Temperature and pressure retrievals from O2 A-band absorption measurements made by ILAS : Retrieval algorithm and error analyses

A visible grating spectrometer of the Improved Limb Atmospheric Spectrometer (ILAS) aboard the Advanced Earth Observing Satellite (ADEOS) measured atmospheric absorption spectra at a wavelength region from 753 nm to 784 nm, including the molecular oxygen (O2) A-band centered at 762 nm, with a spectral resolution of 0.17 nm. Temperature and pressure profiles throughout the stratosphere were retrieved from the satellite solar occultation measurements of the O2 A-band absorption spectra. Based on simulation studies, root-sum-square errors associated with several systematic uncertainties in spectroscopic databases and instrument functions were estimated to be 4 K for temperature and 4% for pressure in the stratosphere. Current problems in this retrieval are also presented through comparisons with correlative temperature measurements.Takafumi Sugita, Tatsuya Yokota, Teruyuki Nakajima, Hideaki Nakajima, Katsunori Waragai, Makoto Suzuki, Akiyoshi Matsuzaki, Yasuhiro Itou, Hisaya Saeki and Yasuhiro Sasano, "Temperature and pressure retrievals from O2 A-band absorption measurements made by ILAS: retrieval algorithm and error analyses", Proc. SPIE 4150, 94 (2001)Optical remote sensing of the atmosphere and clouds II, Sendai, Japan, 9-12 October 200