Any thoughts on the correction the Hadley Centre had recently done on the presentation of their monthly temperature data because 2008 was turning out to be too cold to be true?
Also, I've never found a proper publication for this, but Hans Erren (a renowned / infamous climate sceptic, and ex-geophysicist) put up data suggesting that annual temperature increase is more relying on increase in winter temperatures than on increasing summer temperatures. Which, if so, the first cold quarter would make the mean T of 2008 indeed a relatively cool year.
From his website:
With the current La Niña predicted to stay around for at least 3 more months, 2008 is shaping up to be a downward blip.
During a warming period winters change faster in the Temperate regions, because with the lower temperature gradient between Poles and Tropics there's less cold polar air coming towards lower latitudes. Also, the snow cover diminishes. Vencit omnia veritas.
UC observed a couple of days ago that Hadley Center, authors of the pre-eminent temperature series, have suddenly identified an "error" in how they presented temperature data. For presentation of their smoothed temperature series in a part-year situation, their methodology calculated the average of months then available and used that to estimate the current year's temperature for presentation purposes.
For their influential graphic showing smoothed temperature series, they used a 21-point binomial filter (this is reported) extrapolating the latest number for 10 years.
This obviously places a lot of leverage on January and February temperatures. (UC has replicated their smoothing method; he sent me code and I've confirmed that we can exactly replicate their smoothing methods.)
For what it's worth, here is the original source. *Traitor*, n. A benighted individual who perceives an illusory distinction between serving his nation and abetting the criminals who govern it.
This gentle downward trend since 2002 is not present in the Northern Hemisphere data. So I don't think the seasonal variations mask the error that much.
But this malpractice is not that shocking to me. We have to look at longer time series to have a real sense of these things. Vencit omnia veritas.
I don't follow you. How does a multi-year gentle trend negate the (partial, statistical) masking of more rapid seasonal variation? *Traitor*, n. A benighted individual who perceives an illusory distinction between serving his nation and abetting the criminals who govern it.
But the basic point is that if you have a monthly weather data time series you know there is a 12-month cycle in the data that needs to be extracted especially if you're trying to construct a yearly time series. When the capital development of a country becomes a by-product of the activities of a casino, the job is likely to be ill-done. — John M. Keynes
