Sensitivity studies for space-based measurement of atmospheric total column carbon dioxide by reflected sunlight

摘要

The feasibility of making space-based carbon dioxide (CO_(2)) measurements for global and regional carbon-cycle studies is explored. With the proposed detection method, we use absorption of reflected sunlight near 1.58 μm. The results indicate that the small (～1%) changes in CO_(2) near the Earth's surface are detectable provided that an adequate sensor signal-to-noise ratio and spectral resolution are achievable. Modification of the sunlight path by scattering of aerosols and cirrus clouds could, however, lead to systematic errors in the CO_(2) column retrieval; therefore ancillary aerosol and cloud data are important to reduce errors. Precise measurement of surface pressure and good knowledge of the atmospheric temperature profile are also required.