Retrieval of stratospheric aerosol size and composition information from solar infrared transmission spectra.

摘要: Infrared transmission spectra were recorded by the Jet Propulsion Laboratory MkIV interferometer during flights aboard NASA DC-8 aircraft as part of Airborne Arctic Stratospheric Expedition II (AASE II) mission in early months 1992. In our research, we infer properties stratospheric aerosols from these spectra. The instrument employs two different detectors, a HgCdTe photoconductor for 650–1850 cm-1 and an InSb photodiode 1850–5650 cm-1, to simultaneously record solar intensity throughout mid-infrared. These have been used retrieve concentrations large number gases, including chlorofluorocarbons, NOy species, O3, ozone-depleting gases. We demonstrate how residual continua spectra, obtained after accounting absorbing can be obtain information about aerosols. extinction are calculated range modeled aerosol size distributions compositions with Mie theory fitted measured By varying distribution parameters sulfate weight percent, microphysical that best fit observations. effective radius is found between 0.4 0.6 μm, consistent derived instruments this post-Pinatubo period. parts spectral constrain possible values parameter show broad bandpass presents great advantage retrieval both composition over more limited range. provides 70–75% sulfuric acid solution, good agreement thermodynamic considerations.