Temperature Adjustments In Alabama
By Paul Homewood
I briefly mentioned the new nClimDiv Dataset, introduced by NOAA this month. Let’s take a closer look at how it affects Alabama.
A comparison of the annual mean temperature for 1934 & 2012, under the new NCDC system shows:
1934 | 2012 | Diff |
63.4F | 64.9F | 1.5F |
So they claim that 2012 was 1.5F warmer, but is this supported by the individual temperature records?
There are only 13 stations that have records for both 1934 and 2012, and they are listed in the Appendix. They are distributed across eight Climate Divisions.
Using the State Climatological reports for 1934 and 2012, we can compare annual mean temperatures for the two years. These are then averaged within each division, and these divisional averages are weighted by area to give a Statewide figure.
To summarise the results:
1934 | 2012 | Diff | |
NCDC | 63.4 | 64.9 | 1.5 |
Station averages | 64.9 | 65.1 | 0.2 |
Difference | 1.3 |
Somehow, the new NCDC system finds an extra 1.3F of warming, that does not exist on the individual station analysis.
It is worth pointing out that only one site, Gadsden, records a difference of 1.5F or more. According to Wiki, Gadsden has a population of 37000, and the station metadata shows the weather station slap bang in the middle of a water works. It may be that Gadsden is therefore not a reliable site, and it certainly is an outlier.
It is true that temperatures since the 1930’s have been adjusted for TOBS (Time of Observation Bias), but according to NOAA, this should only account for about 0.3F, which still leaves a gap of 1.0F to explain.
The usual excuse thrown for these differences is the all encompassing “homogenisation”. But the above stations are all discrete records, and have no need to be homogenised. And as can be seen from the Appendix, which shows populations, many of the sites have quite sizeable populations, so some allowance should be made for UHI.
It is clear that the new NCDC system is not reflecting the reality on the ground, and is artificially adding a significant amount to the warming trend since the 1930’s.
APPENDIX A
Alabama Annual Mean Temperatures
DIV | POP | 1934 | 2012 | DIFF | |
X 1000 | |||||
1 | DECATUR | 84 | 63.8 | 63.4 | -0.4 |
2 | SCOTTSBORO | 14 | 61.7 | 62.3 | 0.6 |
ST BERNARD | R | 60.8 | 61.7 | 0.9 | |
DIV 2 | |
61.3 | 62.0 | 0.8 | |
3 | CENTREVILLE | R | 64.4 | 63 | -1.4 |
CLANTON | R | 64.4 | 63.9 | -0.5 | |
DIV 3 | |
64.4 | 63.5 | -1.0 | |
4 | GADSDEN | 37 | 62.6 | 65.6 | 3.0 |
5 | AUBURN | 57 | 65.5 | 64.8 | -0.7 |
6 | SELMA | 24 | 66.4 | 66.4 | 0.0 |
UNION SPRINGS | R | 66 | 64.3 | -1.7 | |
DIV 6 | |
66.2 | 65.4 | -0.9 | |
7 | BREWTON | R | 66.6 | 68 | 1.4 |
GREENVILLE | R | 66.7 | 64.4 | -2.3 | |
THOMASVILLE | R | 64.5 | 66.8 | 2.3 | |
DIV 7 | |
65.9 | 66.4 | 0.5 | |
|
|||||
8 | MOBILE | 443 | 67.7 | 69 | 1.3 |
R = <10,000 |
APPENDIX B
Temperatures Weighted By Division
WEIGHTED TEMPERATURE | ||||
DIV | 1934 | 2012 | 1934 | 2012 |
1 | 63.8 | 63.4 | 5.7 | 5.7 |
2 | 61.3 | 62 | 6.0 | 6.0 |
3 | 64.4 | 63.5 | 9.5 | 9.4 |
4 | 62.6 | 65.6 | 4.9 | 5.1 |
5 | 65.5 | 64.8 | 6.4 | 6.3 |
6 | 66.2 | 65.4 | 9.9 | 9.8 |
7 | 65.9 | 66.4 | 18.8 | 18.9 |
8 | 67.7 | 69 | 3.8 | 3.9 |
STATE | 64.9 | 65.1 |
APPENDIX C
Divisional Areas
AREA SQ MILES | WEIGHTED | |
1 | 4609 | 0.0893043984 |
2 | 5027 | 0.097403604 |
3 | 7648 | 0.1481883356 |
4 | 4000 | 0.0775043596 |
5 | 5006 | 0.0969967061 |
6 | 7716 | 0.1495059097 |
7 | 14719 | 0.2851966673 |
8 | 2885 | 0.0559000194 |
TOTAL AREA | 51610 |
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Anything to keep the global warming illusion alive. I wonder if original raw data is or will continue to be available.
Great post, re-posted at DTT dot com.
Thanks, Paul. Good article.
This is my view, inspired by your findings:
NCDC have introduced a new method for calculating state (but not national), temperatures in the USA. The new method makes the past cooler, creating a false impression of present warming at the state level. The national figures remain unaffected. This is because they were already being calculated under the new system, creating a similar false impression.
I have put it up in my climate and meteorology pages, with a link to your work.
An average equal to the solitary highest value? Nice work, if you can get it.