OT: Human-caused warming likely led to recent streak of record-breaking temperatures: study

It's silly to think that 50 or 100 year old air temperature measurements can be compared to modern ones with degree-C accuracy. The old ones are usually "corrected" anyhow.

The satellite data is better, but we don't yet have enough data to separate out the low-frequency noise.

Yes. People used to read mercury thermometers with their eyeballs, once or twice a day, with unknown diligence.

I think it is just south of the Deer Valley airport - 19th ave or maybe 7th ave and probably Rose Garden. Rose Garden was the street north of my house. I think they built some parts of the space shuttle there.

Back in the day the DVT airport had a nice little cafe/bar with covered outside seating. Great place to have a beer and watch a moosoon thunderstorm. There was nothing between the airport and carefree hiway but open desert.

I remember it well... used to grab lunch there occasionally. ...Jim Thompson

Yep, it's in a lousy location. Also, plenty of potential of getting high temperature readings from jet exhaust if the wind is blowing in the right direction. Still, it's better than an airport rooftop, where it can measure the HVAC equipment output. The very high record temperatures might be due to jet exhaust, sensor error, or bad siting. Dunno.

Weather station siting is a PITA in urban areas. The basic problem is a tradeoff between minimizing outside influences and maintaining security. Putting the main weather station in the middle of an empty field is great for accuracy, but not so great if someone can just drive up and haul off the entire weather station. Finding a suitable and secure location in the middle of a huge heat island (Phoenix AZ) is difficult.

Agricultural weather networks are far better at siting their sensors, usually in flat open fields. For example, the California CIMIS network: Arizona may have something similar. Digging... This one should be nearby: The anemometer isn't high enough (should be about 10 meters high) but everything else looks acceptable.

NWS Proper Siting (which includes ASOS): "The sensor should be at least 100 feet from any paved or concrete surface". Right...

The other part of the puzzle is that these stations were never designed to have their data used for climate research, where accuracy and consistency are paramount. They're designed to give airport managers and pilots a good idea of the local conditions for determining takeoff speed and maybe provide some numbers for the local weather guessers. For these, a few degrees one way or other is good enough. When climate research became fashionable about 20 year ago, the airport ASOS system was drafted into service and the data crammed into various climate models. When the models became muddles, the data from all these inaccurate weather stations was averaged together on the assumption that the errors were random and would cancel each other. That's not the case as thermal heat islands always have a positive temperature bias. See the reader comments on the situation (2008):

The subject line is correct. Your record temperatures were caused by humans. In this case, by jet exhaust, bad siting, and sensor errors.

Actually, the current data is equally often tweaked to align with the old data. Ideally, what is measured is the temperature of the air. More commonly, it's the temperature of nearby IR reflectors or sources. It's amazingly difficult to obtain 1 degree air temperature accuracy. I thought I had it right, only to find that the heat from the small fan I was using to move the air was good for about +1C error. Of the naturally asperated radiation shields available, I don't trust any of them. This is from 1999, but still applicable: "Comparison of Five Radiation Shields"

They still do and manual weather stations are still produced: The logic is to maintain the consistence of the data by using exactly the same methods that were used in the last 100-200 years. Some agencies have a few such manual stations. The manual data is compared with the automated stations and used as a sanity check. Locally, the only accurate rainfall numbers I can find come from such a manual station.

More importantly, it's giving the wrong answers.

As if krw would know what the "right" answers might be. The Koch brothers w ill tell him what the far-right answers ought to be, but the motivation the re is to let the Koch brothers keep in making money out of the oil business .