Mapping tropospheric ozone profiles from an airborne ultraviolet–visible spectrometer

We present a novel technique for retrieving ozone ͑O3͒ profiles and especially tropospheric O3 from airborne UV͞visible spectrometer measurements. This technique utilizes radiance spectra from one down-looking and two up-looking (85° and 75°) directions, taking advantage of the O3 absorption structure in the Huggins ͑300–340᎑nm͒ and Chappuis ͑530–650᎑nm͒ bands. This technique is especially sensitive to tropospheric O3 below and Յ8 km above the aircraft with a vertical resolution of 2–6 km and is sensitive to lower and middle stratospheric O3 with a vertical resolution of 8–15 km. It can measure tropospheric O3 at spatial resolutions of 2 km ϫ 2 km or higher and is therefore well suited for regional air-quality studies and validation of satellite measurements.