Schiff, H.I.Karecki, D.R.Harris, G.W.Hastie, D.R.Mackay, G.I.2010-05-202010-05-201990J. Geophys. Res., 95, 10,147-10,153http://hdl.handle.net/10315/4114The advantages of tunable diode laser absorption spectrometry (TDLAS) for measuring trace atmospheric gases are universality, positive identification, good sensitivity, and rapid response time. A TDLAS system is described which is capable of making measurements on board an aircraft. The instrument was employed during the Chemical Instrumentation Test and Evaluation (CITE) 2 program to measure NO2, on 11 flights and HNO3, on five flights. Detection limits were determined to be 25 parts per trillion by volume [pptv] for NO2 and 75 pptv for HNO3 with response times of 3 min. This was sufficient to permit measurements of NO2 in the free troposphere and HNO3, in the continental boundary layer a significant fraction of the time.enArticlehttp://www.agu.org/journals/jd/