The inversion method for simultaneous gas (O3, NO2, HNO3, N2O, CH4, H2O, CFC-11, CFC-12, N2O5, and ClONO2) and aerosol retrievals from broadband continuous IR spectra of occultation measurements is described. Both gas and aerosol physical modeling with consideration of the multicomponent character of aerosol and polar stratospheric clouds (PSCs) are used to minimize the difference between measured and modeled transmittance spectra under smoothness constraints imposed on particle-size distributions for each PSC component and positive constraints on all gas and aerosol parameters. The method is tested by numerical simulations in which synthetic occultation measurements inherent to the improved limb atmospheric spectrometer are used. The study reveals that the method has significant advantages over other approaches based on offset or gas-window-channel aerosol correction for accurate gas retrievals and provides additional information on the particle-size composition, volume density, and chemical component character of PSCs.
© 2005 Optical Society of America
(010.1280) Atmospheric and oceanic optics : Atmospheric composition
(280.0280) Remote sensing and sensors : Remote sensing and sensors
(280.1100) Remote sensing and sensors : Aerosol detection
Sergey Oshchepkov, Yasuhiro Sasano, Tatsuya Yokota, Nobuyuki Uemura, Hisashi Matsuda, Yasuhiro Itou, and Hideaki Nakajima, "Simultaneous stratospheric gas and aerosol retrievals from broadband infrared occultation measurements," Appl. Opt. 44, 4775-4784 (2005)