Over at The Resilient Earth, Doug Hoffman has a post up exposing a severe problem for climate science. The computer models of the climate system, the GCM’s, are designed, parameterized and tuned to match the data we have for the historical temperatures observed both at the surface, and at various altitudes as measured by thermometers, radiosonde balloons, and satellite data.
For many years the theory of Anthropogenic Global Warming, AGW, has been predicated on the premise that the cooling in the stratosphere is an indication that extra co2 is ‘trapping’ extra heat in the troposphere, leading to a warming of the surface. But there’s a problem.
The MET office dataset derived from the SSU (Stratospheric Sounding Unit) instrumental raw data is undocumented. The NOAA started analysing the same raw data in 2009, and have produced their own fully documented dataset which shows radically different results, especially in the mid stratosphere from 15 to 35km above the surface of Earth. In this region, the divergence between the datasets is up to 2C or 2K, the MET Office data being warmer. The divergence between the datasets starts before the eruption of Mt Pinatubo in 1991. Whereas the MET Office dataset shows a fairly level temperature, the NOAA analysis shows a downtrend. Post Pinatubo, the MET Office shows a much higher temperature than the NOAA and a slight uptrend from then to the present. The NOAA data shows a much lower temperature and a downtrend.
The differences are striking, to say the least.
In his article, Doug Hoffman doesn’t go very far into what this means for the AGW theory, saying that:
One of the predictions made by climate models is that as surface temperatures rise[,] temperatures in the stratosphere should drop. Precisely why this should be so is complex and not important to the point being made here. Suffice it to say, the Met Office version of the SSU data suggests that the models overestimate the observed stratospheric cooling, whereas the NOAA SSU data suggest that the models underestimate it.
At first flush, it might seem that this might provide an opportunity for the proponents of the AGW theory to jump up and shout from the rooftops:
It’s worse than we thought!
But here at the Talkshop, we know better than to jump to conclusions. The magnitude of the temperature drop in the stratosphere shown by the NOAA dataset might suggest that the changes have actually been driven from the ‘top down’ by the Sun rather than the ‘bottom up’ by the increase in CO2. This notion is supported by NASA’s discovery that since the Sun went quiet in 2004, the thermosphere, higher up than the Stratosphere, has shrunk by nearly a third. More recently, NASA discovered that the average height of the cloud deck below the stratosphere in the troposphere has fallen by 40m or so since 2001. Meanwhile, CO2 levels have continued to increase in a fairly linear way.
Given the other recent controversy the MET Office has recently been involved in and the information from Richard Betts of the MET O that the new forecast uses a new model, HADgem3, the question I’ve asked Richard Betts on twitter is this:
— Rog Tallbloke (@rogtallbloke) January 17, 2013
No reply yet.
I’ll leave the last word to Doug Hoffman and Thompson et al:
According to the Nature article: “The differences between the NOAA and Met Office global-mean time series shown in Fig. 1 are so large they call into question our fundamental understanding of observed temperature trends in the middle and upper stratosphere.”
How did the Met Office get their data so wrong? Well there’s the rub. You see, the methodology used to develop the Met Office SSU product was never published in the peer-reviewed literature, and certain aspects of the original processing “remain unknown.” Evidently the boffins at the Met didn’t bother to write down exactly how they were massaging the raw data to get the results they reported. Indeed, those who did the data manipulation seem to have mostly retired.
The mystery of recent stratospheric temperature trends
David W. J. Thompson et al
Nature 491, 692–697 (29 November 2012) doi:10.1038/nature11579
A puzzling collapse of Earth’s upper atmosphere
NASA Satellite Finds Earth’s Clouds are Getting Lower