REMOTE-SENSING OF CO, CH4, AND O-3 USING A SPACEBORNE NADIR-VIEWING INTERFEROMETER

Within the next 5 years, several instruments launched on polar orbitin g satellites will provide high-resolution infrared remote-sensing meas urements of CO, CH4, and O-3 on a global scale. The upwelling spectral radiances to be recorded by a nadir-looking remote sensor have been s imulated using a high-resolution radiative code (line-by-line radiativ e transfer model (LBLRTM)) coupled to a three-dimensional chemical tra nsport model (intermediate model of the annual and global evolution of species (IMAGES)). The instrumental specifications of the Fourier tra nsform interferometric monitor for greenhouse gases/Advanced Earth Obs erving System (IMG/ADEOS) and infrared atmospheric sounding interferom eter ( IASI/METOP) were used to generate realistic data. Calculations have been performed to assess the sensitivity of the nadir spectral ra diances to changes in the gas concentration, temperature profile and t o instrumental characteristics. We provide spectral intervals for an e fficient retrieval of these species, together with a set of climatolog ical tropospheric standard mixing ratio profiles.