Spectroscopic observations of CO2 CH4 N2O and CO from Kitt Peak 1979-1990

摘要

Abstract: A program for the observations of the sun in the 1.0 - 3.5 $mu@m region using the 1-m FTS was sponsored by the Battelle Foundation from 1979 to 1985. The objective was to monitor anthropogenic change of atmospheric trace gases represented in this spectrum interval. Those observations have been resumed at a monthly cadence, or as resources allow. Earlier data has been combined with the new and reanalyzed data in a self-consistent way. The spectroscopic method yields total column amount. Where simultaneous ground-level gas-sampling data was obtained, the results were comparable but the gas-sampling technique yielded a scatter about 4 times less (for CO$-2$/). Attempts are being made to improve the precision of the FTS determinations by making repeated observations, by using O$-2$/ lines strength to deduce effective air mass where appropriate, and by careful attention to line blends in the spectral analysis. For 1979 to 1990, CO$-2$/ shows an increase of 0.4%/yr, for CH$-4$/ 1.1%/yr, which is a slight decrease from the 1979-85 interval. N$-2$/O shows no trend within an upper limit of 1 ppb/yr. The behavior of CO is dominated by a large seasonal variation and no reliable trend can be concluded. The strengths and weaknesses of the FTS and grating spectrometer are compared.!