Global warming: Evidence from satellite observationsThe second of two MSU analysis products from a team lead by Prabhakara of NASA. This analysis is similar to the RSS products, except that their merge analysis assumed a constant temperature calibration (based on an onboard “hot target” at a known temperature). The UAH and RSS teams both derived corrections for each satellite in the series as part of their merge calculations. The trends in this paper agree well with the comparable RSS trends, but not with those of UAH Version D to which they are most comparable.

Global Warming Trend of Mean Tropospheric Temperature Observed by SatellitesThe paper by Vinnikov & Grody presenting their MSU derived upper-air retrieval and analysis, which was based on a unique statistical method to merge the different satellite records. Vinnikov and Grody’s method is very different than that of the other teams. It is based on certain assumptions about daily, annual, and interannual cycles in atmospheric temperature that, if valid, will yield the most accurate and noise-free results of any of the extant analysis products. However, if these assumptions differ significantly from the actual temperature cycles they simulate, considerable error might result. This product yields the highest warming trends of the currently published MSU analyses, and has received less attention than the UAH and RSS products.

The Effect of Diurnal Correction on Satellite-Derived Lower Tropospheric TemperatureThis is the August 2005 paper first published online at Science Express (subscription required for full text) in which Carl Mears and Frank Wentz of RSS present their discovery that UAH MSU products had been applying corrections to the MSU data from the NOAA-11 satellite in the wrong direction, thereby introducing a spurious cooling into UAH analyses. When the error was corrected, beginning with UAH Version 5.1 (Christy et al, 2005) this record’s disagreement with extant climate model predictions of global warming all but vanished and with it the only potentially credible argument global warming skeptics ever had. The NOAA TIROS Series of satellites that carry the MSU packages are in polar orbits that are sun-synchronous (i.e.—in orbits that preserve their orbital plane with respect to the sun throughout the year so that they rise and set in the sky at the same time on any given day and location during their service lives). Imperfections in this sun/satellite synchronicity cause a drift in the satellite’s daily rising and setting times during its life that will appear to the sensor as a spurious warming or cooling depending on the direction (it’s usually much cooler at 6 AM than it is at noon!). This is referred to as diurnal drift. NOAA-11 had a comparatively large one—enough so that reversing the correction for it was enough to spuriously remove most of the warming that should have been present in UAH products.

Correcting the MSU Middle Tropospheric Temperature for Diurnal DriftsThis 2002 paper from the RSS team describes the issues involved in correcting remotely sensed temperature data from satellites for diurnal drift (variations in the sun-synchronicity of polar orbits) and the methods used to correct their MSU datasets. The UAH team relies on a different method based on comparisons of the MSU sensors’ side-looking views—that is, at angles to the left and right of nadir (straight down) along its flight path.