Atmospheric CO2 retrieved from ground-based near IR solar spectra
نویسندگان
چکیده
[1] The column-averaged volume mixing ratio (VMR) of CO2 over Kitt Peak, Arizona, has been retrieved from high-resolution solar absorption spectra obtained with the Fourier transform spectrometer on the McMath telescope. Simultaneous column measurements of CO2 at 6300 cm 1 and O2 at 7900 cm 1 were ratioed to minimize systematic errors. These column ratios were then scaled by the mean O2 VMR (0.2095) to yield columnaveraged vmrs of CO2. These display similar behavior to the Mauna Loa in situ surface measurements. During the period 1977–1995, the column-averaged mixing ratio of CO2 increased at an average rate of 1.49 ± 0.04 ppmv/yr with seasonal variations of 7 ppmv peak-to-peak. Our retrievals demonstrate that this remote technique is capable of precisions better than 0.5%.
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