Evaluation of ozone column amount from the solar backscattering spectra measured with a spectrograph onboard an aircraft

Abstract

Abstract Slant column amounts of ozone were evaluated from the solar backscattered spectra measured with a simple spectrograph onboard an aircraft over the Pacific Ocean south of Japan in January 2002. A least-squares fitting method optimized on the basis of Bayesian statistics was developed to evaluate them, and the random error in the fitting was about 2.4%. The evaluated slant column amounts of ozone were compared with those calculated from the total ozone data measured with the Total Ozone Mapping Spectrometer (TOMS) on the same day. The differences between the two ranged from a few percent points to more than 20%, and they increased when a small wavelength deviation in the spectrograph occurred due to the aircraft vibration. Excluding the error due to this wavelength deviation, instrumental and systematic errors were estimated to be less than 10%, demonstrating that this airborne measurement with the spectrograph and the developed fitting method could evaluate the ozone column amount with a good accuracy.