We report car-borne measurements of atmospheric NO₂ close to the ground by incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS). A compact IBBCEAS spectrometer with a blue light emitting diode (LED) having a central wavelength of 458 nm, a full width at half maximum of 25 nm, and a 50-cm-long cavity was developed for mobile measurements. The NO₂ detection limit of the spectrometer was calculated as 1.9 parts per billion by volume (ppbv) for a 30 s acquisition time by stabilizing the LED emitting spectrum, optimizing the NO₂ reference cross sections, and by calibrating the reflectivity of the cavity mirrors. The accuracy of the spectrometer was verified by measuring NO2 samples with various mixing ratios between 1–200 ppbv, which were produced by a gas dilution system in the laboratory. Three distinct journeys in Nanjing and the surrounding areas were selected as observation routes. The atmospheric NO₂ close to the ground was measured by the spectrometer from August 4 to 7, 2013. The mixing ratios of NO₂ ranged from 3 to 144 ppbv. These results were compared with the column density of NO₂ measured by a passive differential optical absorption spectroscopy (DOAS) instrument on the same car. Hence, we demonstrate the feasibility of using the spectrometer for car-borne measurements of atmospheric NO₂.

我们报告了通过非相干宽带腔增强吸收光谱 (IBBCEAS) 对靠近地面的大气 NO ₂进行车载测量。紧凑型 IBBCEAS 光谱仪具有中心波长 458 nm、半高全宽 25 nm 和 50 cm 长腔的蓝色发光二极管 (LED)，用于移动测量。的NO ₂的分析装置的检测极限通过稳定LED发射光谱，优化NO计算为1.9份每十亿（体积）（ppbv的）对于30秒采集时间₂参考截面，并通过校准腔镜的反射率。通过测量实验室气体稀释系统产生的 1-200 ppbv 之间各种混合比的 NO2 样品来验证光谱仪的准确性。南京及周边地区的三个不同的旅程被选为观察路线。2013年8月4日至7日，近地面大气NO ₂由光谱仪测量，NO ₂混合比为3至144 ppbv。将这些结果与 NO ₂的柱密度进行比较通过在同一辆车上的无源差分光吸收光谱 (DOAS) 仪器进行测量。因此，我们证明了使用光谱仪对大气 NO ₂进行车载测量的可行性。