Problems With Temperature Data
SEARCH BLOG: CLIMATE and WEATHER
Last week I proposed a question to Dr. Roger Pielke, Sr., Anthony Watts, and Joseph D'Aleo:
I'm wondering if there is subset of the data used to track/calculate global average temperatures that is rural ['dark"] only? http://wattsupwiththat.com/The responses from Dr. Pielke and Joe D'Aleo were not as encouraging as I had hoped, but certainly illustrate the problems inherent in the present methodology for calculating a global average temperature:2009/07/15/giss-worlds- .airports-continue-to-run- warmer-than-row/#more-9184
It occurs to me that if there is such an unadjusted subset that can be filtered for stations that have a consistent location and cover the entire last century, it may provide a unique sampling basis for looking at global temperatures that have fewer environmental variables than the total subset. That might give a different perspective of the trend in world temperatures than the total population of reporting stations which are subject to all sorts of problems reported by Anthony. Certainly the data may be sparse in many continents, but it might be worth a look.
Are any of you aware of such an analysis?
- Such a binning (into rural/urban sites) is useful, however it is not as straightforward as one might suspect as there are a diversity of problems even with rural sites; e.g. see
Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229. http://www.climatesci.org/
For example, rural sites can be poorly sited (e.g. next to a building; adjacent to an irrigated field on one side, etc).publications/pdf/R-321.pdf
My bottom line conclusion is that the surface data has so many problems with respect to multi-decadal trends as a metric for global warming and cooling, it should be scraped all together. The upper ocean is the more appropriate metric; seePielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55. http://www.climatesci.org/
andpublications/pdf/R-334.pdf Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335 http://www.climatesci.org/
publications/pdf/R-247.pdf .The surface temperature data is still valuable with respect to weather patterns, and certainly agricultural interests can use the values for their needs. But as a climate metric, it has many problems. [Pielke] - Anthony mentioned to me many moons ago that none other than Gavin Schmidt argued that you could get a climate signal from just 60 well placed stations worldwide.
We talked about how we could find them and access the raw data before homogenization which is akin to mixing pure spring water with sludge. Claiming you improved the sludge but in the process made the spring water undrinkable.
Phil Jones claim, that he no longer has the original data but only the 'value-added' adjusted data is scary. I am sure there is raw data out there we can find but as Roger says, I don't know how easy it will be to get at the metadata needed to determine station history and whether it is one of the true desired rural locations.
One place to start may be the late and great John Daly's WHAT THE STATIONS SAY http://www.john-daly.com/stations/stations.htm He picked what he thought were representative worldwide stations with links to plots. [D'Aleo]
Perhaps you will find it disconcerting, as I do, that very respected individuals in the scientific fields of climate and weather have such serious concerns about the temperature history that is being used to establish our government's policy and spending priorities... and the influence on the rest of the world.
And if it's that difficult to come up with a clean sampling, how messed up must the total data set be?
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