An example of how temperature measurements can be inaccurate?

Question

Marysville, CA

Picture of "temperature station"

http://gallery.surfacestations.org/main.php?g2_itemId=831

And its Charted temperature measurements.

http://gallery.surfacestations.org/main.php?g2_itemId=901

55 miles away, less than 200 feet difference in elevation.

Orland, CA "temperature station"

http://gallery.surfacestations.org/main.php?g2_itemId=569

And the charted temperature measurements here.

http://gallery.surfacestations.org/main.php?g2_itemId=31243

Now, why would there be such a difference in the temperature readings of two temperature stations only 55 miles apart?

Answer 1

With hundreds of stations, you can find some isolated ones that show anything you want.  Simple statistics.

The fact is that Watts has given his dog and pony show to climatologists.  They're not buying it.  Because they have looked at ALL the data, and find it accurate.  One study of many:

"Climate:  Large-scale warming is not urban", David E. Parker, Nature 432, 290 (18 November 2004)

Note that Watts has no publications.  That giant conspiracy?  Or bad work?

So, are the climatologists stupid, ignorant, or engaged in a giant conspiracy?  Or does Watts (who is simply a weatherman) not know what he's talking about?

Easy call for me.

Answer 2

Surface Stations is a perfect example of denialism in action. Those two pictures (conveniently located on the front page of the site) are obviously meant to imply that the 20th century warming trend is a result of the UHI effect (despite the fact that the scientists constructing the temperature record take great pains to remove biases like UHI from the record). Notice how the "good" station shows a cooling trend, while the "bad"  station shows a clear upward trend.

I have no problem with a genuinely honest attempt to scientifically audit the US surface stations, but this isn't it. Surface Stations is nothing more than a despicably dishonest attempt to discredit the surface temperature record. Snapping a couple photos of a station doesn't tell you anything about the station's history, or what sorts of biases and errors the data might contain.

Answer 3

yes that's why most temperature reconstructions control for errors such as this. for example by using more then one station and  spacing these out.

Answer 4

Is this a sincere question?  Do you honestly want to know why?  Because you're not going to like the answer.

"Something is odd here. The Orland plot starts just after 1880, but the Marysville plot starts after 1900. Also, the y-axis on the Orland plot has a range of 6 deg.C while the y-axis on the Marysville plot only covers 5 deg.C; when comparing the graphs, that would tend to exaggerate the Marysville trend relative to Orland.

NASA GISS station data are available for download, so I retrieved the data for Orland and Marysville, CA. Since GISS corrects for identifiable biasing factors like station moves, instrument changes, time-of-observation bias, and yes, urban heating, I retrieved the corrected GISS data. From the raw monthly data, I computed yearly averages, keeping only those years that had data for all 12 months; plotting them together gives this:

http://tamino.files.wordpress.com/2007/0...

Suddenly the two stations don’t seem quite so different as the impression given by the graphs on surfacestations.org. Much of the different impression is due to the fact that the Orland data start decades before the Marysville data, when the Orland time series is cooling strongly. Also, GISS has corrected for known biasing factors. Lo and behold, all of a sudden the time series aren’t nearly so different!"

"Here’s a graph of the annual averages for complete years since 1975, together with trend lines fit to both data sets:

http://tamino.files.wordpress.com/2007/0...

"Not only are the graphs strikingly similar, the trend rates are nearly identical. Analyzing the monthly, rather than annual, data for greater precision, and accounting for the effect of autocorrelation, the indicated trends with their error ranges are:

Marysville: 3.77 +/- 1.88 deg.C/century

Orland: 4.06 +/- 1.98 deg.C/century

The trend rates are nearly the same! The difference between the computed trends is much smaller than the uncertainty in the calculations. So, for all intents and purposes, these two stations indicate the same trend during the modern global warming era.

Surfacestations.org calls the Orland station a “well-sited” station and Marysville a “not-so-well sited” station, and displays them prominently to give the impression that “good” data indicate cooling while “bad” data indicate warming. It’s ironic that when you look at the actual data, during the modern global warming era Orland indicates more warming than Marysville.

Imagine that."