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


Bill Dubé, Steve Brown