Something topical

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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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70 thoughts on “Something topical

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

  2. 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?

  3. 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

  4. 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.

  5. 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?

  6. 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

  7. 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.

  8. 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 ?

  9. 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.

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

  11. 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)

  12. 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.

  13. 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

  14. 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 ?!

  15. 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)

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  21. 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.

  22. 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.

  23. 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?”

  24. 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.

  25. 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

  26. 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.

  27. “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.?

  28. 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.

  29. 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…

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

  31. 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.

  32. 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!

  33. 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.

  34. 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.

  35. 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.

  36. 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.

  37. 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.

  38. 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!’

  39. 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

  40. 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.

  41. 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”….

  42. 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…

  43. 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).

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

    Many thanks Erl.

    I came across the following document yesterday, haven’t read it yet, but it might have some useful data : “Influence of Solar Activity Cycles on Earth’s Climate – Final Report”, Danish National Space Center 2007, 134 pages.

    There are sections on solar influence on winds, stratospheric ozone, atmospheric jets, atmospheric ionisation, and mechanisms of stratosphere-troposphere coupling .

  45. I hope it’s ok to quote the conclusions of the DNSC’s 2007 report (this might be stretching the definition of “brief quotation” – a full citation is provided below, though):

    Conclusions

    The Sun:
    • Sunspot number catches only part of solar activity
    • The Sun’s magnetic field drives short term changes
    • Use therefore magnetic data for Sun-Climate studies
    • Solar output predictability is at most years ahead
    • Due to the complexity and time-varying nature of the Sun solar-climate coupling
    must be expected to be very complex and probably changing with time

    Correlations:
    • The overall solar cycle dominates solar-climate correlations.
    • Statistically robust signals of the impact of solar variability have been detected
    throughout the stratosphere and troposphere in temperature, wind and atmospheric
    circulation. These include, when the Sun is more active,:
    o a warming of the upper and lower stratosphere in low-to-middle latitudes
    o a strengthening of the winter stratospheric polar night jet
    o vertical bands of warming in the mid-latitude troposphere
    o a weakening and poleward expansion of the tropical Hadley cells and a
    poleward shift of the Ferrel cells
    o a more positive tendency of the North Atlantic Oscillation
    o the solar signal in stratospheric temperatures and in the tropospheric polar
    modes of variability is modulated by the phase of the quasi-biennial
    oscillation
    • Direct heating by absorption of solar ultraviolet radiation can explain most of the
    temperature response in the upper stratosphere but not the signals in the lower
    stratosphere and troposphere.
    • When removing the solar cycle the most robust tropospheric correlations are seen
    with UV and cosmic rays.
    • UV and GCR show negative(positive) bands of correlations with low clouds at
    mid-to-high latitudes. These bands are strengthened by removal of the solar cycle.
    • On the surface only rather weak correlations are observed. This is to some extent
    due to the short time span of the available parameters such as the NDVI
    (vegetation), snow and ice data.
    • At solar min/max a zonally averaged temperatures under solar max/min
    conditions show a negative/positive correlation with UV in the troposphere and
    similar, but with opposite sign with GCR.

    Mechanisms, Models and Methods
    • Correlation studies inherently assume a linear response to changes in forcing
    parameters. Any non-linear behaviour of the climate system is bound to cause
    problems.
    • There are serious discrepancies between the solar signal in stratospheric ozone
    derived from satellite measurements and that suggested by chemistry-climate
    models.
    • Uncertainty in the ozone signal also implies uncertainty in the value of solar
    radiative forcing of the troposphere.
    • Some of the ozone discrepancy may be related to inadequate treatment in the
    models of the effects of solar energetic particles but these are unlikely to explain
    the ozone minimum shown in the tropical middle stratosphere.
    • Solar signals near the tropical stratopause can be transmitted to the polar and
    tropical lower stratosphere through mechanisms involving wave-mean flow
    interactions.
    • Perturbations to the winter stratospheric polar vortex appear to propagate
    downwards into the troposphere although the mechanisms involved are not clear.
    • Heating of the tropical lower stratosphere can influence the temperature, wind and
    circulation of the troposphere through dynamical coupling that appears to depend
    on perturbing the behaviour of synoptic-scale eddies.

    Danish National Space Center Scientific Report 2/2007, “Influence of Solar Activity Cycles on Earth’s Climate” Freddy Christiansen, Joanna D. Haigh, and Henrik Lundstedt (ISBN-10: 87-91694-12-4)

  46. Just a supposition here, but the 60+ year oscillation cycle of the AO (from peak to peak) appears to me to be a natural harmonic of the yearly tilt of the earth back and forth. Just as an out of balance tire spinning a different speeds can produce less or more vibration (harmonic sympathetic vibrations) so too could our atmosphere (which though it is a gas, still behaves with some of the properties of a liquid being stirred) be slowly responding en masse to the rocking of the Earth.

    RE-the Sun’s output and cycle… As a driver of WEATHER it is unparalleled and may also play upon the natural harmonic of the Earth BUT, the tilting of the Earth is a relatively stable cycle. Summer and Winter Solstices occur on the same date each year, right? It may just be that the AO is an atmospheric harmonic on a fixed cycle, with the relative strength of the cycle being modified by where the Sun is at in it’s roughly 11-year cycle. We certainly know from the Maunder Minimum and Dalton Minimum of the effect of the Sun as a driver of seasonal high and low temperatures over extend periods of year, but temperature alone is not climate. Explaining how the AO affects hemispherical air pressures could go a long way towards our understanding of “climate”.

    My bigger concern is this; why is it impossible for climate scientists to tell us exactly how an ice age comes about? If the ice ages have been relatively consistent over the last 3 million years, then what is their driver? Are they a much broader harmonic also related to the short-frequency harmonic of the AO, all driven by the rocking of the Earth? Or is the output of the Sun itself on a cosmic oscillation time-scale? Given that there’s no other good explanation so far, my bet’s on the Sun!

    And who will be the first government to ban the Earth’s tilt in the interest of Global Climate Security of all of humanity? LOL (That’s scarcasm in case anyone missed it)

  47. Very nice, Erl, except for just this one part:

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

    Erl, correlate isn’t quite the right word. Both sets of data seem to be normalized (mathematically forced to vary about an average of zero), so of course they’re both going to fall near the zero line. There’s not much trend, either, so they’re both flat, too. That is evidence of coincīdence or congruity, not correlation. If they ARE truly correlated, please give us the correlation coefficient, making the necessary correction for autocorrelation. Otherwise, just strike that part. I don’t think it’s a major part of your post. Thanks, Jorge.

  48. Re: Eric Eikenberry

    Sounds like you’re thinking towards what I wrote here:
    a) http://judithcurry.com/2011/01/04/scenarios-2010-2040-part-iii-climate-shifts/#comment-28348
    b) http://judithcurry.com/2011/01/04/scenarios-2010-2040-part-iii-climate-shifts/#comment-29659
    [SCL’ = rate of change of solar cycle length, which can alternately be conceptualized as solar cycle deceleration. There is a ratcheting across terrestrial seasons, QBO phase, etc. which is not independent of variables such as summer-winter SOI contrast.]

    Elaboration:
    1) http://wattsupwiththat.com/2010/08/18/solar-terrestrial-coincidence/
    2) http://wattsupwiththat.com/2010/09/04/the-north-pacific-solar-cycle-change/
    3) http://wattsupwiththat.com/2010/09/11/solar-cycle-length-its-rate-of-change-the-northern-hemisphere/
    4) http://wattsupwiththat.com/2010/10/11/atlantic-hurricanes-the-sun/

    Similar articles could have been written on All India Rainfall Index & other variables. I didn’t bother because the audience didn’t have enough of a handle on interannual variations to understand. (Hence my current focus on the spatiotemporal aspects of interannual variations to try to develop summary methods that will empower audiences to overcome multiscale-cognition barriers.)

    Erl is focusing our attention on mass distribution for good reasons.

  49. Hey everyone. Sorry but I didn’t know this was coming up. I am at the wrong end of an internet connection that keeps dropping out. Add to that a day out in the sun applying nets to vines under a hot sun.

    Thanks for a lot of links that I will be keen to pursue next weekend. Sorry about my inability to respond at the moment. This post was intended to get you thinking. There are three more in the pipeline. One is in review so it could come soon. Another written but yet to be put into wordpress and a third in draft. So, there will be plenty of discussion to come.

    Briefly:
    Paul Vaughan
    Erl, I challenge you to summarize the mirror image pattern in a single color-contour plot. If you succeed, this should attract considerable interest.
    Post after next Paul
    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?
    The atmosphere is in part an electromagnetic medium. I have a post coming up on this.
    stephen richards says:
    January 11, 2011 at 3:05 am
    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
    I see 1978 as pivotal.
    Pamela Gray says:
    January 11, 2011 at 6:29 am
    I have not been aware of this wave.
    Just The Facts says:
    January 11, 2011 at 7:11 am
    I will check out those references. Thanks, looks like useful stuff.
    DanDaly says:
    January 11, 2011 at 8:24 am
    Yes
    Max Hugoson says:
    January 11, 2011 at 2:17 pm
    Max, it wouldn’t worry me if the coefficient was less than significant. Both poles influence the result and they don’t always work together….in fact they are most potent in their respective winters.
    jorgekafkazar says:
    January 12, 2011 at 12:16 am
    See response to Max Hugoson

    Got to go drop some marron nets in a dam with the grandson. I promised.

  50. Tom Rude,
    Not sure whether you are indicating different interpretaion in general or just disagreeing with my notion of why Greenland warms.
    Can you give me an explanation of what happens in the stratopshere when the AO goes negative?
    In particular what is it that produces the GPH anomaly over Greeenland and the north east Pacific? See:
    1. http://www.cpc.ncep.noaa.gov/products/intraseasonal/z500_nh_anim.shtml
    2. http://www.cpc.ncep.noaa.gov/products/intraseasonal/z200anim.shtml
    3. http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/hgt.shtml

    And which way is this air moving? Is it descending?

  51. Robert Ellison
    You say: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.

    Any documentation? First I have seen of this.Can’t think how it could possibly work.

  52. Robert Ellison
    Re:Lockwood, M., Harrison, R., Woollings, T. Solanki, S., (2010) Are cold winters in Europe associated with low solar activity?

    Perfectly consistent with what I am saying. Difference is Lockwood has not worked out what the mechanism is. Has the correlation between the NAO and geomagnetic activity down pat but no idea of the cause.

  53. Robert
    I am sure that the polar oscillations (plural) are driving the change in tropical and mid latitude sea surface temperature and the latter is the most reactive because the cloud cover is denser there.

    UV plays a role in all this but a minor one. The atmosphere is an electromagnetic medium that responds to the solar wind. The response is greater when neutrals and ionized particles are most intimate….i.e. when UV is least intense.

  54. I want to thank all those who took the trouble to comment and indeed I am encouraged by the number of people who were complimentary.

    I do have a tendency to try and explain too much at once. In his post I tried to keep the focus as tight as possible. I guess it helped. Necessarily however, the big picture has to wait.

    Another Gareth says:
    January 11, 2011 at 4:38 am

    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)

    Agreed, but not sure how it might affect surface climate.

    Just the facts
    Agreed, polar vortices are worthy of the closest study. I think it an area that is poorly understood.

    DanDaly says:

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

    Indeed. But the thing is to get the data to show this is a consistent relationship.

    David L. Hagen
    Thanks for the recommendation. I read these papers a while ago. I woulod be keen to hear about the relationships that you see.

    Dennis Nikols, P. Geol.
    As a person living in a very different environment it is a comfort to hear that what I say matches your experience. One is always on dangerous ground dealing with the unfamiliar.

    Arno Arrak
    The cooling was at 30-50 north latitude. Not in the southern hemsiphere.

    oneuniverse
    Thanks for the reference. Have looked at it before. Its an exhaustive analysis.

    “Direct heating by absorption of solar ultraviolet radiation can explain most of the
    temperature response in the upper stratosphere but not the signals in the lower
    stratosphere and troposphere.” A critical observation with which I agree.

    “Perturbations to the winter stratospheric polar vortex appear to propagate
    downwards into the troposphere although the mechanisms involved are not clear.”

    I want to make that abundantly clear. There is no area of climate science where there is so much bull as this one.

    Just The Facts
    “Off topic, can anyone offer any insight as to potential sources of the large temperature anomaly that recently developed in the stratosphere over Asia?”

    Its actually right on topic. Cause is a fall in the AO. Rising polar pressure coincides with accelerated downward movement of polar air. Its loaded with ozone and ozone absorbs outgoing long wave radiation from the earth.

    jorgekafkazar
    There is a cause and effect involved. Wait for it.

  55. Re: jorgekafkazar

    Jorge, Erl is talking about complex correlation in the sense described:

    a) in comments by Tomas Milanovic here [ http://judithcurry.com/2011/01/04/scenarios-2010-2040-part-iii-climate-shifts/#comment-28100 ], where he is discussing the following paper:

    Tsonis, A.A.; Swanson, K.; & Kravtsov, S. (2007). A new dynamical mechanism for major climate shifts. Geophysical Research Letters 34, L13705.

    http://www.uwm.edu/~aatsonis/2007GL030288.pdf

    b) here:

    Schwing, F.B.; Jiang, J.; & Mendelssohn, R. (2003). Coherency of multi-scale abrupt changes between the NAO, NPI, and PDO. Geophysical Research Letters 30(7), 1406. doi:10.1029/2002GL016535.

    http://www.spaceweather.ac.cn/publication/jgrs/2003/Geophysical_Research_Letters/2002GL016535.pdf

    Note that in later comments here, Tomas Milanovic adds that:

    “If Tsonis is right in the sense that his observation holds, then ALL climate models without exception are completely wrong. [...] This proves that if Tsonis is right then the models miss something essential.”

  56. Erl,

    “Robert Ellison
    You say: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.

    Any documentation? First I have seen of this.Can’t think how it could possibly work.”

    Apparently during periods of high solar activity the Sun emits substantially more UV than during quieter periods, which would directly affect the ozone layer — which is densest over the poles. Also, according to this paper, UV has been increasing since the Little Ice Age much more than TSI (“Reconstruction of solar spectral irradiance since the Maunder minimum” at http://www.mps.mpg.de/projects/sun-climate/papers/uvmm-2col.pdf) –

    Here we reconstruct solar total and spectral irradiance in the range 115–160 000 nm since 1610. The evolution of the solar photospheric magnetic flux, which is a central input to the model, is appraised from the historical record of the sunspot number using a simple, but consistent physical model. The model predicts an increase of 1.25 W/m2 , or about 0.09%, in the 11-yr averaged solar total irradiance since the Maunder minimum. Also, irradiance in individual spectral intervals has generally increased during the last 4 centuries, the magnitude of the trend being higher towards shorter wavelengths. In particular, the 11-yr averaged Ly- irradiance has increased by almost 50%.

    An exception is the spectral interval between about 1500 and 2500 nm, where irradiance has slightly decreased (by about 0.02%).

  57. Erl responded to Pamela Gray‘s link to a webpage featuring the cycle of ACW loading patterns, “I have not been aware of this wave.”

    Erl see also the SH VEOF4 wave-3 pattern that corresponds with the NH wave-1 NPI pattern to which I have drawn attention above.

    Note also the speculation of Schwing, Jiang, & Mendelssohn (2003) (to which I linked above):

    “Multidecadal climate variability in the north Pacific atmosphere and ocean is strongly coupled. However the atmospheric teleconnection between the north Atlantic and north Pacific, while connected, appears to have multiple modes. While atmospheric variations often occur in characteristic standing wave patterns [...], they can change in orientation and give the appearance of propagation [...], and change in wavelength and frequency. An oscillation in the standing wave patterns would lead to the abrupt changes in the indices described here. We suggest that the fundamental atmospheric wave number varies on decadal scales, and switched from a pattern where the Atlantic and Pacific were in phase prior to 1957, but out of phase during 1962–1988.” [my emphasis italicized]

    My investigations using multiscale complex correlation algorithms (which I have developed from scratch independently) reveal that such switching occurs on more timescales than just decadal (e.g. interannual, with absolute certainty – & showing intermittent persistent coherence with interannual variations of solar variables such as B & V [which are NOT to be confused with decadal irradiance]).

    A more recent paper by Warren White (who pioneered ACW knowledge):

    White, W.B.; & Liu, Z. (2008). Non-linear alignment of El Nino to the 11-yr solar cycle. Geophysical Research Letters 35, L19607. doi:10.1029/2008GL034831.

    https://www.cfa.harvard.edu/~wsoon/RoddamNarasimha-SolarENSOISM-09-d/WhiteLiu08-SolarHarmonics+ENSO.pdf

    I suspect that he &/or others will modify the formulation moving forward, but the paper is stimulating as is.

  58. We sometimes have blinders on and see things as always happening from the top down and from left to right. Education does that to us. But consider this: The stratosphere’s influence on our climate has two sources that can influence it to then change the temperatures down here. It can be influenced from above AND from below. Disturbances in the troposphere, caused by the undulating, oscillating, ever swirling, ever changing planet we live on, can disturb the stratosphere which in turn can propagate that disturbance downwards again.

    Any search for influential drivers must commence on both sides of this fascinating, ethereal layer. And before we run to quickly to the Sun, I think we should at least thoroughly understand the closest source of influence before reaching out to more distant drivers of weather pattern VARIATION.

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