instrument has been deployed in several recent campaigns (MIRAGE, INTEX-B, PASE). Data from those campaigns will be used to illustrate the performance of the instrument.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting