Tropospheric Chemistry: Instruments

ACES on aircraft

ACES deployed on NOAA WP-3D aircraft.

ACES (Airborne Cavity Enhanced Spectrometer)

Principle of the Measurement

Cavity enhanced spectroscopy uses two mirrors to create an optical path of several tens of kilometers within a 50 cm measurement cell, making the instrument very sensitive to absorption by trace gases.

Species Measured

glyoxal (CHOCHO), nitrous acid (HONO), nitrogen dioxide (NO2)

Time Response / Detection Limit

30 pptv / 10 seconds for glyoxal and NO2


Custom built for NOAA P-3 aircraft, also used for ground based measurements

Field Projects

  • SENEX 2013
  • UBWOS 2014
  • CARE-Beijing 2014
  • SONGNEX 2015


  • NOAA WP-3D aircraft
  • ground sites


Kyle Zarzana, Rebecca Washenfelder, Steve Brown

Key Publications

Min, K.-E., Washenfelder, R. A., Dubé, W. P., Langford, A. O., Edwards, P. M., Zarzana, K. J., Stutz, J., Lu, K., Rohrer, F., Zhang, Y., and Brown, S. S., A broadband cavity enhanced absorption spectrometer for aircraft measurements of glyoxal, methylglyoxal, nitrous acid, nitrogen dioxide, and water vapor, Atmos. Meas. Tech. Discuss., doi:10.5194/amtd-8-11209-2015, 2015.

Kaiser, J., Wolfe, G. M., Min, K. E., Brown, S. S., Miller, C. C., Jacob, D. J., deGouw, J. A., Graus, M., Hanisco, T. F., Holloway, J., Peischl, J., Pollack, I. B., Ryerson, T. B., Warneke, C., Washenfelder, R. A., and Keutsch, F. N., Reassessing the ratio of glyoxal to formaldehyde as an indicator of hydrocarbon precursor speciation, Atmos. Chem. Phys., doi:10.5194/acp-15-7571-2015, 2015.