Comparison of SCIAMACHY and AIRS CO2 measurements over North America during the summer and autumn of 2003

Atmospheric CO2 volume mixing ratios retrieved by the AIRS and SCIAMACHY instruments, are compared over North America during the summer and autumn of 2003. Examination of the deviations of the CO2 volume mixing ratios, relative to the mean CO2 background measured by each instrument, reveal large-scale coincidental spatial features that develop over the course of the year. Furthermore, the time series of the monthly CO2 anomalies show a seasonal cycle signal that is characteristic of the upper and lower troposphere to which AIRS and SCIAMACHY are respectively sensitive to. This comparison demonstrates that there is a general consistency between the CO2 distributions retrieved by AIRS and SCIAMACHY, when the different vertical sensitivities of the instruments are taken into account.