Combinations of different channels of individual Microwave Sounding Unit (“MSU”) measurements have been used to generate a record of estimated atmospheric temperature change back to 1979, the “MSU Temperature Record”. The complex vertical weighting functions relating the the various channels of the MSU to atmospheric temperatures complicate the interpretation of the MSU data. Moreover, while MSU measurements are available back to 1979, a single, continuous long record does not exist. Rather, measurements from different satellites have been combined to yield a single long record, further complicating the interpretation of the MSU record. Direct comparisons of the MSU Temperature Record with the surface temperature record are therefore difficult. More information on the MSU Temperature Record can be found here.
Is there any new news regarding the attempts to resolve the discrepancy between different groups’ analyses of the temperature trends from the satellite data? I tend to tell people that the papers that came out in the last couple of years changed the question back from “Why do the satellite and surface measurements disagree?” to “Do the satellite and surface measurements disagree?”
But, I’ve been wondering if there has been any sort of resolution on this latter question?
[I know that technically “disagree” is a bit of an oversimplification and that a more precise statement of the question might be something like “Do the satellite measurements of the troposphere show a smaller mean temperature rise than the surface measurements, whereas the models predict that anthropogenic warming should result in a somewhat larger temperature rise in mean tropospheric temperatures than at the surface?” But that all gets to be a good deal less pithy!]
[Response: Thanks for your comment. We hope to have a more detailed posting on this sometime in the future (perhaps a FAQ item on “Is There Any Inconsistency Between Different Instrument-Based Measurements of Atmospheric Temperature Trends”). Meanwhile, you can find decent, up-to-date discussions on Wikipedia and in the recent National Academy of Sciences report on “Radiative Forcing of Climate Change: Expanding the Concept and Addressing Uncertainties (2005)” (see specifically the discussion on page 62 and pages 101-102″ of the report). -mike]