Part 1 Enso Temperature Correlations

[Iceberg]

Attached is a quick document I've put together to help show that the recently observed global cooling is fully consistant with the AGW thoery, of a continued background warming and of short-medium term global temperature variations.

"The purpose of this study is to examine the recent cooling observed in the temperature record 07-08, compare this to past temperature constructions and primarily to the ENSO signal to identify a causal effect between the two.

To achieve this objective the MSU (TLT) dataset was used, partially as this is he most sensitive temperature dataset to atmospheric processes, but also because it’s the dataset used by those more skeptical of Global Warming as it cannot lay claim to any UHI (Urban Heat Island) effects.

The ENSO signal dataset used is provided by NCEP/CPC."

"Conclusions.

There is a strong correlation between ENSO and Global temperature variations over the short to medium term.

Longer term shows a neutral ENSO should cancel out these short-medium term variations. So ENSO is not a climatic driver but a variation factor.

The MSU temperature record shows a steady background temperature increase, this is evidenced by the relatively high minimum temperature reached during the 07-08 La Nina event.

The cooling of 2007-2008 is fully consistent with natural temperature fluctuations, there is NO evidence to suggest that is it part of a new background cooling phase. Indeed the comment above indicates that the warming phase is still very evident."

[VillagePlank]

Nice to see a PDF!

First criticism - drop the linear trend lines. Linear trend lines shouldn't really be used to model natural phenomena. Avoid polynomial ones, too - best, I reckon, to stick with moving averages.

Nice to see ENSO and temps put together though - quite amazing, in my opinion.

Edited October 27, 2008 by VillagePlank

[Shiny_Bottom_1]

Thanks Iceberg.

Interesting reading.

Can I ask though. What would happen if you made the two x axis the same variation, rather than using different plot scales up each side?

Edited October 27, 2008 by Shiny_Bottom_1

[Iceberg]

I agree re the trend lines, it's far from ideal and shouldn't be used as an exact trend but is rather to show a general point. STats is not my strong point.

SB, I started it like that but the ENSO graph overwhelms the the smaller variations of the temperature, the correlation is still there between the peaks and troughs but now it can be more easily seen.

[acbrixton]

"STats is not my strong point."

Iceberg, you do yourself a considerable injustice!

Many thanks for taking the time to produce such a useful and illuminating paper.

regards

ACB

[Iceberg]

If stats isn't my strong point, spelling and grammer certainly isn't.

I will re-publish it tomorrow, with a number of spelling and grammer corrections, my apologies.

[Thundery wintry showers]

Moving averages are an excellent idea here as they'd show some of the short-term variability as well as the overall trend. It seems clear to me from the existing graph, though, that the global temperature anomalies consistently show more of a negative bias relative to ENSO early in the record than towards the end of the record, thus suggesting a background warming trend.

As for the graph scales, on one hand, having the same scale on both axes might be consistent, but on the other, it would make global temperature anomalies look practically non-existent. I'm guessing the two scales were chosen to make the anomalies broadly match.

[Android]

nice analysis. The conclusion is pretty much along the lines of what I think regarding the '07/'08 cooling, although I also think it explains at least some of the post 2002 flat period too (you can even see ENSO declining slightly since 2002)

Here's a similar image (although I didn't graph* ENSO I just noted the ninos and ninas) I made a while back. I also included tacked on a copy (in green) of coming out of the 89 nina as a kind of prediction. The red trend line is just an eyeball guess.

The ~3 month lag you mention between ENSO and UAH can also be seen between global sea surface temperature and UAH too:

http://www.woodfortrees.org/plot/hadsst2gl...:1990/normalise

Probably because ENSO impacts global SST so significantly. What's interesting is this seems to give a preview of upcoming UAH months.

Side notes:

-Mt St Helens is marked to explain the 82 cooling but I think El Chichon 82 eruption is the normal explaination.

-Not so relevant, but I suspect that ENSO is by definition zero trend over the long term because it is derived by detrending sea surface temperature variations in the ENSO pacific regions (I don't know this for sure though).

*actually I should add I didn't graph anything, the actual graph of temp is from somewhere else I can't recall, perhaps one of those blogs tracking temps from month to month. I just overlaid a badly scrawled mess over the top.

Edited October 27, 2008 by Android

[Iceberg]

Out of interest and taken from the next document I am trying to get done, this is a 30 rolling year average based upon the longest global temperature series I can find the HADCRU based upon the recorded anomaly.

Again it's very clear where the climatic warming trends are. (Notice we are using 30 year averages so we can claim to be monitoring climatic changes.

It's also very noticable the ture effect of the recent cooling (this graph goes upto Sept 2008).

Also noticable are the yearly ups and downs where cooling is more evident in certain seasons than others.

[Iceberg]

A bit of an update on this from the Met Office with there thoughts for 2009 and the effects in 2008.

Needless to say this is exactly by thoughts as well and shows a very valid thought to all this, what we need is a moderate El Nino event to occur over a reasonable time frame to allow us to go back to the warmth, personally I think this will happen sooner rather than later.

http://www.metoffice.gov.uk/corporate/pres...pr20081230.html

2009 is expected to be one of the top-five warmest years on record, despite continued cooling of huge areas of the tropical Pacific Ocean, a phenomenon known as La Niña.

According to climate scientists at the Met Office and the University of East Anglia the global temperature is forecast to be more than 0.4 °C above the long-term average. This would make 2009 warmer than the year just gone and the warmest since 2005.

During La Niña, cold waters rise to the surface to cool the ocean and land surface temperatures. The 2009 forecast includes an updated decadal forecast using a Met Office climate model. This indicates a rapid return of global temperature to the long-term warming trend, with an increasing probability of record temperatures after 2009.

Professor Chris Folland from the Met Office Hadley Centre said: "Phenomena such as El Niño and La Niña have a significant influence on global surface temperature. Warmer conditions in 2009 are expected because the strong cooling influence of the recent powerful La Niña has given way to a weaker La Niña. Further warming to record levels is likely once a moderate El Niño develops."

[Methuselah]

Nice post, Iceberg. Thank you. And not much room for the skeptics' sleight-of-hand treatment there either, you wouldn't think?

[Iceberg]

Right I've not been a frequent poster on here mainly because I working on looking at the various natural processes to see if it's plausible that they might be accounting for the current global temperature trend.

I've looked at ENSO and it seems to show a tight short/medium term correlation with an underlying warming trend.

The two main areas that are often quoted are PDO and Solar. I am working on Solar still which is a larger piece of work. But as a said step and since it's closely related with ENSO this is how the PDO stacks up.

The data is really simple and consists of a monthly plot of Hadley data taken monthly(globally) against PDO values as given by the Washington Education centre.

http://jisao.washington.edu/pdo/PDO.latest

The plot is then given a 10 yr moving average to filter out noise and to allow for trends. 1930 was taken as the start time as this is when the PDO figures start and for no other reason.

Again I am not aware of anybody doing this but they might well have.

The Data is pretty conclusive IMO.

There is a large link between ENSO and PDO, this is well documented.

There also seems to be a link between PDO and Solar.

The PDO Temp 10 year correlation is very evident until approx 1990, from then on PDO trends down and temps trend up. To me this is a clear indication of another forcing mechanism effecting global temps, largely from 1990 onwards. W know from the ENSO work above that this isn't ENSO.

So it could be Solar or it could be GHG. Solar has been trending down since 2000 though so this is very unlikely to be the reason IMO.

Edited March 9, 2009 by Iceberg

[Iceberg]

Forgot to say white is temperature, green is PDO.

[johnholmes]

another interesting post from you Ice

It would seem at a quick glance that both are on the way down or about to start on their way down, or are my olde eyes mis reading that?

[Iceberg]

Thanks John, yes the 10 yr average trend has just started to nose down a touch, IMO the safe bet is that this is in response to La Nina conditions since Jan 2007 which could in turn be down/effected by the more negative PDO, there could equally be a Solar influence in there as we've pasted the solar minimum during 2008. Natural processes have certainly combined to call a halt to the warming in recent years.

[Iceberg]

A few thoughts from me.

I might be being really simplistic here, but....

The output from the sun has been very low recently as people are fond of saying solar minima and all that.

Now if this is going to have an effect on the earth then surely the effect would be felt first in the higher reaches of the troposphere and the middle troposhere. ?.

I can understand a lag further down near the surface as you have interaction with ocean and atmospheric and ocean coupling etc. There will be an element of this higher up in the troposphere but any lag should be having much less effect.

However a quick perusal of the tropospheric temperature data from MSU indicates that temps in the middle and upper troposphere are still above average (compared to the 79-00 average) and could still be called high.

It will be interesting to see if there is going to be any change here from the solar conditions over the next few months but the data atm doesn't support it.

Going on from that a few observations that I also found interesting but I should add I doubt this is anything new to those that have looked at it before.

Attached are the global temperature profiles which are very neat in themselves.

The TLT one:

Shows very nicely the warm up of the arctic and the northern mid latitudes over the past 10 years. Also the comparible stability of the Antarctic.

Also on here are the equitorial effects of the 98 El Nino and the following La Nina and the recent La Nina.

What's also interesting are the arches that branch out north and south of the tropics following a El Nino (the late 80's and late 90's in particular). Note, this could be one of the reasons why we tend to have crap winters following an El Nino for the year or 2 after an El Nino has disapated.

It's also no wonder that the Arctic ice has struggled recently. The Camels back must be really aching.

The TMT:

Moving on the middle troposhere what's surprising is that the although the temperature record maps almost perfectly with the lower troposphere elsewhere it doesn't for the Antarctic where there is a marked difference between much cooler TMT anomalies and average TLT anomalies.

Moving on to the stratospheric anomalies.

It's obvious this has got cooler and cooler over the past 30 years.

I will keep my comments here brief as they are probably contentious when I say that if GHG's are stopping more heat and reflecting it back to the surface, then you would expect the stratopshere to cool and the troposphere to warm, funny how that works out isn't it.

[jethro]

Doesn't Ozone have a role to play in all this? Can't remember all the details, High Pressure is a mine of info though; I'm sure he's posted stuff related to troposphere/stratosphere temps.

[BrickFielder]

la nina will have played a part in recent cooling, however I think you should look towards sunspot activity for the lack of warming since 2002.I know the link between cosmic rays and clouds has been debunked but there does appear to be some linkage.

What is particularly noticeable is the reduction in high level cloud over recent years, and I cannot help but link this either to ozone or lack of a serious volcanic eruption.

What does concern me is the step changes in stratospheric temperatures as this does not coincide with a picture of gradual warming. That is not to say warming is not going on just that there appear to be step changes which trigger a change of state. Those triggers being volcanic activity and perhaps ozone layer changes. This could imply any recent recovery in the ozone layer could create further climate change at the next volcanic eruption (current thinking is that ozone increase, warms the planet)

You perhaps can see those steps even in surface temperatures, although this is not a particularly good graph and I think the argument is taking some liberties.

One key indicator for a warming planet ought to be a reduction in outgoing radiation which really is not apparent, the implication being that short wave absorption has changed. Still it is not what I would have expected in terms of the planetary radiation budget.

Geting back on topic we should also not forget that there was some sort of climate shift for the Pacific in 1976, or perhaps more likely there is some sort of decadal oscillation involving the humbolt current.

Ocean climate shifts

Non of this implies global warming is not going on just that there are a lot of factors and natural oscillations which need to be taken into account.

[Iceberg]

A very good and detailed post BF.

A couple of quick observations would be.

- Is the reduction in high level cloud attributable to the reduced effects of Global Dimming, (less high atmospheric pollutants causing a reduction in cloud creation).

- My understanding of GHG's is that they will warm the lower layers of the atmosphere but cool the higher layers. Due to less outgoing radiation ?. Saying that the Role of Ozone depleation is very likely to play a part in Stratospheric cooling I think this was raised as an area that needed much further study in AR4.

Again My belief is that it will effect the transfer of heat from Equator to Pole but not the total heat budget for the earth and therefore global temps. But this is a best guess.