UAH v5.5 Global Temperature Update for November 2012: +0.28 deg. C
By Dr. Roy Spencer
After my extended trip to the West Coast, I am finally posting the global temperature update (sorry for the delay).
Our Version 5.5 global average lower tropospheric temperature (LT) anomaly for November, 2012 is +0.28 deg. C (click for large version):
The hemispheric and tropical LT anomalies from the 30-year (1981-2010) average for 2012 are:
YR MON GLOBAL NH SH TROPICS
2012 1 -0.134 -0.065 -0.203 -0.256
2012 2 -0.135 +0.018 -0.289 -0.320
2012 3 +0.051 +0.119 -0.017 -0.238
2012 4 +0.232 +0.351 +0.114 -0.242
2012 5 +0.179 +0.337 +0.021 -0.098
2012 6 +0.235 +0.370 +0.101 -0.019
2012 7 +0.130 +0.256 +0.003 +0.142
2012 8 +0.208 +0.214 +0.202 +0.062
2012 9 +0.339 +0.350 +0.327 +0.153
2012 10 +0.333 +0.306 +0.361 +0.109
2012 11 +0.281 +0.301 +0.262 +0.172
Werner Brozek
Yes the first entry is -0.26. Since the first satellite was launched in 1978 how did they get an average? Answer, they didn’t, it was -0.26 degrees lower in Dec 1979 than 1978.
However I see from the readme file that they calculate a 30 year running mean which is a useless number.
Thanks for all the replies to my question,
What is the value of 0.0 in the graph?.
the only one who answered it was Werner Brozek who quoted 288k which equates to 14.85c,
Is this correct?
Many Thanks for readers Input.
So can anyone tell me what 0.0 represents as a temperature on this Graph?
Since the first satellite was launched in 1978 how did they get an average?
The above is from two different people. I will give it my best shot and if others wish to improve on my answer, be my guest!
Apparently there has been a recent change to the official average global temperature. But let us for the moment assume the average is 15.0 C. Let us assume that globally, December is coldest and July is warmest. So let us now assume the average December global temperature is 14.0 C and that the average July temperature is 16.0 C.
So in December, 1978, the satellites measured an average temperature of 13.72. The 14.0 is the “0” for December, so a reading of 13.72 would get recorded as -0.28 since it is 0.28 below the average of 14.0.
In July, 2012, the anomaly was 0.13. If the average temperature in July is 16.0, then an anomaly of 0.13 means the average temperature was 16.13 or 0.13 above the “0” for July.
So it is entirely possible for the July anomaly to be -0.50 and for the December anomaly to be +0.50, yet the globe would be a degree warmer in July since the average temperature in July would have been 15.5 but it would have been 14.5 in December.
Now it gets tricky when different data sets use different base lines. In one thirty year period, the average range may have been 14.0 to 16.0, but a different 30 year period could have had an average range of 14.5 to 16.5. So an anomaly of 0.7 for one data set is the same as 0.2 in another data set, yet both could be measuring exactly the same temperature.
D.I. says:
December 13, 2012 at 5:51 pm
So can anyone tell me what 0.0 represents as a temperature on this Graph?
A simple question to my teachers but no definitive answer.
I know I’m going to regret getting into this – but here goes anyway.
The zero line represents the mean temperature for each month between 1981 and 2010. So there will be a baseline temperature for January which is the mean temperature for every January between 1981and 2010. Similarly for February, March …etc.
The recent anomaly for November 2012 is 0.28 which means that November 2012 was 0.28 degrees warmer than than the mean 1981-2010 November temperature. The anomaly represents a departure from the baseline ‘normal’.
Different datasets use different baselines which does seem to bother some people. GISS, for example, use the 1951-80 period. This means GISS anomalies will be generally larger than UAH but it is relatively easy to convert from one baseline period to another and , in any case, it is the trend which is the important rather than the size of the anomaly. The trend will be unaffected by the choice of baseline period.
Werner Brozek says:
December 13, 2012 at 7:41 pm
So can anyone tell me what 0.0 represents as a temperature on this Graph?
Since the first satellite was launched in 1978 how did they get an average?
The above is from two different people. I will give it my best shot and if others wish to improve on my answer, be my guest!
Apparently there has been a recent change to the official average global temperature. But let us for the moment assume the average is 15.0 C. Let us assume that globally, December is coldest and July is warmest. So let us now assume the average December global temperature is 14.0 C and that the average July temperature is 16.0 C.”
______________________________________________________________________________
Except for 1 eensie teensie problem. The UAH measures the temperature at 8000 to 9000 meters above sea level which is about -50 to -70 degrees.
DI:
See John Flynn’s explanation, if you still don’t get it.
I guess there are two points to note:
1) Using Monthly averages allows monthly temps to be published without having seasonal/time-of-year variations mask the variations you’re trying to see
2) The actual base value for the 0.0 point is not important
– the 0.0 point is not ‘normal’
– it’s just a reference point
– UAH used to use a 20-year average, but changed it to a 30 year average a year or two ago
– but the actual offset used to calculate the 0.0 temp for each month is not very important
– the important point is the slope, or non-slope of the graph
– this tells us if temperatures are trending up or down or flat
So don’t get too hung up on the meaning of the 0.0 line on the graph, in fact just ignore it, and decide for yourself if the trend looks to be significant or not
Steve B says:
December 14, 2012 at 2:33 am
Except for 1 eensie teensie problem. The UAH measures the temperature at 8000 to 9000 meters above sea level which is about -50 to -70 degrees.
Although Aqua05 seems a bit different, it would be interesting to see how they arrived at their very first value out at the higher altitudes. I do not know, but perhaps they took readings for a number of years before determining where the 0 point was up to that point in time.
Thanks for the replies Teachers,
So to come up with a baseline, someone, somewhere, must have decided where to start and after averaging all the monthly temperatures decided on a starting value of ?= 0.0.
What was it?and does it move?
If the answer to the latter is yes then I think we should refer to ‘Climatology’ as ‘Climastrology’
no other ‘Science’ would get away with it.
D.I. says:
December 14, 2012 at 2:34 pm
Thanks for the replies Teachers,
So to come up with a baseline, someone, somewhere, must have decided where to start and after averaging all the monthly temperatures decided on a starting value of ?= 0.0.
What was it?and does it move?
If the answer to the latter is yes then I think we should refer to ‘Climatology’ as ‘Climastrology’
no other ‘Science’ would get away with it.
Scientists on both sides of the AGW debate are perfectly happy to use anomalies relative to a given baseline period since it offers the most appropriate way of analysing changes in temperature over a period of time. The fact that you have problems with it suggests you lack the mathematical skills to understand how to interpret the data being presented.
As for your comment that “no other ‘Science’ would get away with it” I can assure you that many other sciences use similar methods to present data.
Remember this – Fahrenheit and Centigrade are effectively arbitrary scales which are used to represent temperatures experienced on earth. The Kelvin scale is the one that should be used as it represents all possible temperature extremes. On this scale the average temperature of the earth would be around 287K. Clearly, recent (last 30 years) warming would be barely distinguishable on any graph using this scale. This might appear attractive to those who wish to argue against catastrophic AGW (of which I am one). However, it should be recognised that a small relative decrease ( ~2%) on this scale represents a cooling of almost 6K which, on a global scale, would be enough to result in mile high ice sheets crashing tinto New York.
Thank-you Mr. Finn for your trouble to reply, (appreciated),however I think you missunderstood what I was asking.I do understand that the baseline can move up or down depending on the period in question but as I read “Our Version 5.5 global average lower tropospheric temperature (LT) anomaly for November, 2012 is +0.28 deg. C”.
+0.28 deg. C against what!, in other words what is the Global ‘average’ lower tropospheric temperature over the baseline period which is 0.0 in the Graph
What temperature value is 0.0 ?.
BY the way,Your quote,
“The Kelvin scale is the one that should be used as it represents all possible temperature extremes. On this scale the average temperature of the earth would be around 287K. Clearly, recent (last 30 years) warming would be barely distinguishable on any graph using this scale. This might appear attractive to those who wish to argue against catastrophic AGW (of which I am one). However, it should be recognised that a small relative decrease ( ~2%) on this scale represents a cooling of almost 6K which, on a global scale, would be enough to result in mile high ice sheets crashing tinto New York”
Well yes I do have trouble with the Maths,can you tell me what is 2% of the Kelvin scale is?.
P.S.
Only Joking, I do know what you mean,but no one ever gave me a definitive answer to 0.0=?,some say 288K you say 287K which is a big difference when people are fighting over tenths of a degree.As a ‘layman’ asking a simple question and getting a multitude of answers both supportive and derogative, I now bow out from this question.
Thanks to all who replied.
P.P.S 0.0=?
Only Joking, I do know what you mean,but no one ever gave me a definitive answer to 0.0=?,some say 288K you say 287K which is a big difference when people are fighting over tenths of a degree.
It’s neither 287K nor 288K – certainly not as far as the UAH measurements are concerned at least. The 0.0 baseline is the mean 1981-2010 temperature for a given month. The monthly anomaly is the departure from the mean 1981-2010 temperature for that particular month. November 2012 was 0.28 deg warmer than the mean November temperature for the 1981-2010 period as measured by orbiting satellites in the lower troposphere (LT).
O.K. Just looked back at this post,yes I know it is an anomoly graph for a certain period in time against the base line but the baseline SHOULD STATE THE TEMPERATURE REFERRED TO whether it be January or July.
Imagine in years to come when some-one looks at a graph like this and asks “Well what was the Temp in November in those days”
Some-one says “It is an anomoly graph of November 2012”
Another says “well what what was 0.0 temp for those years of November in those days”
Answer “Well nobody knows because it was not stated”
Do you see where I’m coming from on this ?