UAH Global Temperature Anomaly Jumps in September

Takes a while for a hot apple pie to cool down — especially a big one…

This result is to be expected. Last September La Nina had taken a good hold. This September La Nina has been dead for four months.

In the last few years, the impact of the ENSO-El Nino-La Nina phenomenon on global temperatures has become much more clear.
The strongest El Ninos can increase global temperatures by about 0.5C (maybe 0.7C). The effect is lagged on average by about 3 months.
A La Nina, as well, can decrease global temps by about 0.5C as we have seen with the UAH temp data over the past 18 months.
Starting in about 1976, the ENSO shifted to more and stronger El Ninos. This temporarily increased global temps by up to 0.5C (but probably less since most of the El Ninos were average in strength).
The most important thing to note from this is how it affects a basic least squares trend line calculation of the data. The UAH temp trendline and the chart itself is slightly positive but at least half of this increased trendline is just because there was more El Ninos affecting it in the 1980s and 1990s and early 2000s.
The UAH trendline is +0.13C per decade or +0.065C per decade taking away the El Nino influence on the calculated least squares slope. Global warming theory says the trend should be 0.2C per decade (if we are to reach the 3.0C increase in temps predicted.)
Now that we are into a neutral ENSO, temps are back to the level that would be expected with a very low global warming impact from CO2 level. UAH is up over the last few months because there was a La Nina in 2007 and early in 2008. Now that we are in neutral territory, temps bounce back a little bit. but they are still far, far away from the temps that the models predict they should be at.
We should be at about +0.85C in the UAH anomaly if the models are correct but we are only at +0.16C.
The latest satellite pics of the ENSO region show that La Nina is starting to build back now as the trade winds have picked up again. The warmers will have to revise their models pretty soon since we are not seeing the warming they have predicted.
Maybe we will have to go through one more really big El Nino event and if temps don’t increase to the levels the models would have predicted (a UAH anomaly of +1.3C for example) they will be forced to admit the models don’t add up (and they don’t.)

Oh good, now it rises, now that the summer’s over and we’ve had our killing freeze. It’ll probably head back on down during the depths of winter, just to make things interesting.

Bill Ilis – Actually the 0.2C / decade number is for the next few decades of this century. To look at what the models were projecting before that we can use the numbers from the TAR.
These are baselined in 1990. Taking scenario A2 as representative : temperatures from 1990-2010 were forecast to rise 0.35C, a linear trend of 0.175C/decade.
The actual trend since 1990 as measured by UAH was 0.171C / decade.
Several people have attempted to remove ENSO effects from the data to reveal the actual underlying trend, notably ‘Waiting for Global Cooling’ by Robert Fawcett published by Bulletin of the Australian Meteorological and Oceanographic Society and also Thompson 2008“.
regards,

To John Phillip. CO2 has been increasing at 1% per year since about 1850. Why would its impact only start in the decades ahead. The 0.2C per decade trend should have been evident since at least 1945 when CO2 started rising at the modern rate.
The ENSO corrected temperature analysis from RealClimate you linked to is a complete whitewash that unfortunately looked good enough that people bought it. But it is a whitewash.
I said above that a strong El Nino can increase global temperatures by 0.5C. The 1997-98 El Nino increased temps by as much as 0.7C.
What does RealClimate do to the 1997-98 El Nino – a correction of 0.15C. The analysis just tries to preserve the increased ENSO caused trend in temps that would have been caused by GHGs. Look at it again. There is nowhere near enough correction applied for the ENSO effect.
http://www.realclimate.org/images/enso_corr.jpg
In terms of the UAH trend since 1990 at 0.17C. Mount Pinatuba volcano erupted in June 1991 which dropped temps by 0.5C which again artificially increased that trendline if you start in 1990. If you start measuring the UAH trend in 1997 before the 1997-98 El Nino started, the trend is 0.0C per decade.

oops, a correction…that would be .055c cooling trend.

If you go ahead and make it a full 2 decades back to 1988, the trend is .158c/decade
Ah, nearer to the A1F1 scenario (rapid economic growth, emphasis on fossil fuels) then.
😉

Again, very similar to the mid 90’s during the last solar minimum. If solar cycle 24 is a low amplitude cycle, will be interesting to see how the Sat temps pan out over the coming years. I have a feeling this will probably be the highest spike for the next few months. Arctic ice seems to be rebounding even quicker than last year. Getting cold fast and it’s going to make for one heck of Winter season for the eastern 1/2 or 2/3 of the the U.S..

“Now I know this is just a snapshot,”
On the assumption of ‘eso no es un problema’, the upturn indicates dumped heat over the month. The models, whatever their limits, are turning south. Wouldn’t we expect, then, less intensity in a snap?

“if temps don’t increase to the levels the models would have predicted (a UAH anomaly of +1.3C for example) they will be forced to admit the models don’t add up (and they don’t.)”
Good analysis, unlikely outcome (honest candor).

if temps don’t increase to the levels the models would have predicted (a UAH anomaly of +1.3C for example) they will be forced to admit the models don’t add up (and they don’t.)
Given that UAH is baselined (zero-ed) on the mean temp for 1978-1998 and the model-projected trend is in the region 0.2C / decade, a +1.3C anomaly now would mean that ‘they’ would be forced to admit that the models had drastically underestimated the rate of warming.

Basil (11:14:08) :
Looking at HadSST2, NH SST’s were up a little in September, but not as much as UAH shows. Could this be explained simply by the difference between surface and troposphere conditions? E.g., did the troposphere over water warm up more than at the surface in September?
Just wondering.
Could the hurricanes explain it? i.e. by a transfer of heat from oceans to atmosphere. I’ve no idea if the manitude of the heat exchange is sufficient to account for the discrepancy over an entire month and on a global scale.

The September 2008 anomaly may have been +0.161 but it was still cooler them then September 2007 anomaly of +0.201 degrees.
That marks the 13 consecutive month of cooling temperatures.

I have a question…
Does the UAH do a data adjustment for UHI? I know this isn’t surface temperature measurements, so I’m just wondering.
REPLY: No UHI adjustment that I’m aware of. – Anthony

Mary Hinge: “(sigh) If you have been reading this blog over the last year or so then you should be familiar with the words ‘La Nina’”
And at the end of the La Nina it starts warming again! Looks like you just answered your own question.

Nope. 2008 will see colder temps than 2007. La Nina, La Nino, and any other nina/o that we haven’t discovered yet is small potatoes compared to the PDO which drives such events. Ever put your foot in the Pacific Ocean off of Oregon when it is in its cold phase? Think rapid freeze dried toes.

Nope. 2008 will see colder temps than 2007.
I never said 2008 would be warmer than 2007. I said global temperatures would be back to early 2007 levels within about 6 months, i.e. spring 2009 will be approximately as warm as spring 2007.
Often we make the mistake of thinking what we are experiencing locally is happening on a global scale. I accept you may be experiencing cooler than normal conditions, but over here in the UK I spent this afternoon sitting in the garden on what was a gloriously warm day. Large parts of Russia, the largest country (in area) in the world, has for the past week had temperatures
several degrees above above average over the last week.
As I write this I’ve been listening to the UK weather forecast and we’ve got more of the same. Temperatures well above average for the coming week.

George E. Smith (15:27:58) :
“It is actually the result of a sort of religious ritual; like the Catholic priest ata funeral walking around swinging a brass pot emitting smoke and waving it a round. His Congregation compar what he does with every other time they have seen him do it; or maybe they remember what they may have seen in a Russian Eastern Orthodox church. so long as the ritual doesn’t change, everyone is comfortable, even though they have no earthly idea what it means.”
“…purpose but to perpetuate the religious ritual.”
” just repeat the ritual the same way, and people will compare it to your last celebration.”
Why is it when trying to argue their very weak position with pseudoscience, people like this always try to paint the other argument as a religion.
This is a typical pseudointellectual response from a typical denier.