HR: 0800h
AN: A51C-0799    [Abstracts]
TI: Evaluation of a CIMS Technique used for Airborne Measurements of Ammonia during the New England Air Quality Study 2004
AU: * Nowak, J B
EM: John.Nowak@noaa.gov
AF: CIRES, University of Colorado, Boulder, CO 80309
AU: * Nowak, J B
EM: John.Nowak@noaa.gov
AF: NOAA Aeronomy Laboratory, 325 Broadway, R/AL-7, Boulder, CO 80305
AU: Neuman, J A
AF: CIRES, University of Colorado, Boulder, CO 80309
AU: Neuman, J A
AF: NOAA Aeronomy Laboratory, 325 Broadway, R/AL-7, Boulder, CO 80305
AU: Yoshida, K
AF: Harvey Mudd College, 301 E. 12th Street, Claremont, CA 91711
AU: Ryerson, T B
AF: NOAA Aeronomy Laboratory, 325 Broadway, R/AL-7, Boulder, CO 80305
AU: Huey, L G
AF: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332
AU: Tanner, D J
AF: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332
AU: Fortin, T J
AF: CIRES, University of Colorado, Boulder, CO 80309
AU: Fortin, T J
AF: NOAA Aeronomy Laboratory, 325 Broadway, R/AL-7, Boulder, CO 80305
AU: Holloway, J S
AF: CIRES, University of Colorado, Boulder, CO 80309
AU: Holloway, J S
AF: NOAA Aeronomy Laboratory, 325 Broadway, R/AL-7, Boulder, CO 80305
AU: Hubler, G
AF: CIRES, University of Colorado, Boulder, CO 80309
AU: Hubler, G
AF: NOAA Aeronomy Laboratory, 325 Broadway, R/AL-7, Boulder, CO 80305
AU: Parrish, D D
AF: NOAA Aeronomy Laboratory, 325 Broadway, R/AL-7, Boulder, CO 80305
AU: Sueper, D T
AF: CIRES, University of Colorado, Boulder, CO 80309
AU: Sueper, D T
AF: NOAA Aeronomy Laboratory, 325 Broadway, R/AL-7, Boulder, CO 80305
AU: Fehsenfeld, F C
AF: NOAA Aeronomy Laboratory, 325 Broadway, R/AL-7, Boulder, CO 80305
AB: A Chemical Ionization Mass Spectrometer (CIMS) utilizing protonated acetone dimer ion chemistry was used to measure gas-phase ammonia (NH$_{3}$) aboard the NOAA WP-3D aircraft during the New England Air Quality Study (NEAQS) in July and August of 2004. The protonated acetone dimer reacts selectively and sensitively with NH$_{3}$ to form a stable cluster ion. Ambient NH$_{3}$ was measured once per second by monitoring this cluster peak. A PFA Teflon inlet designed and previously characterized for sampling nitric acid (HNO$_{3}$) was used. The instrumental background was determined by scrubbing NH$_{3}$ from ambient air using silicon phosphates that release phosphoric acid when exposed to ambient levels of humidity. Standard addition calibrations were performed periodically during each flight using an NH$_{3}$ permeation device whose output was monitored throughout the field campaign by UV optical absorption at 184.95 nm. Preliminary data indicate a typical sensitivity of 2 to 3 ion counts/s/pptv of NH$_{3}$. Instrumental background varied between flights and typically ranged from 0.5 to 1 ppbv. Characterization of this inlet for sampling NH$_{3}$ and analysis of instrument time response will be presented and compared to laboratory studies of different inlet materials. Preliminary observations of tropospheric NH$_{3}$ mixing ratios downwind of East coast urban regions will be described.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0365 Troposphere--composition and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting