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Found: the hot spot? Not

Posted By Joanne Nova On October 30, 2008 @ 1:37 am In Global Warming | Comments Disabled

The gap between real world data and thermometers is a make-or-break issue for the AGW theory. The models predict a hot-spot in the atmosphere above the tropics, but the weather balloons (called radiosondes) can’t find any sign of it. Most claims that the hot-spot has been found are not providing any new data, they are just massaging the same old numbers with a different statistical tool. Here are three variations (though the third is not a statistical-spin, it’s just nonsense).

1-Some AGW supporters claim that Santer et al has found the hot-spot. But his paper boils downs to a statistical reanalysis that suggests that due to noise and error, the hot-spot might be there. Santer hasn’t actually found the missing hot spot. He has a case, but it’s not a strong one. The statistical counterargument is at Climate Audit.

Even if Santer is right and the hot spot IS hidden in the noise, the most generous interpretation is that greenhouse gases must have a pretty weak warming effect…

2-Sherwood (another co-author of the Santer paper) published research suggesting that the hot spot is there – but he threw away the temperatures from weather balloons and used wind-shear measurements with mathematical analysis.

Because of the importance of this point, investigators have left no statistical stone unturned in their quest to find the hot spot. According to the Sherwood paper those same old radiosonde results going back to 1970 have been subject to “…statistical procedures, station metadata, various indicators of natural variability (such as volcanic eruptions, vertical coherence) and forecasts from a climate data assimilation system.” In their own words:

“Despite these attempts, most analyses of radiosondes continue to show less warming of the tropical troposphere since 1979 than reported at the surface.”
Allan & Sherwood. “Warming Maximum in the Tropical upper troposphere deduced from thermal winds”

Here Sherwood admits that despite an extensive all-out effort, almost every way you look at it with thermometers and statistics they just can’t find the results that the climate models predict. So he resorts to wind-shear. You have to award points for creative effort.

Crikey. The money we wasted putting thermometers on weather balloons…

3-Tim Lambert has a go at asserting that the hot spot has been found. But he confused himself with nice graphs and faulty reasoning. He shows a graph of the fingerprint of warming induced by CO2 next to the fingerprint of warming induced by solar irradiance. Both show a warm spot above the tropics. And what do you know? There’s no evidence that either fingerprint is occurring. (Tim, how is this supposed to prove the hot spot has been found?) Then he points to the cold bar at the top of the CO2 graph, keeps a straight face and suggests that because the weather balloons found some cooling here, that means that the hot spot is not missing. Hmm. So if you are a warmist, half a fingerprint counts as proof, even if it’s the cold half, and you’re trying to prove a warming event.

How are greenhouse gases supposed to heat the planet if they don’t warm some air somewhere? Cooling the upper atmosphere makes for a lousy heat pump.

A fingerprint is a not a fingerprint if half the pattern is wrong. And besides, if Tim looked further he’d note that other causes of global warming also cool the upper atmosphere, like ozone depletion.


The old radiosonde data is what it is. We can’t go back in time and measure where warming occurs until warming occurs again, which hasn’t happened since 2001. So we’re left just with what we have, which plainly does not show a hot spot. Measuring the temperature 10,000m up is not simple—witness all the compensatory factors researchers are working with just to take the air temperature: time of day, season, wind strength, equipment changes, and station relocation. Given how complicated this is, it boggles the brain to imagine the complexities involved in modelling the global climate.

If we can’t be sure we’re measuring the temperature correctly, what chance do we have to measure and manipulate cloud cover, air movements, rainfall, humidity, turbulence, surface reflectivity, AND temperature?

The world is not getting warmer unless you measure ground temperatures in car parks, or tropospheric temperatures with wind gauges. Clutching at straws anyone?

In the absence of better information, based on what we have, the simplest explanation is that greenhouse gases are not warming up the planet significantly.

See all posts tagged “Missing Hot Spot”

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