Saturday, September 5, 2009

The Anatomy of Biased temperatures

I always want to start out by pointing out that two closeby towns should, by all considerations, have very similar temperature records. But, as I have found over the past few months, this is not the case. I am taking a second look at Columbus and Seymour, Indiana tonight. Tonight I am looking in detail at the bias between the two towns.

Below is a chart of the temperature difference between Columbus and Seymour (Columbus minus Seymour) for the years 1992-1994.



You can see both wild differences in temperature between the two towns, but you can also see that for the 3 years shown here, in general, Columbus is much hotter than Seymour--by 3 degrees.

Let's look at 1992-1993.



You can see that in the winter of 1992-1993 the bias decreased a bit and then rose again in the spring.

1992 looks like this:



Now, all the above biases are positive. During 1971-1972 the bias was the other direction.



One sees a long stretch of negative biases from 1958 to 1964. Such things do not give great confidence that the temperature is being measured properly.

2 comments:

  1. I can't believe it's been so long since I looked you up. You have a blog now! I use your home.etouch.net/dmd page as a reference somewhat regularly.

    We exchanged some emails years ago. I'm working on my own web site at the moment, linking to your story and your Pathway Papers, which I hope are being used by many people. Can't wait to read through your blog posts, though it will probably have to wait for tomorrow.

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  2. Hi Shammah, Thanks for the kind words. The Pathway Papers were a failure, but that is ok, a life is filled with more failure than success, at least for most people.

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