Simultaneous profiling of O3 and NO2 in the lower troposphere by multiwavelength differential absorption lidar

Vertical concentration profiles of O-3 and NO2 in the lower troposphere were measured simultaneously using a multiwavelength differential absorption lidar (DIAL) system based on a pair of Nd:YAG pumped dye lasers each capable of emitting two wavelengths on alternate pulses. A mixture of Rhodamine 590 and Rhodamine 610 dyes and second harmonic generation was used to generate wavelengths 288.2 nm (on) and 293.5 nm (off) for 03 measurement, and sum frequency mixing of LDS765 dye laser radiation with Nd:YAG fundamental was used to generate wavelengths 448.1 nm (on) and 446.8 nm (off) for NO2 measurement. O-3 profiles of approximately 30-50 ppb and NO2 profiles of 0-20 ppb were obtained for vertical range 1500-2500 m. The measurement error was estimated to be <6 ppb for 150 m range resolution, or <0.9 ppm-m, for both O-3 and NO2.