Location Location Location

Well now we know, and I for one think it is worth the wait. Assuming this stands up to further scrutiny, and I have every confidence it will, this is a big deal.  These are only initial thoughts. Watts et al. 2012 confirms so much of what many of us have thought – that site, surroundings and equipment matter. Its provides a ‘we told you so’ moment for quality, attention to detail and due diligence. And, yes this may be US data only, but it pulls the rug from under the claims of runaway warming in the last two decades (hint – part of it is runway warming ;-)).

It is a surprise to see so many issues – Rural/Urban, Airports, ASOS/CRS/MMTS and adjustments, undermined together.

Running through the images on the Powerpoint file, the significance gradually sank in and with each new slide my excitement rose. First the highest quality raw stations have just over half the trend of all adjusted ones, then non-airport sites have half the trend of those at airports.

Looking at high quality ‘rural stations only’ gives almost the same (lower) trend as removing airports, but, once again, rural sites not at airports have a still lower trend.

However using min-max sensors (MMTS) that provide the best quality of data at only rural sites and excluding airports results in an easily dismissed rate of 0.32°C/century. Whoda thunk it?

And how was this achieved? Why by good old-fashioned measurement and checking against new classification data of course.  It seems eminently sensible that heat bias should be estimated, not just by distance to a heat sink or source, but also by the size of the source (the area of concrete or whatever) – a World Meteorological Organisation endorsed method for heaven’s sake.

Now that this cat is out of the bag (and among the pigeons) it is going to be hard to make it go away as it sets a new standard where others must play catch up; it also takes away a few favourite toys (adjustments).  Anyone who overlooks the significance of this paper just hasn’t thought it through.

Images from Powerpoint presentation; full paper and figures here.

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2 Responses to Location Location Location

  1. Bloke down the pub says:

    All it needs now is for the media to take notice and give it the attention it deserves.

    [Reply - indeed. V.]

  2. peter azlac says:

    Verite

    The addition of surface area of the heating zone is a welcome addition to the evaluation of UHI – though the real answer is to reject all station data where such effects exist. The new evaluation by Anthony Watts highlights the shortcomings of GHCN in this respect but still does not account for the fact that even the best rural stations can give false trends due to changes in soil water content with the swings in ENSO and other factors, or changes in the “roughness” of the surface due to changes in land use that affect night time turbulence and hence inversion that raises Tmin. These are covered in the following papers:

    Important New Paper on the Nocturnal Boundary Layer, Mixing, and Radiative Forcing as it applies to GHCN weather stations

    http://wattsupwiththat.com/2012/07/12/important-new-paper-on-the-nocturnal-boundary-layer-mixing-and-radiative-forcing-as-it-applies-to-ghcn-weather-stations/#more-67338

    New analysis finds water vapor is a negative feedback

    http://hockeyschtick.blogspot.com/2012/04/new-analysis-finds-water-vapor-is.html

    http://clivebest.com/blog/?p=3597

    http://clivebest.com/blog/?p=3597

    [Reply - interesting site that last one. Thanks. As it is late here (again) I need to get to bed rather than reply to comments, but there is much more more to say on this issue. V.]

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