Concept for the remote sounding measurement of the atmospheric carbon dioxide column from space

Concern about the climatic effects of anthropogenic emissions of carbon dioxide has resulted in a growing need, both scientifically and politically, to monitor atmospheric carbon dioxide. The development of a satellite instrument which could measure the global distribution of atmospheric carbon dioxide would greatly improve our understanding of the global carbon cycle and provide a means of monitoring regional sources and sinks. In this paper, we propose and analyze the potential of a nadir-viewing, satellite-based remote sounding instrument consisting of a simple filter radiometer tuned to the 6300 cm-1 (1.6 micrometers ) region to globally measure the atmospheric carbon dioxide column. Such an instrument would be among the simplest of all potential remote sounding instruments to make this measurement. Retrievals by a radiometer instrument are modeled using high-resolution FTS spectra and compared with SFIT2 retrievals. We find that the proposed instrument has potential, and that the sensitivity is likely to be limited by our knowledge of the atmospheric temperature and uncertainty line strengths and widths.