The information content of aerosol properties is discussed for a set of extinction coefficient measurements of the ILAS (Improved Limb Atmospheric Spectrometer) instrument. ILAS was launched on the ADEOS (Advanced Earth Observing Satellite) spacecraft in 1996 and has a wide spectral coverage in the infrared region (between 6.21 and 11.77 μm). From these extinction measurements, ILAS has a capability to provide the vertical profiles of gaseous species, which are important for studies of the ozone hole phenomena, as well as the stratospheric aerosol compositions. In this paper, we describe an algorithm to infer the chemical composition of aerosols, i.e., types of PSCs (polar stratospheric clouds), the size distributions, total volume and total surface areas of aerosols by using five window channels, i.e. one at visible waveleugth(0.78μm) and four (7.12. 8.27, 10.60. 11.76μm) at infrared wavelengths. Our algorithm mainly consists of two parts. The first part is to determine the chemical composition of PSCs and eulfate aerosols. The second one is to derive the mean size, volume and surface area. The main purposes of this paper are to provide the extinction spectrum over the whole infrared channels in order to estimate the reliable amounts of trace gases and also to estimate the information of aerosol surface distribution for heterogeneous chemical reaction studies on PSCs.
All Science Journal Classification (ASJC) codes
- Aerospace Engineering
- Space and Planetary Science