I’ve designed data acquisition systems. It’s best to have a pre-amp right next to the sensor, and as short a run from the pre-amp to the analog to digital converter as possible. But these circuits generate heat… So I guess the designers chose not to amplify or digitize in the sensor box, instead buying a very expensive cable to run the unamplified analog signal as far as possible – which in many places isn’t far enough to get from the building to a good location.

But why does that short cable have to run to a building? For probably less than they spent on a cable, you could amplify and digitize the signal in a second box a few feet away, and send the numbers out on ethernet or RS-485. With either one of those digital connections, the basic circuit is over 100 feet, and there are repeaters, extenders, and modems that can send it an unlimited distance. If you insist on putting the recording computer in your office in the middle of miles of pavement, the sensors could be in a forest 10 miles away; all that’s needed is a phone line or wireless connection. Or budget for an internet connection and read the temperature in Sri Lanka from Houston.

My suspicion is that some boneheaded bureaucrat (or climate scientist without a clue about electrical engineering) restricted the engineers to one outdoors box. I’ve encountered such arbitrary restrictions in work for corporations, but government projects are much worse.

And now they beg the question of why they can’t buy a better cable. Seriously are there no cables that can be designed that don’t have these problems over 100m? We’ve been making cables for over a 100 years, surely we’ve licked these problems by now. Hell the don’t even have to solve the problem, just account for it.

On hot summer days, the firefighting crews at Albany International Airport use sensors to find out just how hot the runways and aprons become. That, airport spokesman Doug Myers tells us, is to let the emergency workers calculate what the “flash point” of spilled fuel would be.
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Perhaps it’s no surprise that the airport surfaces absorbed a lot of heat today. When firefighter Robert Scanlon measured it, the tarmac registered 192 degrees Fahrenheit, just 20 degrees short of the boiling point of water..
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On previous hot summer days, airlines often had to “bump” a few passengers and some cargo so that they could get airborne. Hot air has less lift than cold air, so a fully loaded passenger plane, especially one with a long flight ahead, would take more runway to get into the air on hot days. Now that the airport runways have been lengthened, however, that’s no longer a problem. Myers said he wasn’t aware of any flights having to lighten their load.

http://blog.timesunion.com/business/tarmac-at-albany-international-airport-hits-192-degrees/20562/

They also claim that siting doesn’t matter because somehow asphalt and concrete warm just as much due to a change in radiation etc as does grass and soil. Sounds unlikely to me.

What seems to happen is that they adjust the good sites to be just as bad as the bad sites so there is little difference between them.

Here are NOAA’s own admission of adjustments made to raw temperatures.

Notice the 5 ° F added to the most recent temperatures.

Equipment changes should all balance out but UHI adjustments should all be DOWN and more down in later years so the curve is upside down.

http://cdiac.ornl.gov/epubs/ndp/ushcn/ts.ushcn_anom25_diffs_urb-raw_pg.gif

But please, a reminder for the kajillionth time WATTS with an S

Also, Steve Goddard does posts on sea ice, not stations.

Thank you for your consideration.

Anthony Watts