A cavity-enhanced ultraviolet absorption instrument for high-precision, fast-time-response ozone measurements

[摘要] The NASA Rapid Ozone Experiment (ROZE) is a broadband cavity-enhanced UV (ultraviolet) absorption instrument for the detection of in situ ozone (O 3 ). ROZE uses an incoherent LED (light-emitting diode) light source coupled to a high-finesse optical cavity to achieve an effective pathlength of ∼  104 m. Due to its high sensitivity and small optical cell volume, ROZE demonstrates a 1 σ precision of 80 pptv (parts per trillion by volume) in 0.1 s and 31 pptv in a 1 s integration time, as well as an e -fold time response of 50 ms. ROZE can be operated in a range of field environments, including low- and high-altitude research aircraft, and is particularly suited to O 3 vertical-flux measurements using the eddy covariance technique. ROZE was successfully integrated aboard the NASA DC-8 aircraft during July–September 2019 and validated against a well-established chemiluminescence measurement of O 3 . A flight within the marine boundary layer also demonstrated flux measurement capabilities, and we observed a mean O 3 deposition velocity of 0.029  ±  0.005 cm s −1 to the ocean surface. The performance characteristics detailed below make ROZE a robust, versatile instrument for field measurements of O 3 .

[学科分类] 内科医学