I was riding my bicycle home after picking up sushi for the kids, and it all became clear. The purpose of the USHCN adjustments is to hide the UHI effects in the GHCN data set.
More than half of the GHCN US stations are at airports – and are no doubt strongly affected by UHI effects. Thus the strong warming trend in the GHCN US daily data, which is not seen in the USHCN daily data.
In order to make the USHCN data match the UHI tainted GHCN data, they had to implement some huge bogus upwards USHCN adjustments.
The honest thing would have been to downwards adjust the GHCN data for UHI, but that just isn’t how climate science works.
Any idea why there’s a huge step change in the first plot around 1950? Airports change considerably in the late 1940s?
-Scott
The number of stations doubled between 1946 and 1950
And that causes some sort of large upward shift in the anomaly?
-Scott
They probably added a bunch of hot airports.
Lots of airports would have switched from being grass to concrete/tarmac with the introduction of jets.
I know he’s using different data sets but IMO Chiefio’s analysis is relevant and worthy at
http://chiefio.wordpress.com/2012/07/27/more-airports-hotter-than-nearby-stations/
In the Washington, DC area, two airports became major weather stations. BWI (Baltimore Washington International) did so around 1950 and Dulles around 1963. They both were out in the “sticks” when they first came into being. Now they are part of suburban sprawl, with much more development in the surrounding area. Isn’t it quite obvious that if you are going to do any adjusting that the more recent years should be adjusted down and earlier years up. It would appear that Hansen and Company are doing just the opposite.
Dulles was probably the biggest slab of concete in Christendom when it was built in the woods in Virginia – no UHI there!
I can’t decide which is more incredible, the temperature nonsense, or kids that eat sushi.
Huh?
Sorry about the late comment. Just catching up on my essential blog reading after being away for a holiday. What struck me with you article, was that as a skeptic, you rode your bike to the shops! You didn’t take your car. I’ve heard that some rich actor who considers himself an environmentalist, takes his helicopter up the coast for breakfast. Hypocrisy.
I never get in a car unless I have no other choice.
Weather instruments and their specific site locations at airports are very valuable and depended upon by almost countless multitudes. These airport situated weather stations are deployed to schedule and manage air traffic(landing/takeoff/stacking/routing). Dual utilization of these airport weather instruments for the immature and highly-speculative field of climate ‘science’ should have raised red flags and halts in funding years ago. -Paul in Sweden