Retrieval of stratospheric vertical profiles of aerosol extinction coefficients from the Ozon-Mir measurements (Mir space station)

On the basis of data on the slant-path atmospheric transmittance measured w ith the Ozon-Mir instrumentation of the Mir space station, the vertical pro files of the volume aerosol extinction coefficient (VAEC) at 0.4, 0.7, and 1 mum were obtained in the height range from 13-18 to 35-40 km. The VAEC in herent error at a wavelength of 1 mum for the lower boundary of the height range under study is 5-8% and increases as the wavelength decreases and the height increases, ranging at all three wavelengths up to 50-100% for heigh ts of 35-40 km. The data of the measurements performed from December 1996 t o February 1997 are in the best quantitative accordance with the aerosol mo del of the background stratosphere LOWTRAN-7. The other available models [1 8, 19, 21] of a slightly turbid stratosphere give VAEC values that are 1.5- 5 rimes lower than the measured ones. A comparison of the retrieved profile s with the mean VAEC profiles obtained from the SAGE-II data is performed. The Ozon-Mir and SAGE-II data on aerosol extinction coefficients are in goo d agreement. The differences between them are close to the VAEC natural var iability, although the Ozon-Mir values are somewhat greater than the SAGE-I I mean values obtained in the corresponding months and latitudinal zones. A comparison between the Ozon-Mir and SAGE-I Angstrom coefficient values sho ws that these values are in satisfactory agreement. The SAGE-I and Ozon-Mir measurements under consideration were performed during the periods charact erized by the background stratospheric aerosol content even if significantl y separated in time.