The argument is fairly technical and not the sort of thing that gets the average person as worked up as, say, the emerging steroid scandal in professional baseball.

For warming skeptics, however, the tropospheric data are the climate science World Series. They meet every challenge to the data with a furious counterassault, but the latest such challenge puts the skeptics down three games to one.

The groundbreaking work on the subject was done last year by a team at the University of Alabama-Huntsville, led by climatologist John Christy and principal senior scientist Roy Spencer.

The UAH team studied satellite data and found the troposphere, which extends up to an altitude of about 7.5 miles - and where most of the planet's weather occurs - was not warming as fast as the surface.

This finding conflicted with climate models, which predicted the two should be warming at more or less the same rate. The discrepancy dealt a potentially serious blow to the contention that Earth's climate is experiencing a warming that is greater than historic variation.

The satellite data set has been reviewed three times by researchers outside UAH, the first two of which failed to resolve the discrepancy. The latest, however, seems to show the troposphere is, in fact, warming at the rate predicted by the computer climate models.

In a paper to be published in the Dec. 15 issue of the Journal of Climate, Qiang Fu, a climate professor at the University of Washington in Seattle, has re-examined his own earlier work - published last May in the British journal Nature - that after subtracting a cooling signal from the stratosphere from the tropospheric data, the results closely coincide with the climate models.

We used three different data profiles, three different data sets, Fu told UPI's Climate. You would expect that the exact results would depend on the detailed structure, but it's not sensitive to the structure. The difference is very small. That's the beautiful part.

Fu used data from National Oceanic and Atmospheric Administration and from Britain's Hadley Center for Climate Prediction and Research. The results he obtained got from the different processes he used almost exactly the match the work he did in the May Nature piece, providing essentially an independent confirmation of that work.

These results are consistent with the results that the Nature paper gets, Fu said. It is an independent check of the problem because we used completely independent data sets. The independent observations agree with our conclusions, and that's quite powerful evidence.

Microwave sounding units on the National Oceanic and Atmospheric Administration's polar-orbiting satellites measure heat radiation emitted at different frequencies, which can provide data for the different layers of the atmosphere.

A well-known greenhouse effect is the cooling of the stratosphere - the upper portion of the atmosphere - and some of the signal from this cooling contaminates the temperature record the NOAA satellites compile from the troposphere.

Fu and his colleagues, in their new round of work, measured stratospheric cooling directly, then subtracted the data from the tropospheric record to arrive at their conclusions.

The work finds a tropospheric warming of about two-tenths of a degree Celsius per decade. This is very close to the warming projected by climate models. The UAH team also found a tropospheric warming trend, but it was only 0.08 degrees C.

One criticism of Fu's work is it is a statistical result, rather than a physical one.

The bottom line is that their technique results in certain errors that they think cancel out, UAH's Roy Spencer told Climate, but we don't think there is enough information on stratospheric trends to know whether those errors cancel out.

Spencer and Christy criticized Fu's initial work because they said they had used his technique and it did not work. The criticism was published primarily on the Internet, not in peer-reviewed journals, but it did inspire Fu to reconsider his research and conduct this current effort.

I didn't know Spencer before this, Fu said, but now I've met him at some scientific conferences, and we can talk about the science. At the time, he was so sure we were damn wrong ... Now he says we don't know enough.

Kevin Trenberth, head of the climate analysis section of the National Center for Atmospheric Research in Boulder, told Climate: Some people won't like their data because (they are) statistical rather than physical.

I'm sure it won't be the last word. They qualify a bit better how well they remove the stratospheric influence. The remaining residual error is one-hundredth of a degree Kelvin per decade.

The lower troposphere record of of Spencer and Christy has more problems and has contamination from the stratosphere.

Christy countered, however, that his team's work corresponds more closely with physical measurements taken from weather balloons and other physical measurements of the troposphere taken around the world.

The Fu work tries to infer tropospheric temperatures based on the differences of stratospheric temperatures. Those are the temperatures we have the least confidence in, Christy told Climate.

The satellite data are broad functions, so by subtracting the stratospheric portions and trying to tease out the tropospheric data that incurs a lot of error ... There's a better way to do that - by directly measuring the troposphere.

In a written response to the new Fu paper, Spencer said the data from the from the upper troposphere, on which Fu relied, are lower quality trend information.

Nonetheless, he wrote, "Given the much greater influence of the upper troposphere on the Fu et al. weighting function ... the two estimates are really not inconsistent with each other Thus the claims in their press release regarding the Journal of Climate paper were, in my view, exaggerated."

An exchange in last week's Nature offered some for both sides. Three researchers, led by Nathan Gillett of the University of Victoria, British Columbia, found the analysis of Fu et al. is robust and ... in good agreement with those independently derived from climate models.

At the same time, however, Simon Tett and Peter Thorne from the Hadley Center argued that Fu's approach overfits the data, produces trends that overestimate warming and gives overly optimistic uncertainty estimates.

One strength of Fu's research is the data do explain variations of temperatures that are observed and expected by models in the tropics.

All of the discrepancies that have been highlighted by skeptics with regard to the models disappear, Trenberth said, adding I'm sure it will not put everything to rest, and there will be other disagreements and reasons for finding problems with it.

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