The Trade Winds Drive The ENSO

Bill, that is just eye candy to this weather nut. I wonder if these winds are set up by Earth rotation? Would the Terra firma spin faster than the atmosphere at the equator, thus making it seem like the wind is blowing from East to West instead of West to East in concert with Earth’s rotation direction? And then maybe viscosity of the atmosphere makes the trade winds strong or weak?

Thanks Bill. You make it beautifully clear.
It would be interesting to know that the ENSO contribution to the global anomaly is. The billion dollar question is: What number of El Nino degrees C were part of the 1998 peak. If the models didn’t include this, then they would have concluded that too much of the warming was man made.

“Who would have thought that Winds in some small region of the Globe could be so important.”
M. Ghil et al. / Physica D 237 (2008) 2111–2126
Climate dynamics and fluid mechanics: Natural variability
and related uncertainties
Abstract
The purpose of this review-and-research paper is twofold: (i) to review the role played in climate dynamics by fluid-dynamical models; and (ii) to contribute to the understanding and reduction of the uncertainties in future climate-change projections. To illustrate the first point, we review recent theoretical advances in studying the wind-driven circulation of the oceans. In doing so, we concentrate on the large-scale, wind-driven flow of the mid-latitude oceans, which is dominated by the presence of a larger, anticyclonic and a smaller, cyclonic gyre. The two gyres share the eastward extension of western boundary currents, such as the Gulf Stream or Kuroshio, and are induced by the shear in the winds that cross
the respective ocean basins. The boundary currents and eastward jets carry substantial amounts of heat and momentum, and thus contribute in a
crucial way to Earth’s climate, and to changes therein.
Changes in this double-gyre circulation occur from year to year and decade to decade. We study this low-frequency variability of the winddriven, double-gyre circulation in mid-latitude ocean basins, via the bifurcation sequence that leads from steady states through periodic solutions and on to the chaotic, irregular flows documented in the observations. This sequence involves local, pitchfork and Hopf bifurcations, as well as global, homoclinic ones.
The natural climate variability induced by the low-frequency variability of the ocean circulation is but one of the causes of uncertainties in climate projections. The range of these uncertainties has barely decreased, or even increased, over the last three decades. Another major cause of such uncertainties could reside in the structural instability – in the classical, topological sense – of the equations governing climate dynamics, including but not restricted to those of atmospheric and ocean dynamics.
We propose a novel approach to understand, and possibly reduce, these uncertainties, based on the concepts and methods of random dynamical
systems theory. The idea is to compare the climate simulations of distinct general circulation models (GCMs) used in climate projections, by applying stochastic-conjugacy methods and thus perform a stochastic classification of GCM families. This approach is particularly appropriate given recent interest in stochastic parametrization of subgrid-scale processes in GCMs.
As a very first step in this direction, we study the behavior of the Arnol’d family of circle maps in the presence of noise. The maps’ fine-grained resonant landscape is smoothed by the noise, thus permitting their coarse-grained classification.”
This is a very important paper in terms of our understanding of atmospheric -ocean circulation coupling.IE it increases our understanding of the fluctuation theorem.

Pamela,
The E to W direction of the dominant winds near the equator is a result of the coriolis force, a component of Earth’s gravitation, which is indeed due to the planet’s rotation. The coriolis effect makes large moving masses of air deviate to the right in the northern hemisphere and to the left in the southern hemisphere. Air moves from the tropics toward the equator to replace the hot air ascending over the latter. On their way to the south and the north, the coriolis effect makes the air masses deviate to the right and the left in the northern and southern hemispheres respectively, hence the north-easterly and south-easterly trade winds. Near the equator, these masses meet along an east-to-west course. Over the equator itself, there is a belt of unstable air with little wind; these are the so-called doldrums where sailships could get caught up in windless air for long periods at a time. The coriolis effect is also responsible for setting up the rotation in developing cyclones (anticlockwise in the northern hemisphere, clockwise in the south).
Bill,
Great stuff. I had often wondered about the band of contra-rotating vortices one sees develop over the equator in the SST anomaly plots, as in the animation you link to (particularly well-developed in the 12/29-31/2008 frames). These imply rather fast-moving (relatively speaking) masses of water, which might well be “driven” by stronger-than-average trade winds. This could be checked by comparing the strength of these vortices in the SST anomaly frames over time against the strength of the trade winds.
BTW

another debunking of Steig’s paper at Lucia’s blog ?
http://rankexploits.com/musings/2009/steigs-antarctica-part-three-creative-mathemagic/

Or: Both the ENSO and the tradewinds are driven by a third, as yet unidentified mechanism, and therefore vary in tandem … ?

Quick question (not ment as critique). Since correlation does not imply causality, could it not be the other way around? That the ENSO is driving the wind? From eyeballing the figures, it seems as if the trade winds are lagging the ENSO just slightly. Can I suggest that you do a phase analysis of the two signals? That should resolve the question.

It sounds completely convincing to me. The lags etc. may indicate that the winds are the cause and ENSO is the effect – unless it’s the other way around, of course. Still, I would like to know why the trade winds oscillate in intensity. They may be “more elementary” than the temperature indices but they’re still not making things predictive.

I think it is more likely that the tradewind and the ocean current have the same cause. The kinetic energy of the upper ten meters of ocean are the same as for the whole atmosphere above, and they only touch each other on one surface. Correct me if I am wrong.
How about comparing ENSO with the moons apogee and perigee and its position relative to the equator, together with aphelion and perihelion of earth?
If the moon in its perigee is north of the equator and in the apogee south, it would have e greater effect on the east2west currents and winds on the souhtern hemisphere. With the earth at aphelion at the same time, it would amplify this effect.
I can’t find data or a simulation program on the net for this, or what to look for. I only found that we are closest to the sun a few days after newyear.

Some interesting stuff on the subject here
Annular Mode
A hemispheric-scale circulation pattern defined by changes in the westerly winds at midlatitudes. Those winds arise from the temperature contrast between the tropics and polar regions. The annular modes see-saw between positive and negative phases in what’s called a dipole pattern for weeks or months and take a circular shape (annular means ring-shaped). The two major types are the Northern Annular Mode (also called the Arctic Oscillation and strongly related to the North Atlantic Oscillation) and the Southern Annular Mode (also called the Antarctic Oscillation).
Circulation, Global
Energy from the Sun puts Earth’s atmosphere and oceans in motion. One reason is that solar radiation is not evenly distributed: the Sun hits the equator more directly than the poles, resulting in more heating in the tropics than at higher latitudes. In addition, the tilt on its axis that gives Earth its seasons results in a twice-yearly shift in the zone of maximum radiation: northward from December to June and southward from June to December.
Heated air rises above the tropics and flows toward the higher latitudes, where it cools, sinks, and flows back toward the tropics in an easterly (east to west) surface pattern known as the trade winds. This constant, overturning flow in the tropics is called the Hadley circulation.
Farther from the equator, Earth’s rotation combines with temperature contrasts between the tropics and polar regions to create midlatitude westerlies, along with cyclones and anticyclones, that move heat from the subtropics to higher latitudes. The warm fronts seen on weather maps are the leading edge of warm air pushing poleward, while cold fronts signal the flow of cold air toward the equator.
The oceans also redistribute heat via the thermohaline circulation, sometimes referred to as the ocean conveyor belt.
An introduction to atmospheric and ocean circulation, including explanations of pressure gradients and the Coriolis effect, for example, may be found on a University of Wisconsin Web site.

“The winds apparently affect the earths rotation, so I’m not so sure the rotation causes the winds…?
http://www.nasa.gov/centers/goddard/news/topstory/2003/0210rotation.html ”
The winds are created from high and low pressure cells, and that’s all caused from temperature differences related to the suns energy “influence” on the oceans/land and cyclical weather patterns. The only change for rotation is our bulging earth. Same rotation, just a bigger girth, adding one more second to our rotation this year( and more). Sea levels have been rising since the ice age, natural global warming the culprit.
It’s most ridicules to claim that AGW is now taking over for the SUN influences and when it comes to rises in seas levels (and temp). This has come to a stop or dropped for more then a few years.
Reason,
Expansion of our planet through planetary continental divide(seen on most planets) … of course caused by the sun/sun and planetary momentome magnetic forces.

We reside in the suns atmosphere and solar radiation varies between sun cycle peaks and troughs. Does the suns gravitational pull on the earth vary between solar maximum and solar minimum, which in turn affects the earths gravitation which in turn affects trade winds?

We’ve found that the upper ocean heat content is an even better leading indicator than trade winds. Check it out here:
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/weeklyenso/heat-last-year.gif

Thanks Bill for this – nice graphics, though we are still left with the question of what the ultimate driver is – winds respond to pressure differences, and pressure differences can result from warm/cold surface waters or….solar effects in the upper atmosphere. We shouldn’t forget that Landscheidt had a formula for solar timing that enabled him to predict El Nino in 1998 and 2002, as well as the current run of La Nina and neutral conditions.
Glenn – just looked at that paper from the Fluid Dynamics people at Princeton. Their work would repay closer study – wish I had the time! They claim to have a simulation that captures the ENSO oscillation and Walker cell slow-down and that it shows anthropogenic cause – i.e. that their models do not replicated the slow down unless they have an excess greenhouse gas component. From then on, in IPCC-speak, they take this as a proof of global warming theory. Of course the models only have a solar TSI component. The slow down is a century-long phenomenon – it would be instructive to have a break-down of its displacement in time – I bet that it is dominated by the 1980-2000 period and the 1998 super ENSO event – in which case, their explanation of the post-2002 stillstand on ocean heat content and recent la Nina would be interesting – though probably put down to random variability.
There tends to be a focus upon trends rather than cycles. And no talk of teleconnections. There is work on the phase interaction of the PDO and ENSO, with negative phases of the PDO dampening the amplitude of ENSO – which appears to be what we have now. Paleo-ecological studies (tree rings and sediment studies) show centennial cycles of ENSO intensity correlating with, for example, the Medieval Warm Period and Little Ice Age – thus implying a link with solar magnetic cycles.
I share your reaction, Glenn, to the all-too-ready statements that the slowing walker circulation demonstrates AGW when those researchers have no explanation for the obvious low frequency modulation of ENSO and the equally obvious correlation with the recent solar maximum. Their close ties to the IPCC are advertised in the paper. It smacks of self-fulfilling prophetic models.

Bill,
The 850MB level is closer to 5000ft rather than 3000ft.

OK. Now what drives the trade winds…

http://www.lavoisier.com.au/articles/greenhouse-science/solar-cycles/IanwilsonForum2008.pdf
Bill Illis,
Great work! You might be interested in a presentation that I gave
to the Lavoisier Society in July 2008. It can accessed at the link shown above.
Interesteingly, it is titled “which came forst, the chicken or the egg?”

As has been pointed out, “correlation does not imply causation”; even if ENSO lagged weakened Trade Winds, that would not imply the weakening of Trade Winds caused ENSO (or vice versa): it would be just as possible that a third (as yet unknown) phenomenon caused both with different lag times. All this just points to something to investigate further, not to any conclusion. Let’s not fall in the same trap most AGW believers do.
On the other hand, I am wondering why ENSO happens in the Pacific Ocean and not in the Atlantic or Indian Oceans; there are Trade Winds in all of them. Maybe the larger East-West size of the Pacific allows for the establishment of an oscillation, which would point to a geographical reason for it. Maybe an East-West temperature oscillation is a natural feature of any body of water with enough East-West equatorial size for it, and it just happens that under the current continental configuration only the Pacific is large enough.

Hmmm… FROM NOAA Feb 17th, SEE page 28:
“The CFS ensemble mean (heavy blue line) indicates La Niña ending during FMA 2009 with El Niño conditions developing by JJA 2009.”
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
Hmmm… El Nino June-July-August????
:p :p

My feeling at the moment, unless someone has a better idea, is that the initial causation may be a change in net warming or cooling of the air, as a whole, globally.
That would change the air circulation patterns resulting in the observed wind effect on the ocean surfaces but would itself have been caused by changes in the rate of release or absorption of energy from the ocean surfaces.
There seems to be some sort of interaction between the air circulation and the ocean circulation which changes depending on whether the oceans are globally warming the air or globally cooling it.
ENSO would be a major part of that interaction but would be modified in it’s effect by other variables such as solar input and the phases of the cycles in the other oceans.
The global warming trend or cooling trend in the air, initiated by the oceans, then leads on to all the variations in both circulations that seem to be causing so much puzzlement.

In terms of whether the ocean temps are, in fact, driving the Winds and not the other way around, I don’t think the data can’t really prove which drives which.
However, logic can. Sunlight absorbed by the water is the source of energy in the system (explained well by Bob Tisdale above) so it’s ocean temperatures that drive the winds. No doubt there is some feedback from the winds, but since the system is trying to balance an unequal distribution of energy it would make most sense to attribute the “driving” force to the location of the most energy (ocean, not air).

Let me see if I understand this correctly. The Trade Winds are caused by cooler air from higher latitudes moving to replace warmer air in the tropics that is ascending and this is influenced by coriolis force to move the air masses E to W in the Pacific. The result is the Trade Winds movement ‘dragging’ warm surface waters towards Asia, that water being replaced by cooler water from the depths off the coast of South America.
If this is true then would not the Trade Winds decrease in intensity if the temperature differential between the tropic and higher latitudes decrease? If so, if CO2 does heat the atmosphere in the higher latitudes then the result would be weaker trade winds and el Nino conditions?

Excellent piece of work Bill. Just another very inexpensive but sound piece of research that helps us realise just how much more there is to climate other than AGW. But when will these IPCC ‘scientists’ stop running computer codes and read such work?

And…do not forget taking into account that the people who named El Nino as such (the descendants of the Moche Culture people) blame the Sun for this phenomena CLICK
REPLY: Just type in the URL with the comment, don’t bother with tags – Anthony

Sorry, here is the link:CLICK

The CFS ensemble mean forecasts of Nino conditions are not very accurate. While they should be taken into account, the accuracy is pretty low.
The prediction (including the November forecasts) leading into this Nino season was for neutral conditions. A few weeks later and there is a La Nina.
The prediction as late as February 2007 was for just a 1% chance of a La Nina developing in 2007 and by the time the forecast had been published, the La Nina trend had already started.
I’ve been following the ENSO since I was very young when the 1982-83 super El Nino started to make the news. I haven’t noticed good predictive capability in the forecasts ahead of the events.
You can review the archive of the Nina predictions here.
http://www.cpc.ncep.noaa.gov/products/expert_assessment/ENSO_DD_archive.shtml

Hm. The Hypothesis of Marcel Leroux starts with what drives the trade winds. He registered ‘pulses’ in the trade winds and postulates that they are driven by Mobile Polar Highs (MPH) when they end up near the equator.
His book ‘Global Warming – Myth or Reality’ (ISBN-13: 978-3540239093) is a fascinating read. Try http://www.amazon.de/Global-Warming-Climatology-Springer-Environmental/dp/354023909X/ref=sr_1_1?ie=UTF8&s=books-intl-de&qid=1234969104&sr=8-1

Don’t overlook tallbloke’s comments above.
We know LOD varies continually, partly a function of seasonal distribution of ice mass and partly a function of variable magnetic coupling betwixt sun and earth.
We know that as the rotational rate derivative changes, angular momentum is transferred between solid and fluid (atmosphere and ocean). (GLAAM is a poor measure of this.)
From a consideration of physics alone, this must be A (probably THE) major driver of changes in the trades. But not the only driver, as Tisdale points out; this is a complex, chaotic system….a chaotic system that is easily modeled, of course, which is why our weather forecasts are so bloomin’ accurate.

Very informative on a mind-boggling subject. Nice job.

What you have here, is a complex system consisting of oscillators, inside oscillators inside oscillators. Each oscillator moving at its own natural resonate frequency, sometimes helping or hindering the larger oscillator it is part of and sometimes being aided or retarded by a junior oscillator which is a part of it.
For a thought experiment, lets suppose we could let the earth stabilize to an absolutely isothermal condition, then “turn on” the weather, sun etc. to let the drivers begin to drive the system. At some place somewhere on the plains of some continent, the local heating on one slope of a gentle valley would be more strongly heated by the sun than the opposite slope. The warmed air above the more favorably heated slope would start to move up slope due to heating, and the cooler air on the other side of the valley would start to sink. You now have a small convection cell, which would quietly circulate until it gets strong enough to lift the warm air column above condensation level and start to condense a cloud out. Since the sun is almost never directly over head the shadow of the cloud would cool another piece of ground(not under the main updraft) that used to be heated by the sun. That air would sink and then get pulled under the rising column of convection, adding more energy. Eventually you get a thunder storm which, develops a strong updraft and pulls in warm moist air to feed the storm. Then it suddenly dumps rain, cooling the ground below it and producing a strong cool down draft. That produces a cold outflow boundary which sweeps across 100 miles of terrain as it mixes with local air and warms back up. This kick starts other convection cells into full fledged thunder storms and the cycle continues for ever.
Each small perturbation in that isothermal earth would do the same thing. Over time some of those local systems join to feed each other or inhibit each other and then you have large scale circulations.
In short you have a chaotic system with uncountable numbers of inputs all trying to equalize some small imbalance of forces/effects (temperature, density, humidity, radiant heat loss, radiant heat gain). Some of these actions amplify near by motions others inhibit near by motions. Some build into large scale regional circulations, which in turn build into global scale circulations.
Likewise on a global scale you have stronger heating near the equator than higher latitudes due to the curvature of the earth and the angle of incidence of the suns rays causing differential heating from the equator to the poles. Then you have different albedo of surfaces (sometimes albedo that changes by time of day due to terrain slope and sun angle).
I think we can reasonably expect to identify the more dominant factors, but to think we can trace that chain of instabilities and oscillations down to their source is naive in my view. Due to clouds, differences in humidity, winds and lifting due to terrain, axial tilt, rotation of the earth, orbit around the sun, the conditions are never uniform and always trying to equalize something.
Bottom line you have the butterfly effect in action. Everything is triggered by everything else in some measure, and everything drives something else, like a mobius strip, you cannot find the end, as one driven element always will lead to another driver, which in turn is driven by yet another driver.
Stability in an electronic circuit is determined by the degree of feed back and its phase to the input, change the phase shift or the strength of the feed back or modify dampening (resistance) and the characteristic frequency of oscillation will change. If you get the feed backs small enough or negative you have a stable circuit, but even a stable circuit will ring if you hit it hard enough. It just will not ring very long.
The tradewinds, sea surface temperature, and build up of pools of warm water are all elements of the same oscillator. You change any of them, and you change all of them. At some level of input they reinforce each other, but eventually that hump of hot water in the west gets big enough that it over powers the trade winds and tries to slosh back to the east. That changes the driving forces for the winds since thermal uplift is now occurring in a different place, so the whole system reorganizes. When you shift from El Nino to La Nina you didn’t change just one thing you have a whole new system.
At least that is how I see it, coming from the perspective of a severe storm chaser. We would see this chaos play out day after day. All the atmospheric conditions were favorable for explosive thunderstorm development and nothing would happen because too many thunder cells tried to form at the same time each stealing energy from its neighbor. On other days with lower theoretical potential, you would have one cell that got just a tiny head start on its neighbors and it would grow to a monster super cell and create its own local weather environment and literally “eat” other smaller storms.
Weather is fascinating, but I suspect will never be predictable in the common sense use of the word. I fear the best we can do is establish trends and probable outcomes.
Larry

It sounds like we are just beginning to understand our climate and it’s mechanisms.
Regardless, what in the (blank) are we waiting for?
We must extract Americas oil NOW. The revenue and savings generated from home grown American energy will STIMULATE our economy. We are facing an economic crisis. Is there a [better] time to tap our own reserves? This will help buy us time to recover economically and help pay for alternative energy.
Drill here, drill now!
The prophet Al Gore and his blind sheep are only fueling the problem. This is simply more proof that extremists, sometimes unknowingly, erode the pillars of national security.
Wake up America. The planet is not anthropologically unstable. Some of the people are.

One important aspect which might help those looking for the driver of the Trade Winds is that there is a strong seasonal component to the ENSO.
About 80% of El Ninos and La Ninas start developing in the late spring and early summer. They peak around November to January.
The current La Nina is one of non-traditional 20% which do not follow this timeline although the peak could have been in January so it might fit as well.
So, it appears there is a driver related to the northern hemisphere summer which peaks and declines as the winter solstice hits.
The sun is directly overhead of the Tropic of Cancer as the trend starts, the sun then moves over the equator as the trend is accelerating the most and then the Sun is overhead of the Tropic of Capricorn as the Nino peaks and declines.
Something to think about anyway.
Pamela Gray asked about the current strength of the Trades. The Trades over the ENSO region are a little above average right now but the leading Trade Winds to the West are at their highest level in the record since 1979. This should lead to strengthening La Nina conditions if the correlation follows the previous trends.

Bob Tisdale, re the data on the currents… I’d expect that data to be available at TAO… if not then try SCRIPPS, they’ve published a few studies on them… I usually just look at the thermocline slope since it’s going to give you the same general information in different terms and is probably a bit more relevant.

Hmmmm…
“SST anomaly animation ” http://www.osdpd.noaa.gov/PSB/EPS/SST/anom_anim.html
What I find interesting is the Cooling of the North Atlantic in January and February

“In short, its the sun.”
I suspect when we get right down to it, the sun is ultimately driving this mechanism. Maybe not with direct radiation, maybe its magnetic, I don’t know. But if I were a betting man, I’d place a large amount on the sun as the primary influence on ENSO. One way or another…

We need to take all of our windmills and use them to power windmills in Africa so we can regulate our weather using the trade winds!
Insurgent:
The winds are caused by the linear speed differences caused by rotation. Winds at the equator have to travel faster to keep angular movement equal to the winds at say Montreal. But that would mean a tremendous energy force. But this does not happen. What we get instead are winds at the equator that are slower than the earths rotation. The rest of the earth rotates, and counter winds flow the other way. (Creating tornadoes if conditions are right) Every rotating body has levels of counter-rotating winds, with the winds at the center being opposite the direction of rotation.
These winds also dragon the surface and can reduce or speed angular rotational speed. This then either increases or decreases the accumulated heat, respectively, which modifies the global wind flows.

Bill Illis – Great post in explaining the trade wind links to La Nina/El Nino.
Magnetosphere modulating cosmic rays
On what causes those, one possible cause is variation in earth’s magnetosphere modulating galactic cosmic rays which affect cloud nucleation, which in turn affects the radiated vs absorbed insolation. The higher cloud density near the tropics would result in variation in ocean surface temperatures more in the tropics than in temperature regions.
Marsh (2003) shows correlation between galactic cosmic rays and El Niño–Southern Oscillation trends. Brown (2008) shows about short term correlations between 3% cloud cover variations and cosmic radiation.
The magnetosphere in turn may be modulated by solar cycles and/or internal field dynamics. Rusov et al. (2008) propose internal dynamics modulating cosmic rays.
2009 studies show cosmic rays storms have a strong impact on stratospheric temperatures. e.g. 40 deg C changes.
Following some references to these issues.
David
A brief summary of cosmoclimatology Danish National Space Center
Svensmark, Henrik, Cosmoclimatology: a new theory emerges. A & G, February 2007, Vol. 48 #1, 18-24
Marsh, Nigel, Galactic cosmic ray and El Niño–Southern Oscillation trends in International Satellite Cloud Climatology Project D2 low-cloud properties, J. Geophysical Research, V. 108, No. D6, 4195, doi:10.1029/2001JD001264, 2003
Brian H. Brown, Short-term changes in global cloud cover and in cosmic radiation, Journal of Atmospheric and Solar-Terrestrial Physics Volume 70, Issue 7, May 2008, Pages 1122-1131 See: Whiterose Online copy
“There is an association between short-term changes in low cloud cover and galactic cosmic radiation over a period of several days. This could arise if approximately 3% of the variations in cloud cover resulted from GCR.”
Rusov, V; A. Glushkov, V. Vaschenko, O. Mihalys, S. Kosenko, S. Mavrodiev, B. Vachev, Galactic Cosmic Rays – Clouds Effect and Bifurcation Model of the Earth Global Climate. Part 1. Theory, Atmospheric and Oceanic Physics, (2008) In Press arXiv:0803.2765v2
Rusov, V; A. Glushkov, V. Vaschenko, О. Mihalys, S. Kosenko, S. Mavrodiev, B. Vachev, Galactic Cosmic Rays – Clouds Effect and Bifurcation Model of the Earth Global Climate. Part 2. Comparison of Theory with Experiment. Atmospheric and Oceanic Physics, (2008) In Press arXiv:0803.2766
Cosmic rays detected deep underground reveal secrets of the upper atmosphere, A joint press release issued by the UK’s National Centre for Atmospheric Science (NCAS) and the Science and Technology Facilities Council (STFC), 21st January 2009
http://www.ncas.ac.uk/index.php?option=com_content&task=view&id=446&Itemid=249
Knudsen , Mads Faurschou & Riisager, Peter. Is there a link between Earth’s magnetic field and low-latitude precipitation? Geology 2009;37;71-74 doi:10.1130/G25238A.1
http://geology.geoscienceworld.org/cgi/content/abstract/37/1/71

For the delight of GWrs:”An ice sheet of 14,000 square kilometres has broken off..”
http://www.earthtimes.org/articles/show/256191,researchers-spot-huge-split-in-antartic-ice-shelf.html

RE RECENT ARTICLE by Dr . Vickey Pope called “SCIENTISTS MUST REIN IN MISLEADING CLIMATE CLAIMS”
By Matt Vooro
http://icecap.us/images/uploads/PDO_and_AMO_Are_the_Real_Pacemakers_for_Climate.pdf
I totally agree that scientists should refrain from making misleading climate change claims. I think the whole issue that climate change is primarily caused by manmade greenhouse gases is misleading. Natural earth/ocean climate cycles like PDO,AMO, NAO and ENSO are not even talked about by these same alarmists. IPCC climate models are strangely silent on them too. Now I wonder why? How can one trust any climate models that omit the key climate drivers.
The Pacific and Atlantic Ocean temperature oscillations as measured by the PDO, ENSO, SOI , AMO , ETC indices are prime drivers of our climate. The droughts, hot spells, rainy weather and cold spell all have their origins in the temperature oscillations of these ocean climate makers that have existed for thousand of years and explain the natural variability of the global climate. The paper here well illustrates this point.

Lame-man here…
Is there a correlation between PDO, AMO and the solar cycle
Awhiile back I did a quick look at the Spotless years, then added ~2years as it might take awhile for the oceans to show effect, then I looked at the graphs of PDO an AMO….it seems that PDO and AMO spike negative/and don’t spike positive after spotless years.
Spotless years graph
http://icecap.us/images/uploads/Sunspotless_days.JPG
pdo data
http://jisao.washington.edu/pdo/PDO.latest
pdo graph
http://jisao.washington.edu/pdo/
amo data
http://www.cdc.noaa.gov/Correlation/amon.us.long.data
AMO graph
http://upload.wikimedia.org/wikipedia/co…. resent.svg.png

Sun Heats Earth (+ve anomaly)
Sea Surface Warms
Winds Drop Off, Hurricanes Lessen
El Nino Conditions Build Up
Landmasses Warm Up
The oceans have 10,000 times the thermal capacity of the atmosphere. YET… as Bill Illis suggests to me with such poetry, the air’s kinetic energy then seems to make up for its poor thermal capacity.
THANK YOU ALL.

Leif Svalgaard (09:12:47) :
Erl Happ (08:36:52) :
When the intensity of ultraviolet light from the sun increases, temperature rises in this ozone rich air and weakens the downdraft…
In short, its the sun.
No. The amount of ozone in the upper troposphere depends on dynamical processes [waves] and transport mechanisms between controlling the downward intrusions of ozone from the stratosphere, thus driven from below. Solar activity has little [if anything] to do with this.
The absorption of ultraviolet light by O2 produces two O atoms which then combine with O2 atoms producing ozone (O3) and releasing heat energy. When ozone absorbs ultraviolet light, it splits into O2 and oxygen atoms and also releases heat energy. The net effect of the reactions above is to convert light energy into heat energy. I’m pretty sure that the ultraviolet light comes from the sun/solar activity.
Also, this reference http://www.jamstec.go.jp/frcgc/jp/press/040316/index_e.html indicates that Erl’s assumption is correct.

The account of El Nino that I read claimed that heavy fresh water rains in Indonesia contributed to El Nino spilling out into the larger Pacific.

Ray (13:46:54) :
“Talking of wind… it seems that wind turbines can create heat islands miles down. Take a look at this http://www.sciencedaily.com/videos/2005/1012-wind_farms_impacting_weather.htm and the video.”
Known to only a few, this is why the tipped-nose Pelosi mouse range has moved further north to the Frisco Bay marshes from Palm Springs in only a few short years as a result of this global warming effect.

Such a good thread. So maybe the real goodies will be found in studying this trade wind that flows East to West. If it is set up by temperature variations and rotation, anything we measure should be measured where this trade wind is. That means cloud cover, ozone blanketness (my word but it works), other trace gas blanketness, water vapor blanketness, etc, that occur in context with this trade wind. Maybe the focus should be right around the middle. Which is what I am trying to focus on since I am over a half century old. If I find out it is my Friday nights at the local tavern that is causing the bulge around the middle, I will swear up and down it is CO2. Wait…it actually could be too much CO2. Damn.

Leif Svalgaard (14:38:47) :

“The Sun’s heliosphere, not the Earth’s magnetosphere for time scales we care about. On very long time scales, e.g. millennia, the Earth’s magnetic field controls the access of cosmic rays.

I agree on the millennial influence on cosmic rays. However, would not the near term fluctuation in Sun’s heliosphere also affect the Earth’s magnetosphere and in turn modulate the incoming cosmic rays?
See: Newell, P. T., T. Sotirelis, K. Liou, C.-I. Meng, and F. J. Rich (2007), A nearly universal solar wind-magnetosphere coupling function inferred from 10 magnetospheric state variables, J. Geophys. Res., 112, A01206, doi:10.1029/2006JA012015.
Note Brown’s short 3% correlation between cosmic rays & clouds over a few days:
Brian H. Brown, Short-term changes in global cloud cover and in cosmic radiation, Journal of Atmospheric and Solar-Terrestrial Physics Volume 70, Issue 7, May 2008, Pages 1122-1131
Is there evidence that there is no correlation between the solar wind and cosmic rays that could impact the cloud cover, insolation, sea temperature and consequently the trade winds? Or might such a connection be discoverable?

Leif Svalgaard
Could you please briefly explain what Newell et al. (2007) found and how it does/does not affect the impact of cosmic rays on low level clouds.
See: Newell, P. T., T. Sotirelis, K. Liou, C.-I. Meng, and F. J. Rich (2007), A nearly universal solar wind-magnetosphere coupling function inferred from 10 magnetospheric state variables, J. Geophys. Res., 112, A01206, doi:10.1029/2006JA012015.
Apparently I misunderstand the effects and/or terms.

Let’s all use the right words for the same meaning.
Andre (22:47:47) wrote “Air moves from the tropics toward the equator to replace the hot air ascending over the latter.” By equator is meant the ITCZ (see below).
And crosspatch (02:20:13) wrote “Heated air rises above the tropics (again, ITCZ) and flows toward the higher latitudes (should be altitude), where it cools, sinks, and flows back toward the tropics (over the Tropics toward the ITCZ) in an easterly (east to west) (actually, NE to SW) surface pattern known as the trade winds. This constant, overturning flow in the tropics (troposphere) is called the Hadley circulation.
I think someone else had a similar comment also. Word usage and perhaps concepts seem to be getting a bit fuzzy. It is important to keep the regions and what is going on clear.
Usually, when speaking of these things we have polar latitudes, high latitudes, mid-latitudes, sub-tropical, tropical, and equatorial. Because the vertical sun travels back and forth across the Equatorial regions – mostly ocean – the air becomes warm and humid, and becomes buoyant. It will tend to rise. Clouds form (heat is released) and shadow. ItThe rising air is replaced by near-surface air flowing across the tropical latitudes, or Tropics. In the northern hemisphere these near surface winds appear to flow from the northeast, and because they were important in the age of sailing ships (think Columbus), they were called the Northeast Trades.
The SE Trades and the NE Trades usually meet, or almost meet, in the Equatorial area and thus the name Intertropical Convergence Zone (ITCZ). [One time when they did not meet has given us Coleridge’s The Rhyme of the Ancient Mariner.] The Trades feed into the Walker Circulation. In general, though, having risen to some height near the top of the troposphere (the tropopause) the air heads pole ward. The rotational effect (CORIOLIS force) gives this flow – high over the Tropics and the Trades – an eastward (right-hand) bias in the northern hemisphere. This high altitude air has lost its moisture and continues to loose heat (radiative cooling), becoming cold. Over the Subtropical areas it sinks toward the surface. The descent causes compressional warming (adiabatic descent) and the air nears the surface as a relatively warm dry air mass. The near-ocean surface air below it can be a few degrees cooler and a temperature inversion – almost no wind or clouds but hazy – frequently occurs. These areas are Sub-Tropical High Pressure (STHP) and provide the air that feeds the Trades and the air going north that feeds the Westerlies. Over land, winds that are part of the Hadley Cell still operate. In the Sahara they call this “trade wind” the Harmattan.
Not related to the above but: The western Pacific Ocean is topographically restricted (barrier like) while the Atlantic is not and the Atlantic, in the region of concern has the Amazon’s massive fresh water flow (over denser salt water) to add to the difference.

Sir Anthony of the Watt:
A request please from this squire of your realm (Robt wonders if he is buttered up enough yet….) On a separate (but closely related) thread please address how much syrface and oceanic topography is actually included in the so-highly funded GCM that the world’s economies are now chained to.
Are ocean area represented – if so, how closely do their surface areas (their
finite element cubes) match the real world along the Pcific and Atlantic shores.
Do the GCM’s actually model (or predict) or even “notice” ENSO and PDO cycles? If not, why not.
Once a GCM has cycled for several hundred “years” (and do they model the “solar year” with it’s changing radiation and incidences, or only the “average” entire year ?) do any of them begin to create oscillations similar to ENSO’s?
Do GCM’s “create” cold fronts and the arctic air flows when they run, or are they “static” heat exchange models only (radiation received and radiation released are obviously their “drivers” … But what happens after the air masses have been “driven” for the equal of one or two “years” – do we see flows in the tropics, mid-latitudes, and polar latitudes than resembles earth’s circulation? Or do the final patterns more closely resemble the moon’s weather? 8<)
I have run, edited, definied, critiqued, created, and used the results from nuclear (neutron flux) 3D finite element models, stress-strain mechanical design models, heat flow finite elements, machining FEM’s, fluid flow 3d models, and even concrete and molded metal models. How large are the GCM “grids (boxes) and what “information” is “shared” through each element face as the simulation progresses?
How are GCM “boxes” divided vertically through the atmosphere? How do they account for mountains and large permanent influences like deserts, huge areas of grasslands (central US, central Russia, India, France, etc) compared to mixed regions like the Med, Great Lakes, and CA and smaller pennisulas or desert areas?
If the “boxes” are so large that every land area is considered equal – how are coastal regions and ice-covered areas modelled as they change over the year?
REPLY: Thank you, but I’m not an encylopedia for hire, perhaps readers can help with questions. – Anthony

The people who are arguing about oscillations that are totally within the Earth’s atmospheric/ocean system must realize that their debate is
ultimately pointless if the factors which control the long term changes
in the trade winds are externally driven.
I beleive that the following two graphs clearly show that changes in the PDO are driven externally by an as yet unknown process that is synchronised with the solar motion about the Solar Systems centre of mass. {note: I am not saying that the solar motion is causing the process, nor am I claimng to lnow
what this process is.]
http://f1.grp.yahoofs.com/v1/oC2dST9xJv9nbcZK4Og69pNMoPPG484WXOoWxYpaf-Q8d5BSUmpD6bHsnFVyTKnI-XmwMW0P40uyJEIPd0aw3Q/PDO_ROT.JPG
http://f1.grp.yahoofs.com/v1/oC2dSYSsAkxnbcZKvtKWaDBd-ktW0ZD8IXAIa9u5WwfBsttzY3QtPVNy3OCAw28wK2uTAjNvsccuZ-86VG8NyQ/Solar_rot.JPG
If you cannot see these graphs please let me know.
And I believe that the following graph shows that it is the PDO that reinforces the ENSO and not the other way around. This third graph clearly shows that
whenver the PDO is positive, the level of intensity of El Ninos get strong and strong, and whenever the PDO is negative, the intensity of the El Ninos gets weaker and weaker. Logic tells you that it the phase of the PDO (which seems to flip from a postive to a negative state] that is influencing the intensity
level of of the El Nino phenomenon.
http://f1.grp.yahoofs.com/v1/oC2dSbCyqOVnbcZKTWnhnZ-WlllYcH_NW8R6iolAo0Vu2EgQJCPL2munw3KTVhEB9KAX2_YykoYk_okI5ZfEaw/ENSO_PDO_COMP.JPG
Could someone one please explain why the PDO climate system seems to be
synchronized with the motion of the Sun about the centre of mass of the solar system?
Dismssing this data out-of-hand with trite arguments about how you don’t like what it implies will not hold water in the long run.

Robert A Cook PE: I can try to answer part of your questions or at least provide you with links that can. The models used for IPCC projections do NOT model ENSO correctly, if they model it at all. This was confirmed by Kevin Trenberth a few years ago in a post at the Nature blog:
http://blogs.nature.com/climatefeedback/2007/06/predictions_of_climate.html
He wrote, “None of the models used by IPCC are initialized to the observed state and none of the climate states in the models correspond even remotely to the current observed climate. In particular, the state of the oceans, sea ice, and soil moisture has no relationship to the observed state at any recent time in any of the IPCC models. There is neither an El Niño sequence nor any Pacific Decadal Oscillation that replicates the recent past; yet these are critical modes of variability that affect Pacific rim countries and beyond.”
There are coupled GCMs that do attempt to model ENSO, with mixed results. Refer to:
“The El Niño Southern Oscillation response in the BMRC Coupled GCM”
http://www.bom.gov.au/bmrc/pubs/researchreports/RR91.pdf
And to:
“ENSO dynamics in current climate models: an investigation using nonlinear dimensionality reduction”
http://www.nonlin-processes-geophys.net/15/339/2008/npg-15-339-2008.pdf
And to:
http://www-pcmdi.llnl.gov/wgne2007/presentations/WGNE-Workshop/Manganello_WGNE.pdf
Eric Guilyardi has a number of papers here about CGCMs and their problems (and advences) with modeling ENSO here:
http://www.met.rdg.ac.uk/~ericg/publications.html
There are many more critiques (refer to references in the above papers) available through Google. I hope that helps.
Regards

The trade winds are driven by the coriolis forces that are generated by the vertical movement of the atmosphere in the tropics. The strength of the coriolis forces and hence the trade winds is directly related to the strength of the vertical movement of the atmosphere. This is inescapable. Hence the strength of the vertical atmospheric movement determines the strength of the trades.
The strength of the vertical movement is controlled by the same factors that control atmospheric convection elsewhere. Lapse rates, humidity and heat input are important.
Perhaps a specialist in atmospheric convection could identify the cyclic factors that are causing variations in the strength of convection. However I bet the sun has a lot to do with it.

Ninderthana: Your links don’t work.
Regardless, you wrote, “And I believe that the following graph shows that it is the PDO that reinforces the ENSO and not the other way around. This third graph clearly shows that whenver the PDO is positive, the level of intensity of El Ninos get strong and strong, and whenever the PDO is negative, the intensity of the El Ninos gets weaker and weaker. Logic tells you that it the phase of the PDO (which seems to flip from a postive to a negative state] that is influencing the intensity level of of the El Nino phenomenon.”
Actually, it’s ENSO that drives the PDO.
First, the process used to calculate the PDO (and it is a process) was first developed to extract the ENSO signal from North Pacific SST anomalies. Refer to Zhang et al (1996) “ENSO-like Interdecadal Variability: 1900–93”.
http://www.atmos.washington.edu/~david/zwb1997.pdf
Second, if you were to plot the monthly NINO3.4 SST anomalies and the PDO in a comparative graph, you’d discover that there is little difference between the two.
http://i25.tinypic.com/14dj904.jpg
Refer to:
http://bobtisdale.blogspot.com/2008/06/chicken-or-egg-pdo-or-enso.html
Third, in “ENSO-Forced Variability of the Pacific Decadal Oscillation”, Newman et al state in the conclusions, “The PDO is dependent upon ENSO on all timescales.” Refer to:
http://www.cdc.noaa.gov/people/gilbert.p.compo/Newmanetal2003.pdf
Refer also to my post about “The Common Misunderstandings About The PDO”:
http://bobtisdale.blogspot.com/2008/06/common-misunderstanding-about-pdo.html
Regards

erlhapp (07:15:08) :
Thank you, crystal clear fundamentals with insightful highlights. Just what the majority asks for at WUWT.

Alan Millar (07:45:55) :
What this also shows is that this is yet another reason to enforce sustainable management of these tropical forests.

Tallbloke: ” Knock it off Chris. We are lucky to have Leif here to be so generous with his time, patience and expert knowledge. Whatever his personal belief’s are, he is always honest and informative. I’ve taken a few jibes from him in the past, but I still respect his integrity as a scientist. I think he just wants to see science done rigorously.”
I realize that Leif has established a solid reputation at WUWT and that it is considered heresy to doubt his motives. And indeed I may do him a great injustice to doubt his motives. My remarks stem from a sense of frustration brought about by my observation that Leif is always quick to point out (perceived) errors by others but never makes the slightest attempt to come up with any constructive suggestion as to why climate is going through colder and warmer phases. Any mechanism that could possibly explain a causal link between the sun and (for example) the LIA will immediately be quashed or ridiculed by Leif.

Leif,
“Without GHCs the Earth would be too cold to live on”
How is oxygen and nitrogen heated then? I find it highly unlikely that a trace gas can have such significant impacts on heating the other 99.9% of our atmosphere, considering that CO2 only absorbs 3 narrow bands of IR.
How much warming [on earth] do you think is attributed to 0.0385% CO2, considering all known and unknown variables?

Every skeptic should be required to say this quote before opening their mouth to opine about global climate: “You do not combat the bad science of AGW with even worse science.” Leif Svalgaard 05:24:43

Damn. One glass of red wine and I type like this: I kown, I khown, I cneeed to gett out t more otften.

erl. Buddy. Have a Coors. You can talk mechanism all you want, but if ozone variations (which have been measured) don’t coincide with temperature changes (which have been measured), ya got to move on! I got myself all in a lather over the ozone hole over Oregon (hey, give me some slack, being a redhead and all, ozone protects me from the Sun!) this past Summer. It was interesting to watch the ozone thin during the day and then thicken up at night. The thinning spread over a larger and larger span of the western states.
But here’s the thing. The thing that kept pinging on my head (not to mention Leif questioning my questions about ozone) is that it did not feel any hotter or colder than usual. And by usual I mean the usual variations that occur with a cold or warm Pacific. I eventually led myself back to weather. Yes weather. Not climate. I re-introduced myself to the old standby definition of climate and returned to weather pattern variation. I think I am on the right track. It ain’t glamorous and sounds a bit “Farmers Almanac-ish”. But it seemed to work for old time farmers. “Earl, what’s the weather like?” “Let me take a look Billy. Looks like its gonna rain.” So I think it will work for me.

Ozone is not well mixed or evenly spread. The atmosphere and its winds move it here and there. It is thick in one place, then thin in that same place the next day or week (and I am only speaking relatively here, the changes are actually quite small). If a lack of ozone causes temperature changes it is as hard to nail down as jello to a tree. Besides, how much change do you expect? The change in temperature, under the current conditions, as a result of ozone affects are as small as CO2, compared to the cold wind that blows up your skirt from an Arctic blast. I think you will find a much greater correlation between long term temperature changes when El Ninos dominate or La Ninas dominate. And it looks like those are partly due to a Pacific Oscillation that may be due to some kind of conveyor belt and/or equatorial trade wind. And the trade winds are due to a dance between the Earth’s rotation and temperature differentials. So if the trade wind is strong or week based on a temperature difference along its sides, you would need to measure ozone along this band, and then only under the conditions you suppose. When the Sun is blank of sunspots.
Here ya go:
http://exp-studies.tor.ec.gc.ca/e/ozone/Curr_allmap_g.htm

Bob, I put the 120 to 175 datasets together weighted for the size covered by each.
(There is 5 degrees coverage missing but you have to work with what is available. I didn’t think it was important enough to get into in the short post space that is available.)
There is a lot more technical science and theory that could have been discussed in the post like the Walker-Circulation model (from 1923), the Madden-Julian oscillation (which in my mind shows how the ENSO helps drive the PDO and you can see this in the animations of the ENSO region), how the thermocline reacts during ENSO events, Kelvin Waves etc.
The data says there is no reason to make this very complicated and the data doesn’t take you to a theory called the Walker circulation – it takes you to a very simple and a very explanatory “the Trade Winds”. And they are updated daily.
Given the shortage of space and the fact there was no reason to over-complicate this, I didn’t get into everything.
http://en.wikipedia.org/wiki/Walker_circulation
http://en.wikipedia.org/wiki/Madden_Julian_Oscillation

Leif,
“The GHGs sends some of the long-wave radiation back to the surface, heating it up some more, adding to the heating. Why is everybody so hung up on CO2. H2O is much more important. Even O3 makes a contribution. Basically, you need a [at least] tri-atomic molecules to get enough IR absorption. ”
If oxygen and nitrogen absorb heat, then clearly they radiate heat. What I conclude is that our air is heated without the help of GHG’s or without a molecule requiring 3 atoms. I am not saying that GHG’s do not add to the heating, but I believe it is impossible for CO2 to have a “significant” impact on heating the remaining 99.9% of our atmosphere.
I am hung up on CO2 because our fearful leaders are about to tax/offset CO2, yet we have no idea how much warming is atrributed to it. This is known as taxation without representation, which is one of the reasons America declared it’s independence from England. Taxation without representation… it lead to a Revolution.
We will soon have the taxation. Where is the representation? The greenies/neo-marxists are treading on thin ice as far as I am concerned. Hopefully, with time, they will drown this nonsense before it causes more economic damage.
With that, we must extract American oil NOW. The revenue and savings generated from home-grown American energy will STIMULATE our economy. We are facing an economic crisis. Is there a [better] time to tap our own reserves? This will help buy us time to recover economically and help pay for alternative energy. Drill here, drill now!
Al Gore and his blind sheep are only fueling the problem. This is simply more proof that extremists, sometimes unknowingly, erode the pillars of national security.
I believe that the planet is not anthropologically unstable. Some of the people are.

The GHGs sends some of the long-wave radiation back to the surface, heating it up some more, adding to the heating.
“If oxygen and nitrogen absorb heat, then clearly they radiate heat. What I conclude is that our air is heated without the help of GHG’s or without a molecule requiring 3 atoms. I am not saying that GHG’s do not add to the heating, but I believe it is impossible for CO2 to have a “significant” impact on heating the remaining 99.9% of our atmosphere.”
Rich, you were on the right track. All real materials have differing rates of energy absorption and emission given as a fraction of Einstein’s ideal black body.
Green leaves emit 94% as readily, snow 84%, pure water 58%. CO2 emits/absorbs at 0.09% at sea level and 20 degrees C. Yes, no typo.
Energy flow is therefore one way only, up and out. Of the radiation GHGs absorb they give up the energy acquired via conduction to their neighboring molecules in collisions.
And this is also the way air transfers energy to the surface only by conduction, when it is warmer than the surface. On a water planet, most heat transferred from the surface is removed via evaporation, the heated air rising via convection.

Leif & Gary,
Thanks for your thoughts. Sorry for getting political.
I agree with H20 as a GHG, but if it were not for Earth absorbing the sun, warming the oxygen and nitrogen in our atmosphere, then the Earth would be a “very cold place”. Warming stems from the Earths “initial” absorption, does it not? The water vapor in our atmosphere is feedback from this initial absorption, is it not? The air around black body surfaces is warmer, which has nothing to do with how many triatomic molecules are floating nearby, right?
Can you approximate how much H20 in ppm makes up our atmosphere?
Thank you.

I read regularly, and comment sometimes, and I wanted to ask Leif a question.
Does the sun swell and contract with internal temperature fluctuation? Is there any way to measure that, and would it affect our temperature any?

Erl on Feb 18, 15:03:07 “Sudden stratospheric warmings in the Arctic depend upon the transport of ozone rich air from above the Sea of Japan. That depends upon activity in the Siberian High pressure cell and the phenomenon described as a ‘Planetary Wave’.
Yes, a great deal depends upon transport phenomena that bring s ozone to a place where it intercepts ultraviolet light. Then we see the temperature jump by 50°C in the middle to upper stratosphere in the polar regions. We also see the temperature fall in the stratosphere over the Equator at exactly the same time. That is a very interesting phenomenon. Perhaps you could tell us what might be responsible for sudden ‘coolings’ in the equatorial stratosphere.”
Hi Erl, all, Thanks for very interesting thread. Looking at this fascinating NASA’s Earth Observatory’s animation of the recent Arctic SSW, it peaks some time before the vortex snapped in two. Still it’s more due to dynamics than ozone? Are equatorial events linked to it, this time? And were we perhaps relieved significantly of some polar surplus heat? At least we enjoy some cold from it now 🙂 Best regards, Soren Floderus, Swedish/Danish physical geographer, Copenhagen

Ninderthana,
Thank you for the interesting IanWilsonForum2008.pdf. Finally someone on the right track, just two things missing. The Earth’s LOD is also influenced by the gravity of the Moon, Jupiter and Venus. And the mechanism like I have explained earlier. When the revolution speed changes (caused by external gravity) the rotation speed also changes. In the case of the Sun it modulates the activity. In the case of the Earth, because the landmasses are connected to the inner parts while the oceans and the atmosphere are not, the ocean and atmosphere speed up relative to the landmasses altering the currents.

Regarding the PDO and the ENSO,
The two indices often move together. Sometimes it seems that the ENSO is leading the PDO and other times it seems that the PDO is leading.
One important point about the PDO is that charts of the PDO index you might have seen on the internet have been highly smoothed out. The actual monthly PDO index values are extremely variable and, hence, it is hard to use the PDO in models or temp reconstructions.
I think they are really part of the same system and the ENSO’s impact is easier to model and understand than the PDO so I will continue using it rather than the PDO.
http://en.wikipedia.org/wiki/Pacific_Decadal_Oscillation
Another VERY important point about the ENSO, (and maybe I should have put this into the post) is that the ENSO mainly affects the Tropics and the Northern Hemisphere only.
The ENSO is only lightly correlated with Southern Hemisphere temperatures(you might not have heard that one before).
The ENSO has 10 times bigger impact on the Northern Hemisphere than the Southern Hemisphere and 20 times the impact in the Tropics than in the Southern Hemisphere.
I guess that makes sense since the ENSO is a Tropics phenomenon and the ENSO / PDO system are mainly a northern Pacific phenomenon.
Another little piece of the puzzle.

Ed: “The temperature variability in the Arctic stratosphere in the winter months is remarkable. ”
Indeed, and forgive me if I just don’t know, but to me from the animation it seems like just warmer tropospheric air splashing up into the stratosphere due to vortex dynamics, maybe as the west and east edges almost meet and start to collide? – or would that all be density- or heat-wise impossible?

Gary, thanks for the info.
Tallbloke,
“I estimate that would be at 11,000-20,000ppm”
Hmmm… but we don’t have enough fossil fuel reserves to come close to that amount of atmospheric CO2. I don’t have time to look at Bill Illis’ link right now, but I will. Thanks for your insight.