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| Tatsuya Yokota | |
| Program Research Manager, Center for Global Environmental Research | |
| National Institute for Environmental Studies, Ministry of the Environment | |
| 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 Japan | |
| Tel: +81-298-50-2550, Fax: +81-298-58-2645 | |
| E-mail: yoko@nies.go.jp |
43,295,000 Yen
(FY 2000; 14,460,000 Yen)
In order to retrieve profiles of greenhouse gases and minor constituents in the lower stratosphere and upper troposphere from solar occultation satellite sensors, sensitivity and error analyses were done by numerical simulation for Improved Limb Atmospheric Spectrometer-II (ILAS-II) and Solar Occultation FTS for Inclined-orbit Satellite (SOFIS). The following results were revealed. The retrieval precision on ILAS-II data around the altitude of 20 km will be improved five times for ozone and eight times for methane from that on ILAS data, because of the additional spectral information of shorter wavelengths in ILAS-II measurement. One of the major error sources for gas retrieval is temperature estimation. ILAS-II and SOFIS could provide mixing ratios of carbon dioxide and other gases in the upper troposphere with reasonable precisions and with no bias as long as pressure and temperature data are correctly introduced into the retrieval procedure. SOFIS would also detect CH4, N2O, PFC-14, and SF6 with reasonable precision. A new method of a micro-window selection for sensors with high spectral resolution has been developed with consideration of aerosol effects. A fast and simplified method of global inversion, which uses a multiple regression model and a principal component expansion has been developed for gas profile estimation directly from ILAS-II transmittance data and pressure & temperature profiles. Effectiveness of this method was confirmed by applying to the ILAS measurement data.
Stratosphere, Troposphere, Greenhouse gases, Data processing algorithm, Satellite data