Tropospheric Chemistry: Instruments

HNO3 instrument in aircraft

HNO3 instrument (left) mounted in NOAA WP-3D aircraft.

Nitric Acid (HNO3)

Principle of the Measurement

Chemical Ionization Mass Spectrometry (CIMS) using SiF5- ion chemistry

Species Measured


Time Response

1 Second

Detection Limit

Precision on 1s data: 20 pptv (1 sigma)


±(15% + 100 pptv)


custom built

Field Projects

  • SOS 1999
  • TexAQS 2000
  • ITCT 2002
  • ICARTT 2004
  • Mesa 2005
  • TexAQS 2006
  • ARCPAC 2008 (used to measure halogens)
  • CalNex 2010
  • SENEX 2013


Andy Neuman

Key Publications

Neuman, J. A., L. G. Huey, R. W. Dissly, F. C. Fehsenfeld, F. Flocke, J. C. Holecek, J. S. Holloway, G. Hübler, R. Jakoubek, D. K. Nicks Jr., D. D. Parrish, T.B. Ryerson, D. T. Sueper, and A. J. Weinheimer, Fast-response airborne in situ measurements of HNO3 during the Texas 2000 Air Quality Study, J. Geophys. Res., 107(D20), 4436, doi:10.1029/2001JD001437, 2002.

Neuman, J. A., T. B. Ryerson, L. G. Huey, R. Jakoubek, J. B. Nowak, C. Simons, and F. C. Fehsenfeld, Calibration and evaluation of nitric acid and ammonia permeation tubes by UV optical absorption, Environ. Sci. Technol., 37, 1975-2981, doi:10.1021/ES06422L, 2003.