Atmospheric Composition & Chemical Processes: Instruments

Laser Induced Fluorescence Instrumentation for Nitric Oxide (NO-LIF)

NO instrument
NO-LIF instrument integrated on the NASA DC-8.

Nitrogen oxides are key species controlling many aspects of atmospheric radical chemistry throughout the atmosphere. The recent development in CSL of a single-photon laser induced fluorescence (LIF) technique for measuring nitric oxide (NO) has been demonstrated to provide the best currently available measurement of NO (lowest detection limit and uncertainty) while reducing some aspects of experimental effort compared to the more common chemiluminescence instrumentation. The new technique is anticipated to allow for better understanding of radical chemistry in very low-NO environments characteristic of much of the troposphere.

The existing instrument was designed for 19" rack-type integration on platforms such as the NASA DC-8. This instrument has two channels that can be used for simultaneous detection of NO and NO2 or NOy by using a photolytic or catalytic inlet converter. Ongoing work in our laboratory seeks to develop a version of this instrument by which NO2 is photolyzed to NO within the NO-LIF cell, thereby eliminating the need for an inlet converter for NO2 measurement. The use of the instrument to quantify isotopic ratios of NO is also currently being tested.

Comparison of NO-LIF and chemiluminescence techniques during the FIREX-AQ 2019 mission.
  • Detection limit: 1 pptv / 1 second
  • Accuracy: +/- 9%
  • Airborne time response: 5 Hz

Rollins, A. W., Rickly, P. S., Gao, R.-S., Ryerson, T. B., Brown, S. S., Peischl, J., and Bourgeois, I., Single-photon laser-induced fluorescence detection of nitric oxide and sub-parts-per-trillion mixing ratios, Atmospheric Measurement Techniques, doi:10.5194/amt-13-2425-2020, 2020.