We’ve talked a lot about record cold and snow, now more from the “weather is not climate department”, and this time there’s a warm side to the story. I’d planned to write something about this, since several people left the UAH numbers in Tips and Notes, but Luboš Motl beat me to it, so I’ll give him the honor here. It will be interesting to see what some pundits do with this number, especially if they compare it to the longer 100+ year instrumental surface temperature record. – Anthony
From his post:
Global UAH: warmest January day on record
Source for this graph is here
Many people think that the globe must be terribly cold these days. We’ve seen huge cold snaps and snowfalls in Britain, Eastern parts of the U.S., Western Europe, Central Europe, China, Korea, and India where hundreds of people have frozen.
So these are almost all the important places, right? (At this moment, the speaker forgets that there are places such as Latin America, Australia or the Balkans which have been warm.) So the globe must be cool – cooler than average, people could think.
However, the daily UAH global mean temperature shows a different story. The early January 2010 was warm. And on January 13th, which is the latest day whose temperature is known, we have seen the warmest January day on their record. The brightness global temperature near the surface was
T = -16.36 °C
which may not look excessively warm 🙂 but it is actually 0.11 °C warmer than the warmest January temperature recorded by UAH so far – which was on January 5th, 2007 (-16.47 °C). Of course, some alarmists might feel happy for a while. They’ve been afraid that the worries about a new ice age could escalate. And they’ve been saved: the global weather is warm again. The strong El Nino episode could have helped them – or someone else. It’s important that they’re saved. 😉
However, there is another, more important consequence of these numbers. And it is the following: the global mean temperature is irrelevant for you and for everyone else, too. It didn’t help the hundreds of frozen people in India, the passengers whose flights were canceled, and millions of other people in the European, Asian, and American civilization centers.
If you actually draw the monthly data from 1979 to 2009 – the global ones and those in e.g. Prague – you will find out that the correlation coefficient is just 0.17 – well below the maximum possible value of 1.00. It won’t be much higher outside Prague, either. 🙂
The Pythagorean average monthly anomaly in Prague has been something like 1.95 °C. Imagine that you want to use the global temperature in order to improve the estimate of the temperature in Prague for a given month. If you add the global anomaly and the expected local average temperature in Prague for the month, you will reduce the typical fluctuation from 1.95 °C to 1.92 °C or so – almost no change. The swings in the global temperature won’t visibly help you to improve the predictions of the local temperature.
So while it may be fun to watch the global temperature – a meaningless game that many people began to play in recent years because of the AGW fad (and yes, your humble correspondent only plays these games because others do, not because it is scientifically important) – it is very important to realize that the changes of the global mean temperature are irrelevant for every single place on the globe. They only emerge when things are averaged over the globe – but no one is directly affected by such an average.
Even if you accumulate a whole century of changes, the relevance of the global temperature will be essentially non-existent. A 1.5 °C warming of the global mean temperature is still less than one standard deviation of the monthly average at a given place. And the “local” climate may also shift – the January 2100-2150 average may be warmer than the January 1950-2000 average in Prague by much more than those 1.5 °C. Different regional climates change differently and most of these changes have nothing to do with the changes of the global mean temperature!
By the way, it’s almost certain by now that January 2010 will also be the globally warmest January on the UAH record – the anomaly will likely surpass 0.70 °C. It may even see the highest (or at least 2nd highest) monthly UAH anomaly since December 1978. I will print more exact predictions in a week or so.
I seem to remember that Dr. Spencer has warmed us in the past to avoid UAH daily data due to corrections that were applied only on a monthly basis. I also remember him saying this would be changed sometime *soon* back in August. Has the time arrived? Can we now look at daily data?
Anthony,
Are these Land-based Temperture readings or Satellite? TIA……John..
REPLY: Read the title – Anthony
Dr. Spencer’s calibration explanation says
“The variable emissivity problem is the smallest for well-vegetated surfaces, and largest for snow-covered surfaces. While the microwave emissivity of the ocean surfaces around 50 GHz is more stable”
So my question for Dr. Spencer is whether the large extent of snow coverage in the northern hemisphere throwing off the calibration for the daily AMSU temperature? Something that will be sorted out in the monthly result…
So are the warmists predicting more earthquakes?
So iguanas dropping from trees and the lack of feeling in my fingers and toes was because of the heat? That’s a relief.
Sorry I don’t get it, a global mean temperature of -16.36 deg C ? Given that 70+% of the surface is ocean, how can the global mean be way sub zero ?
Excuse my ignorance, but if the graph is of a global temperature average, how come it follows a northern hemisphere pattern and is warmer in the northern hemisphere summer?
REPLY: I believe the answer has to do with the majority of landmass being in the NH, but I’ll ask Dr. Spencer – Anthony
What is important about the cold January in the northern hemisphere is that it will cool the planet going forward. The albedo effect of the large northern landmasses covered with highly reflective snow is gigantic. The earth is right now reflecting away a significantly larger fraction of sunlight than normal.
People like Stephen Chu talk about the cooling effects of white roofs. Well that picture of an all white England–replicated across Europe, Asia and North America–will if it holds out for month create a thousand times more cooling than a hundred years of white roofs.
I saw on one of the alarmist blogs where commentators were saying that when it is cold in one place it must by definition be warm elsewhere: “What part of ‘average temperature’ don’t you get?”
That is true for a given planetary temperature, but it is not true going forward, where planetary temperature can change. All it takes is for outgoing radiative energy to exceed incoming radiation, and albedo is a big part of that equation.
Yes, Spencer did say to use *only* the previous year for comparison on the Explorer site.
Just by looking at the past years it is easy to see that this spike will drop by the end of the month. I do not see any spike in temperature that has lasted more than two to three weeks. Most likely will end up only half of the .7 C anomaly by the end of January.
Land temperatures have not been warm in January. It is unlikely that GISS or Had-Crut will show the same spike.
Is the raw data for this satellite audited by anyone?
Update on my analysis. If you plot the number of days above 30C (dropping) vs the number of days below -20 (also dropping) vs the length of winter (increasing) plotted together on the X axis and plot the average mean temperature on the Y axis you get a line where the correlation coefficient is -0.84 and a P value of essentually zero.
This means the average of the mean temperature is highly negatively correlated to cooler summers, shorter warmer and winters. Thus increasing the average mean temperature.
The data from 1921 to 2006 shows three clear phases of changes. 1935 to 1955 a decrease in the number of hot summer days by half, from 1956-1985 stable summer temps, and 1986 to 2006 an increase in summer days above 30 but still well below the first phase.
During that time the length of summer has increased linearly where we now have 30 days longer summers than we did in the 1920s.
During that time, the number of days below -20C has been cut in half in a linear trend.
I’m willing to send the preliminary results and data to anyone who requests it.
Kudos to Luboš Motl, but he really needs to cut out the smiley faces! 😎
“If you actually draw the monthly data from 1979 to 2009 … you will find out that the correlation coefficient is just 0.17”
This is a very poor correlation. Basically, there are no correlation. The whole notion of warming could be thrown out… with the water too.
Speaking of UHA Roy Spencer did a recent article featured here. In that article Roy said this….
“While this sounds like a good way to measure surface temperature, it turns out that the microwave ‘emissivity’ of the surface (it’s ability to emit microwave energy) is so variable that it is difficult to accurately measure surface temperatures using such measurements. The variable emissivity problem is the smallest for well-vegetated surfaces, and largest for snow-covered surfaces. While the microwave emissivity of the ocean surfaces around 50 GHz is more stable, it just happens to have a temperature dependence which almost exactly cancels out any sensitivity to surface temperature
This appeared to me to be very important, and very vauge. Do snow surfaces give a false high, or low reading? Does this increase the margin of error. Would the recently very high % of N.H. snow cover significantly effect these readings? And finally, What does the last sentance mean in regard to the oceans, 70% of our home.
Someone with understanding please respond, and thanks in advance.
“the length of winter (increasing)” Sorry, that should be:
“the length of winter (decreasing)”
Yesterday’s annular eclipse must have cool down the earth a little since it was the longest eclipse for more than 1000 years.
http://eclipse.gsfc.nasa.gov/OH/OH2010.html#SE2010Jan15A
when it is cold in one place it must by definition be warm elsewhere:
If the warmists are trying to convey that as meaning land, they are once again resorting to half-truths. 2/3 of the world’s surface is ocean, not land.
So, there is a 1 in 3 chance of that happening.
Having a disproportionately large area of the N. Hemisphere snow-covered reflects back into space the incoming. The oceans would be the warmer part, and they would be the ones losing on the deal, giving up thier stored energy in the imbalance, for the flow off the continents is colder. Upon hitting the relatively warmer oceans, they readily take up the warmer moisture.
The clouds formed will continue to rise in unstable air masses until they precipitate the water out, and the heat escapes.
Oops, there goes the heat: Less received by the snowy landmass and more pumped out of the oceans.
Rod (13:34:58) :
Excuse my ignorance, but if the graph is of a global temperature average, how come it follows a northern hemisphere pattern and is warmer in the northern hemisphere summer?
REPLY: I believe the answer has to do with the majority of landmass being in the NH, but I’ll ask Dr. Spencer – Anthony
The sea temperatures don’t vary as much as the land temps do, and the curve there is really only the top of a chart that starts at absolute zero.
Keeping that in mind, the variation is less than 1½ % .
The UAH daily data is brightness temperature ie the calculated temperature of a black body emitting the same radiation as measured. The true temperature can only be calculated if the emissivity is known. As long as emissivity is constant a trend of brightness temperature will follow the true temperature with a constant displacement. When emissivity varies problems arise. If the emissivity is rising with constant true temperature the UAH data will show an increasing brightness temp and warming. This is possibly what is happening at the moment with all the snow and ice around.
Is there a colour key for each of the lines plotted on the graph?
And I am finding a global average which varies through the year between ca -18C and ca -14C rather difficult to get my head around.
Hmmm, One wonders if there has been any adjustments made to the sattellite data, because where I’m sitting in Texas it has been cold, I have a friend in Nebraska, it is cold there, I have a friend in Idaho, it has been cold there, I have a friend in Germany, it has been cold there. I’m not sure I believe any of the temperature sets anymore…
-16 degrees C?
What has that got to do with average surface temperatures? These readings must be +25,000 feet high.
Surely this does not correlate with the monthly UAH surface figures?
REPLY: Your are right, but there are no “monthly UAH surface figures”. Lower troposphere, air above the surface at 14,000+ feet. If Global warming is happening, that is a place to look for trends. Warming also happens in the atmosphere related to CO2, H2O, and other GHG’s at these levels. – Anthony
The numbers from the same site plotted:
http://img69.imageshack.us/img69/2104/amsutemptrends.png
Note that the 1km altitude measurements showing the most rapid increase were discontinued for some reason.
I’m sure it isn’t to hide the incline!
The reason for discontinuing this measurement would be of interest.