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Guest post by Erl Happ

The Northern Hemisphere is having an old fashioned winter. I thought it might be of interest to look back at history for any lessons that might be there. I think that we already have enough data to work out what drives the climate system.

The Arctic Oscillation Index compares mid latitude sea level pressure with sea level pressure in the Arctic. There are other useful ways to compute the index based upon atmospheric phenomena that vary with the index but this is the simplest way to think of it.

The Arctic Oscillation Index and the Antarctic Oscillation Index change primarily with polar atmospheric pressure. The flux of pressure at the poles is large. In the mid latitudes the flux of pressure is small. If one observes these indexes (or polar pressure) over time it is plain that they frequently move together. Indeed, over the best part of the last sixty years there has been a loss of atmospheric mass and pressure at both poles. That process is now reversing, confounding a prediction that the AO would increase with the proportion of so called greenhouse gases in the atmosphere. The implications for the climate of the northern hemisphere are discussed in this post.

All data from http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl

Figure 1

Sea Level pressure at the poles in summer and winter

Let us imagine that a ( mysterious) force that is capable of shifting atmospheric mass away from the poles and towards the equator increases over a period of sixty years. Then it begins to relax. First to respond is the place that exhibits the largest inter-annual fluctuation, the Arctic in winter. It is like the canary in the coal mine. Since about 1990 there is a just a small gain in the Antarctic in southern summer. By contrast the Arctic, at precisely the same time of the year is, ‘up, up and away’.

Last to respond will likely be the Antarctic in winter, where pressure is higher than anywhere else on the globe. The Antarctic is a large block of ice about as big as the USA and it doubles its surface area in winter. The southern hemisphere at any latitude is colder than the northern hemisphere at the same latitude. The pressure that the atmospheric column exerts at the surface depends upon its temperature and density. There is a natural swing of atmospheric mass towards the winter hemisphere. Cold air is denser, warm air is less dense. So, depending upon the relative temperature of the hemsipheres the swing is modulated from season to season. It follows that Arctic pressure depends upon Antarctic pressure. The Antarctic is far and away the bigger sink.

So, Arctic sea level pressure has been increasing fast since 1990, both in summer and winter as we see in figures 1 and 2.

Figure 2

SLP is sea level pressure. 12 MMAV is 12 month moving average. AO is the Arctic Oscillation Index.

If we tip the AO on its head (as in figure 2) we see that the Arctic Oscillation Index is actually a very good measure of sea level pressure in the Arctic. Notice that the right hand axis of figure 2 is reversed with negative values on top.

Just in passing, do you notice anything in particular about figure 2? It’s like petals on a flower, or the decoration on the rim of a swirling skirt. Pressure is moving in accord with a natural process, yet to be discovered. There is no suggestion that a natural driver is being distorted by a new, third force that is giving polar pressure a downward tilt. Arctic pressure and the AO index are as high today as they have been at any time in the recent past.

Figure 3

The Monthly Arctic Oscillation Index

In figure 3 we have the AO again but this time, the conventional way up and presented not as a twelve month moving average of monthly data but as raw monthly data, a thirteen month moving average and a fitted second order polynomial trend line. The interesting patterns in the de-seasonalised data of figure 2 have disappeared. If the polynomial curve is to be trusted as a summary of trend, we might say that the AO index has gradually risen over time but, the rate of increase has become less and less. The index is now just a smidgen below the high point that it reached about 1998. And, just to emphasize the point that things are changing, it has recently fallen into a hole. That hole is the period from December 2009 to May 2010. The data does not reflect a similar plunge in December 2010 because it only goes as far as November.

What is going to happen if we are now entering a period where sea level pressure in the Arctic is no longer subject to the insistent pull of Antarctica.

Figure 4

The monthly AO and the anomaly in sea surface temperature at latitude 30-50 north

From 1948, sea level pressure was not only high in the Arctic but for thirty years it kept rising.

As figure 4 shows the AO just happens to correlate fairly closely with sea surface temperature in the mid latitudes.

Here is a closer look at that period. Sea surface temperature is now on the right axis that is scaled so that the relationship is easier to assess.

Figure 5

AO and anomaly in SST 30-50°N

It looks like sea surface temperature declined at a faster rate than the AO.

In figure 6 dWN refers to the differential pressure driving the Westerly winds in the Northern hemisphere. That is gauged by subtracting the sea level pressure at latitude 50-60° north (the sink) from the sea level pressure at latitude 30-40° north (the source). The letters dEN refer to the differential pressure driving the Polar Easterlies southwards in the Northern hemisphere. That is calculated by subtracting the atmospheric pressure at 50-60° north (the sink) from the atmospheric pressure at 80-90° north (the source).

Figure 6

The differential pressure driving the Polar Easterlies and the South Westerlies in the northern hemsiphere

Figure 6 is not easy to read. The polar easterlies (dEN is colored blue for cold) actually fluctuate much more than the south westerlies (dWN is colored orange for warmth). The right hand axis where dEN is plotted has a spread of 30mb and the left only 12 mb.

If the differential is negative that wind can not exist. It doesn’t even get out of bed. Its probably easier to conceptualize reality if you cover up the all that portion below zero on the vertical axis.

The warm south westerlies did not get out of bed for many short intervals up to 1969 but the cold polar easterlies were active and influential. This is what you can expect when the AO is low. After a period of low flux between 1969 and 1980 the relationship flipped. The Westerlies came into their own and the Easterlies experienced repeated intervals of slumber. The Easterlies sunk to abysmal depths of invisibility when Arctic pressure fell into a deep hole in the early 1990’s as Antarctic pressure bottomed. But Antarctic pressure is now increasing and the Easterlies are making their presence felt.

And that has a lot to do with why the ice in the Arctic comes and goes, the polar bears have been swimming further between meals and you are now shoveling snow as the price of orange juice is rising.

If you want to reproduce my sea surface temperature data please use the same database, calculate the average for the entire period and work out the anomaly from that.

Postscript: I have been wondering why Southern Greenland and Hudsons Bay have experienced unseasonable warmth at the same time as entire continents froze in December. Here is my best shot:

There are four factors contributing

1. Warm air descends from the stratosphere. As soon as the AO goes negative we see a geopotential height anomaly appear at latitudes higher than 60°north representing ozone rich air that absorbs long wave radiation from the Earth. There is no UV to be had in the polar night. So the source air in the descending polar circulation is warmer. It represents air slipping down through the ozone profile with more above and less below.

2 The warmed source air is further warmed as it descends via compression. In the polar regions, during the polar night, the air at the surface is warmer that the surface itself.

3 As Tom Rude points out in the last Arctic Ice thread: ” at the front of the high pressure anticyclones that brought cold and froze lemon trees in Florida the strong temperature gradient will force the advection of a huge amount of warm and moist air northward, that very same air that dumped snowmaggedon on the NE USA recently.”

4. All forms of precipitation release latent heat.

But all this is temporary because continued low AO will suck the guts out of the westerlies and promote the polar easterlies as it did between 1940 and 1978 and the Arctic will freeze over again. So, what you are getting at the moment is a taste of an old fashioned ice and snow promoting winter. The warm moist air will still come up from the tropics but it will be fighting cold Arctic air all the way. It’s a winter circulation pattern in the northern hemisphere rather than the all year circulation pattern that exists in the southern hemisphere.

The Arctic and Antarctic circulations are different beasts to a regular subtropical high pressure cell of descending air where the highest pressure is in the centre. The centre or vortex of descending air represents a low pressure zone. As the atmospheric shift occurs increasing the general level of polar pressure circulation intensifies the whole caboodle descends to the surface (its usual habitat in the Arctic is in the stratosphere) and starts to do what happens in the Antarctic all year round. This is really a case of the dynamics that drive the stratospheric circulation becoming apparent at the surface. What happens in the stratosphere is determined in the stratosphere, it is a function of the stratospheric circulation and the night jet that starts in the mesosphere and the dynamics alter with the shift of atmospheric mass to the Arctic. Those who would suggest that it is all driven from the troposphere are deluding themselves. It is their want to consider the atmosphere as a closed system so that their AGW fantasies are cosseted and conserved. I would hope that there is a bit of soul searching going on at the moment amongst those who can see the big picture.

My explanation of climate dynamics focuses on shifts in atmospheric mass over time and I see this as a function of external stimuli.

I am aware that sea surface temperature is modulated by the activity of the adjacent pole as it determines the flux of ozone into the troposphere. But that is a story for another day.

I can not imagine any internal dynamic that would produce a swing in Antarctic sea level pressure over 100 years. But I am aware of an external influence that does vary on 100 year time scales.

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RACookPE1978

Interesting. Have not seen atmospheric pressures at sea level analyzed chronologically/hemispherically before.

Hmmmm…
I shall watch the Cryosphere Today website with interest in the coming weeks, to see if the Arctic freezes over as you predict.
OT, but does anyone know what has happened to Spencer’s Latest Global Temps at http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps+002? For the last couple of days it has no message. I hope it hasn’t been nobbled.

Julian Braggins

Great work. Interesting how studies of fish production led to great strides in the knowledge of ocean currents and temperatures, and now a great interest in grape production may give insights into global air currents and temperatures.
Follow your dream?

Nigel Brereton

So the probability is that Northern hemisphere winters will be cold and harsh for the next couple of decades? Kind of falls into line with other non AGW forecasts with a believeable explanation. Thanks Erl

Paul Vaughan

Erl Happ wrote, “I am aware that sea surface temperature is modulated by the activity of the adjacent pole as it determines the flux of ozone into the troposphere.”
Erl, I challenge you to summarize the mirror image pattern in a single color-contour plot. If you succeed, this should attract considerable interest.

Geoff Sherrington

Stupid, fundamental question follows. Why does the atmospheric pressure not settle at an equilibrium, or at least a more steady pattern that follows insolation? There is a lot of energy required to change those baro pressures. From where does it originate?

This is a totally new line of thought to me. The proxy records show long term oscillations that are difficult to account for with the sea currents that are currently explained. Such a long term elastic band effect of mass moving with the polar winters could really be significant. Very interesting idea’s here.
John Kehr
The Inconvenient Skeptic

Paul Deacon

Erl – old timers in Queenstown, New Zealand, have suggested to me that the winter weather pattern for the last 2 years is reverting to the pattern of 30+ years ago (longer and deeper periods of cold). So it may be that the Southern Hemisphere is having an old fashioned winter too.
All the best.

stephen richards

Erl
If you didn’t know about the 3 periods of warm-cold-warm from ’48 to now, would you be inclined to form 2 trends from ’48 to ’90 and ’90 to now in figure 2 ?

The overwhelming theme in Erl’s presentation is the exterior influences on world climate. Sitting here tonight in Australia I am dumbfounded by the level of destruction happening in our north which is also affecting the whole eastern coast. I have been expecting a severe northern winter along with very high rainfall for Australia but the levels are even higher than I imagined. Is this what we are to expect in the coming years and are we ready for it?
The last time we had a similar external influence was around 1815, where the world was in a very different place, population densities and food resources are now more finely tuned. If we can look forward and compare how the future might compare with the Dalton, I am of the opinion looking at the data that we will be hit hard, and this will be short lived. Australia is going to be severely impacted economically along with the high humanitarian cost incurred by the current floods, similar destructive forces are in place in the northern hemisphere. It is also early days as the Sun refuses to kick start….I am starting to feel very uneasy.

Alexander Vissers

The most convincing part is the recognition that we do not know what drives any of this, the “mysterious force”.

stephen richards

Let us imagine that a ( mysterious) force that is capable of shifting atmospheric mass away from the poles and towards the equator increases over a period of sixty years
Now here’s a thought. The angular velocity of the planet would (one might conjecture) change the mass/pressure at the poles. As its’ velocity increased the atmosphere should compress at the poles and as its’ velocity decreased the atmosphere should decompress. Angular momentum is influenced by the solar wind which is currently at historically measured lows. This should mean a decrease in pressure at both poles will follow as would an increase of pressure at the equator. The difference between the 2 could be significant (statistically)

Stephen Wilde

A very good and insightful report and so far as it goes I agree with Erl’s general interpretation of the overall climate system.
We just need to firm up the mechanisms whereby those variations are imposed on the AO and AAO.
Erl is heavily into the mechanics of ozone reactions and I agree that that is likely to be where the answer lies.
Add to that the top down effects on cloudiness and albedo when the jets become more meridional or more zonal thereby altering energy input to the oceans and one can then see a very effective top down amplification system.
I have some slightly different suggestions from his which I have expressed elsewhere and it will be interesting to see where new data leads us all.

Robert Ellison

G’day Bruce,
Can I be a hemispherist? Can’t be bothered with the Northern Hemisphere at all – the main climate game is in the south.
The AAO – more properly known as the Southern Annular Mode (SAM) – is of course defined as the index of SLP anomalies between high and mid latitudes. The SAM had a positive peak in the late 1990’s. A positive index is defined by convention as lower relative SLP at higher latitudes.
The pressure differential influences the path of storms spinning off the polar vortex. A positive SAM sees storm tracks staying further to the south – something that is reflected especially in winter rainfall over Southern Australia – but also has an influence in fewer southerly fronts that sweep across the country as a welcome summer relief.
In a negative SAM – storms push cold surface water into higher latitudes – which then accumulates in the area of the Humboldt Current. This I believe is the trigger for a La Nina. Cold sub-surface currents push more easily through the cooler surface layer. This sets in train a series of changes involving wind, cloud and currents that evolves into the La Nina pattern of cold surface water in the central Pacific – and hence the role of SAM in the major mode of global climate variability. Am I wrong in thinking that this was your theory?
Did you hint – or more than hint – that the changes in the polar oscillations are driven by changes in solar UV? See the following relevant sources. Lockwood et al discuss ‘top down’ forcing by solar UV. Judith Lean links it to ENSO variability – although without defining a mechanism.
Lockwood, M., Harrison, R., Woollings, T. Solanki, S., (2010) Are cold winters in Europe associated with low solar activity? Environ. Res. Lett. 5 (2010) 024001 (7pp)
Lean, J., (2008) How Variable Is the Sun, and What Are the Links Between This Variability and Climate?, Search and Discovery Article #110055
A final important point is that tropical and sub-tropical cloud cover is negatively correlated with seas surface temperature – which of course changes most dramatically in the central and northern Pacific. ‘Tropical and subtropical low-level marine clouds consist of optically thick stratocumulus clouds, which usually form over the regions associated with relatively cold sea surface temperatures (SST) and atmospheric subsidence, and optically thin shallow cumuli in the tradewind regime. These low-level clouds play a pivotal role in the global climate system not only by affecting radiative budgets but also by promoting heat and moisture exchange between the sea-surface, the boundary layer, and the overlying troposphere.’ Zhu, P., Hack, J., Keilh, J and Zhu, P, Bretherton, C. 2007, Climate sensitivity of tropical and subtropical marine low cloud amount to ENSO and global warming due to doubled CO2 – JGR, VOL. 112, 2007
Given the centrality of ENSO (or Pacific SST more generally) to decadal climate change and looking at ISCCP, ERBE and CERES data – this is the key to most of recent global warming. If UV is driving ENSO – I’d hazard that we are looking at long term global cooling.
Cheers
Bruce

kzb

Off the immediate topic, but anyone in the UK watch TV last night?
First thing, “Horizon” -comedian physicist Ben Miller with a shameless thinly disguised propaganda piece, on the surface it was about temperature measurement, but really about global warming of course.
Second, what about the undercover cop in the climate action group? This is being sold on the BBC as an undercover cop “going native” in an environmental action group. However, it is clear that this person was actually the “ring leader”, acting to plan, motivate and facilitate so-called direct action, such as invading a power station site ! How many other climate protests are actually instigated by state agents we ask ?!

Another Gareth

Changing the distribution to put more molecules where the solar radiation is strongest would increase the amount of energy absorbed by the atmosphere wouldn’t it?(With a similar effect at night for outgoing radiation)

Robert Ellison says:
January 11, 2011 at 4:24 am
G’day Bruce,
Can I be a hemispherist? Can’t be bothered with the Northern Hemisphere at all – the main climate game is in the south.

Erl grows grapes and makes wine – in Australia.
Erl, this is brilliant. Your ideas are so much more accessible in this article than before, and it benefits from not trying to fit too much in at once. Well done!
I look forward to your exposition of the next link in the chain of causation.

John Johnston says:
January 11, 2011 at 12:48 am
OT, but does anyone know what has happened to Spencer’s Latest Global Temps at http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps+002? For the last couple of days it has no message. I hope it hasn’t been nobbled.

The SST channel is working on the other satellite, and SST seems to be dropping to Jan 2008 levels pretty quickly…
http://discover.itsc.uah.edu/amsutemps and select sea surface from the drop-down

Thanks for the tip, tallbloke. Let’s see how UAT matches up (when it comes back). It will be harder for AGWangers to challenge, being less affected by surface interference.

TomRude

Here is my best shot:
There are four factors contributing
1. Warm air descends from the stratosphere. As soon as the AO goes negative we see a geopotential height anomaly appear at latitudes higher than 60°north representing ozone rich air that absorbs long wave radiation from the Earth. There is no UV to be had in the polar night. So the source air in the descending polar circulation is warmer. It represents air slipping down through the ozone profile with more above and less below.
2 The warmed source air is further warmed as it descends via compression. In the polar regions, during the polar night, the air at the surface is warmer that the surface itself.
3 As Tom Rude points out in the last Arctic Ice thread: ” at the front of the high pressure anticyclones that brought cold and froze lemon trees in Florida the strong temperature gradient will force the advection of a huge amount of warm and moist air northward, that very same air that dumped snowmaggedon on the NE USA recently.”
4. All forms of precipitation release latent heat.
++++
I maintain No.3 but cannot accept No.1 and 2.

Chris H

I too watched the joke programme on Horizon last night. The theme was precision in environmental temperature measurement and his Stevenson screen was sited on the black asphalt roof that covered his apartment! Clearly never heard of radiated or reflected heat nor about UHI.

Mike Haseler

It’s all outlined here … now I’m a believer!
[youtube=http://www.youtube.com/watch?v=cdxaxJNs15s&fs=1&hl=en_US]

Dave Springer

Geoff Sherrington says:
January 11, 2011 at 2:00 am
“There is a lot of energy required to change those baro pressures. From where does it originate?”
The sun.

Dave Springer

Geoff Sharp says:
January 11, 2011 at 3:08 am
“It is also early days as the Sun refuses to kick start….I am starting to feel very uneasy.”
Virgins are getting skittish too.

Neil Jones

To kzb says:
January 11, 2011 at 4:34 am
However, it is clear that this person was actually the “ring leader”, acting to plan, motivate and facilitate so-called direct action, such as invading a power station site ! How many other climate protests are actually instigated by state agents we ask ?!”
Fair question but we could turn it on its head and ask “Was this an Environmentalist penetrating the police?”

Sean

I’ve been following Earl Happ for a couple of years now. I am a little surprised he did not include a solar connection in some of the polar oscillations. I thins he has some interesting insights in this topical area as well.

Pamela Gray

Erl says: “I can not imagine any internal dynamic that would produce a swing in Antarctic sea level pressure over 100 years. But I am aware of an external influence that does vary on 100 year time scales.”
This little event hasn’t been researched as it should. It is unknown as to whether or not this thing has more than a decadal signature (just about all that is known is that it takes 8 to 10 years to work itself around the SH). Could it be a cause or an affect that might help clarify your question?
http://www-das.uwyo.edu/~geerts/cwx/notes/chap11/ant_wave.html

RR Kampen

What is the statistical significance of found trends?

Alan the Brit

Very interesting post. Well done.
kzb says:
January 11, 2011 at 4:34 am
Saw the last half of it only, was anxious to see it all to see if as normal the Beeb slip in the old AGW chestnut into the fire but was out singing (all that CO2 exhalation is good for the soul). I was also interested about the siting of his temperature measuring equipment on the roof of his apartment. I didn’t hear any reference about contamination of any readings taken thro UHI & all that asphalt surrounding the site, but the PC female meteorologist dropped a few hints about the future & measuring temperatures in cities bing important stuff, etc. Nothing surprising of course but some generally interesting bits & pieces.

“Let us imagine that a ( mysterious) force that is capable of shifting atmospheric mass away from the poles and towards the equator”
Part of the answer may be in the behavior of the polar vortices.
http://en.wikipedia.org/wiki/Polar_vortex
Click on this link and then click on “Physical Overview” on the page to view a vortex animation:
http://www.cfm.brown.edu/people/sean/Vortex/
Here’s an animation of the currently broken up Antarctic Polar Vortex;
http://www.cpc.ncep.noaa.gov/products/intraseasonal/z500_sh_anim.shtml
and here’s an animation of the currently broken up Arctic Polar Vortex:
http://www.cpc.ncep.noaa.gov/products/intraseasonal/z500_nh_anim.shtml
A key measure of the vortices appears to be when they breakdown each year. According to this paper on the Final Warming Date of the Antarctic Polar Vortex and Influences on its Interannual Variability;
http://findarticles.com/p/articles/mi_7598/is_20091115/ai_n42654411/
“several studies (including Waugh and Randel 1999; Waugh et al. 1999; Karpetchko et al. 2005; Black and McDaniel 2007) have indicated a trend over the 1980s and 1990s toward a later vortex breakdown.”
This is a good paper exploring the Polar Vortices;
http://www.columbia.edu/~lmp/paps/waugh+polvani-PlumbFestVolume-2010.pdf
and the chart on page 10 shows the vortex break-up dates for the Northern Hemisphere since 1960 and Southern Hemisphere since 1979. Note that there appears to be a bit of disagreement in the literature as to whether the vortices break-up or breakdown, but either way, when it occurs, it likely has a significant impact on Earth’s atmospheric oscillations.
Does anyone know where to find historical data on the Polar Vortices, e.g. size, strength, shape, break up/down dates, etc.?

Jeremy

Off-topic question: If the stratosphere is part of a descending mass of atmosphere creating a local high-pressure, and the Antarctic generally has the highest pressure on the planet; and the ozone-layer is mostly located in the lower stratosphere… wouldn’t the best explanation for the Antarctic ozone “hole” be the result of a local high pressure continually forming/reforming in that area causing the lower part of the stratosphere to descend and mix with the lower levels of atmosphere?
It makes me want to go spray some CFC’s.

R. Gates

Wow Erl, fantastic post. Using the expression, “food for thought”, you’ve just provided me with a huge steak dinner! But being a vegetarian “warmist”, I’ll need to take this in little bite sized pieces.
Nice job…

JKS

Thoughts and prayers go out to the flood victims in Australia and their families and friends.

DanDaly

Might the decreased solar wind and associated collapse of the outer atmosphere have something to do with increased pressure at the north pole?

David L. Hagen

Thanks Earl, very interesting.
See the correlations found by WJR Alexander between precipitation/runoff in Southern Africa vs the 21 year Hale (double) solar cycle.
Linkages between solar activity, climate predictability and water resource development
J. So. African Inst. Civil Engineering Vol 49 No 2, June 2007, Pages 32–44, Paper 659
http://nzclimatescience.net/images/PDFs/alexander2707.pdf
May I encourage you to compare your pressure and oscillation indices etc. against the 21 year Hale solar cycles. By eye I see some possible correlations.

c1ue

Mr. Happ,
Thank you for your work.
It may again show how interested and objective observers are able to contribute materially to the progression of knowledge.
Your unusual focus on pressure is another avenue by which the ‘consensus’ may be missing the mark of reality.
Keep up the good work!

DonS

Very cool. Grapes as proxies for the activities of the AO, mid latitude atmospheric pressure and the attendant consequences. It was ever thus with all crops. Put away the play stations.
Just one thing: ” It is their WANT to consider the atmosphere as a…; should be “wont”. Sorry to be all englishy, but have been reading political blog comments and just couldn’t take one more misuse.

R. de Haan

A real clear example of thinking out of the box.
Great post.

Excellent explanation Anthony. Another puzzle piece. This work is another in the series of regional or zonal examination. It has always seemed to me that trying to represent anything as dynamic as global sized fluid systems with one or two oversimplified numbers is misleading at best and dishonest at worst. Having lived most of my adult life in what I call the subarctic (between 55 and 60N) your explanations match my general experience.

Alchemy

Very thought-provoking, and a line of inquiry I would like to see pursued by others.
On a slightly related note, I heard today a scientist discuss how the debunking of the UK doctor’s MMR vaccine study causing autism has not, in fact, stopped his supporters from claiming, despite years of studies to the contrary, that vaccinating children is evil/poisonous and that it’s probably why Johnny can’t think.
The scientist in question noted that in some cases, the reduction of child vaccination rates has fallen to 60-70%, meaning the loss of “herd immunity”, which requires a 95% “buy in”, and the resurgence of certain diseases kept more or less at bay for 50 years.
I was reminded that the “herd mentality” of some climate scientists seems to be making them immune to either counter-arguments, or to the pursuit of novel lines of research that might allow them to better model planetary climatic changes without making stuff up to suit preconceived notions. Me, I’ve seen changes in my life, but I am far from accepting the explanations for those changes, and thus cannot credence some of the prescriptions.

R. Gates

Geoff Sherrington says:
January 11, 2011 at 2:00 am
Stupid, fundamental question follows. Why does the atmospheric pressure not settle at an equilibrium, or at least a more steady pattern that follows insolation? There is a lot of energy required to change those baro pressures. From where does it originate?
_____
Look up, but don’t stare or you’ll go blind.

That southern hemisphere cooling is very interesting and entirely ignored by the climate establishment. As to the northern hemisphere, we have had arctic warming since the twentieth century started and it is still going strong. It is AGW but warm currents melting the ice. What it may or may not have to do with AO is quite unknown. I personally don’t trust oscillations that are poorly defined and whose full period has not even been observed. The only real oscillation worthy of the name is ENSO. It is an actual oscillation of ocean water from shore to shore, even if the “shore” in the west is porous and lets some water escape.

Typo correction: “It is not AGW.. ” (word not was left out)

Pat Frank

Here’s a little on-topic California dreamin’
The latest severe weather report:
“Statement as of 3:55 PM PST on January 10, 2011
“… Record minimum temperature at Sonoma County Airport…
“a record minimum temperature of 25 degrees was recorded at Sonoma
County Airport this morning. This breaks the old record of 28
degrees set in 2009.”

Following the Idso’s, ‘Not much global warming here!’

Robert Ellison

tallbloke says:
January 11, 2011 at 4:59 am
‘Erl grows grapes and makes wine – in Australia.’
G’day Bruce? Sorry – it was an in joke from the Philosophy Department of the University of Wooloomoolooo.
The long term changes in Polar pressures in both the Southern and Northern Hemisphere in large part seem to be related to changes in solar UV – which changes a lot more than radiance. UV changes result in warming and cooling of ozone in the upper atmosphere – hence top down forcing.
Cheers
Robert

Engchamp

What amazes me about the science of climate is that on almost every occasion that I log on to WUWT, there is something new to be learned, which has hardly been discussed. Here is a prime example in Erl’s illuminating post.
I have commented before on the complexity of this science, and I think I can safely say that the number of people that understand (and can explain) the picture in its entirety are numbered as being possibly less than the digits of your hands.
There is always another tint to add to the myriad colours.

Erl:
I don’t like giving someone who has ALREADY DONE significant work, more work! However, could you “normalize” the data in Figure 2., then run a “correlation coeficient” between the two data sets and see what value you get?
It would be interesting if it is a .7, or .8..
Max
PS: I have to make this disclaimer…”Correlation is NOT causation”….

Engchamp says: January 11, 2011 at 12:34 pm
“I have commented before on the complexity of this science, and I think I can safely say that the number of people that understand (and can explain) the picture in its entirety are numbered as being possibly less than the digits of your hands.”
I have to disagree with you there. Based upon everything I’ve read, heard and seen “I think I can safely say that the number of people that understand (and can explain) the picture in its entirety are numbered” zero…

Paul Vaughan

To get a better handle on what Erl is driving at, see Figure 3 & Table 3 (true gems) here:
Trenberth, K.E.; Stepaniak, D.P.; & Smith, L. (2005). Interannual variability of patterns of atmospheric mass distribution. Journal of Climate 18, 2812-2825.
http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/massEteleconnJC.pdf

Paul Vaughan

Judith Curry recently [ http://judithcurry.com/2011/01/04/scenarios-2010-2040-part-iii-climate-shifts/ ] encouraged readers to think about NPGO.
Di Lorenzo, E.; Schneider, N.; Cobb, K.M.; Franks, P.J.S.; Chhak, K.; Miller, A.J.; McWilliams, J.C.; Bograd, S.J.; Arango, H.; Curchitser, E.; Powell, T.M.; & Riviere, P. (2008). North Pacific Gyre Oscillation links ocean climate and ecosystem change. Geophysical Research Letters 35, L08607. doi:10.1029/2007GL032838.
http://horizon.ucsd.edu/miller/download/NPGO/NPGO.pdf
NPGO data:
http://www.ocean3d.org/npgo
I spent some time getting a bit of a handle on how NPGO relates to other indices, such as SOI, El Nino Modoki index, PNA, NPI, PDO, etc. Then I looked at NPGO’ (rate of change). It was immediately apparent that there was periodicity. A closer look revealed harmonics of polar motion (harmonics of 6.41 years) & phase reversals. This was interesting, as the same harmonics show up in local weather records for coastal British Columbia.
For anyone looking into this, pay attention not only to means, but also variance (and realize that annual timescale variance exists in anomaly data even though a cycling mean has been subtracted).