Friday, May 29, 2009
Iowans can't measure the temperature
Belle Plaine and Toledo are 18 miles apart with only 30 ft difference in elevation. The daily temperatures vary by as much as 20 degrees, and does so far more often than would be expected by cold fronts being between the cities. The red curve is a 365-day running average of the difference between the average daily temperatures. That curve for decades was over 2 deg F , with Belle Plaine hotter. If this temperature
difference was real, it should have led to decades long thunderstorms and winds. Noted the sudden onset of bad data in about 1964 I thought it might be a station move, but the station record doesn't show it moving then. It stopped again in 1998, although the noise didn't go back to 1950s levels.
The small green line in 1965 is 100 years of global warming. Clearly the noise for one year is greater than that. There is no way we can nudge global warming out of signal this bad.
Here is why. When you make a measurement of anything, and you decide to adjust it for an error, you are saying that the error in the raw measurement is the value of your adjustment. That becomes the error bar. Consider this from a site dedicated to explaining error analysis.
The accuracy of a measurement is how close the measurement is to the true value of the quantity being measured. The accuracy of measurements is often reduced by systematic errors, which are difficult to detect even for experienced research workers.Source
Now that was a statement about linear systematic errors. What we have in the temperature stream is nonlinear systematic error. If you make a 2 deg correction for this period of time, you can't claim that the accuracy of the data is less than 2 degrees. This has profound implications
Over the past century global warming is said to have warmed the world by 1.1 deg F, yet they are making corrections of +/-2 degrees to the data stream. That means then that one can't possibly, say that the world has warmed by 1.1 deg F. Statistically it is lunacy to say that the world has warmed by 1.1 +/- 2 degrees, which means it might have cooled by 1 degree or it might have warmed by 3 degrees. The data doesn't allow us to tell.
Before I make the final comment, I want to let everyone know that the data for the chart above came from Dave's favorite site.here. It is a government site.
One final thing, in the comments some have criticized me for using CO2science previously as a source for my yearly data. I compared CO2 science, which is raw with the final edited data for Belle Plaine. You can see below that the differences are minor and thus the criticism is simply that of people stretching to find anything wrong with what I am saying. What am I saying? The data is crap.