Measurements of spectrally resolved outgoing longwave radiation allows signatures of many aspects of greenhouse warming to be distinguished without the need to amalgamate information from multiple measurements, allowing direct interpretation of the error characteristics. Here, data from three instruments measuring the spectrally resolved outgoing longwave radiation from satellites orbiting in 1970, 1997 and 2003 are compared. The data are calibrated to remove the effects of differing resolutions and fields of view so that a direct comparison can be made. Comparisons are made of the average spectrum of clear sky outgoing longwave radiation over the oceans in the months of April, May and June. Difference spectra are compared to simulations created using the known changes in greenhouse gases such as CH₄, CO₂ and O₃ over the time period. This provides direct evidence for significant changes in the greenhouse gases over the last 34 years, consistent with concerns over the changes in radiative forcing of the climate.

Date Published: 4 November 2004
PDF: 11 pages
Proc. SPIE 5543, Infrared Spaceborne Remote Sensing XII, (4 November 2004); doi: 10.1117/12.556803

Published in SPIE Proceedings Vol. 5543:
Infrared Spaceborne Remote Sensing XII
Marija Strojnik, Editor(s)