Guest post by Erl Happ
The Southern Oscillation Index is a reference point for the strength of the Trade winds. It represents the difference in atmospheric pressure between Tahiti and Darwin. In figure 1 the SOI is the red line with its values on the right axis. A negative SOI reflects slack trade winds and a warming ocean. A positive index relates to a cooling globe. Note that the right axis in figure 1 is inverted.
How is it that change in surface atmospheric pressure is so closely associated with a change in the temperature of the tropical ocean? This is the major unsolved riddle in climate science. If temperature is so obviously associated with pressure on an inter-annual basis why not in the long-term? In this article I show that pressure and temperature are intimately related on all time scales. In other words, ENSO is not an ‘internal oscillation of the climate system‘ that can be considered to be climate neutral. ENSO is climate change in action. You can’t rule it out. You must rule it in. Once you do so, the IPCC assertion that the recent increase in surface temperature is more than likely due to the works of man is not just ‘in doubt’, it is insupportable.
If the IPPC can’t explain ENSO it can not explain climate change. It is not in a position to predict surface temperature. Its efforts to quantify the rise in temperature must be seen to be nothing more than wild imaginings. Its prescriptions for ‘saving the planet’ must be viewed as ridiculous.
Surface pressure data: http://www.longpaddock.qld.gov.au/seasonalclimateoutlook/southernoscillationindex/soidatafiles/index.php. Monthly temperature data: http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl
Temperature change is linked to change in surface atmospheric pressure
Figure 1 Left axis Temperature in °C. Right axis three month moving average of the monthly southern Oscillation Index
The Southern Oscillation Index leads surface temperature on the upswing and also on the downswing. Some factor associated with change in surface pressure is plainly responsible for temperature change.
How and why does atmospheric pressure change?
The evolution of surface pressure throughout the globe depends upon the activity of the coupled circulation of the stratosphere and the troposphere in Antarctica and in the Arctic. These circulations have become more aggressive over time resulting in a loss of atmospheric mass in high latitudes and gain at low latitudes. The gain at low latitudes reflects the seasonal pattern of increased intensity in the respective polar circulations. The stratosphere and the troposphere couple most intensely in February in the Arctic and in June through to September in the Antarctic. The pattern of enhanced activity at particular times of the year is reflected in the timing of the increase in sea surface pressure in equatorial latitudes, as seen in figure 2.
Figure 2 Gain in average monthly sea level pressure between the decade 1948-1957 and the decade 2001-2010. hPa
The coupled circulation in the southern hemisphere produces a deep zone of low pressure on the margins of Antarctica that encircles the entire globe as is clearly evident in figures 3 and 4. In previous posts I have documented the change in high latitude pressure since 1948 and the associated change in wind strength, sea surface temperature and by inference, since the atmosphere is warmed by the descent of ozone into the troposphere, a change in cloud cover.
Figure 3 Mean sea level pressure January
The pressure deficit on margins of Antarctica is deepest in July (winter).
Figure 4 Mean sea level pressure July
It is of interest therefore to look at the evolution of the pressure relationship between Tahiti and Darwin (that is the essence of the SOI) over time.
Bear in mind that as atmospheric mass moves from high latitudes to the equator atmospheric pressure increases at Darwin more than it does at Tahiti and the trade winds slacken. The increase in pressure at Darwin is well correlated with the increase in atmospheric pressure in equatorial latitudes globally. The plunge is atmospheric pressure at high latitudes that enables the increase in pressure at the equator is associated with cloud loss and increased sea surface temperature in mid and low latitudes. The most abbreviated explanation of mechanism behind the loss of cloud can be found here: http://wattsupwiththat.com/2011/08/20/the-character-of-climate-change-part-3/
Figure 5 Thirty day moving average of the difference in daily sea level pressure between Tahiti and Darwin hPa.
The excess of pressure in Tahiti with respect to Darwin over the period 1999-2011 is shown in figure 5. The differential plainly evolves over time and an indication of the direction of change is given by the fitted polynomial curve.
Secondly, we can see that the pressure differential exhibits a pattern of seasonal variation. In general the pressure differential is high at the turn of the year and low in mid year.
The pattern of the average daily differential for the entire period for which daily data is available (1992 -2011) is shown in figure 6.
Figure 6 Average daily sea level pressure differential between Tahiti and Darwin over period 1992-2011. hPa
We observe that the pressure differential between Tahiti and Darwin:
• Reflects strong variability even when averaged over a period of twenty years.
• Is greatest between late December and the end of February (strong Trade winds)
• Is least between April and September (weak Trade winds).
• Shows a pattern of enhancement in February- March and also in September- October that plainly relates to the pattern of pressure increase in near equatorial latitudes evident in figure 2. The shift in the atmosphere away from Antarctica tends to enhance the pressure differential driving the trade winds all year, but in particular in September and October. So far as the Arctic is concerned the pressure loss is centered on February and March.
Why do the trades tend to fail in mid year?
Figure 7 Sea level pressure hPa. Seasonal pattern in Tahiti and Darwin.
The erosion of the pressure differential in southern winter relates to the establishment of a high pressure zone over the Australian continent. Compare figures 3 and 4 noting the difference in atmospheric pressure over Australia in summer and winter.
Change in the pressure differential (and the trade winds) over time.
In figures 8-11 the evolution of the pressure differential between 1997 and 2000 is compared with its evolution between the years 2009-2011.
Figure 8 Daily pressure differential. Tahiti less Darwin. hPa
The first and largest El Nino of solar cycle 23 began in early 1997. The first El Nino in Cycle 24 started in late 2009. The pattern of the differential is shown in figure 8. Plainly, the reduction in the pressure differential was more extreme in 1997 than in 2009.
Figure 9 Daily pressure differential. Tahiti less Darwin. hPa
The reduced differential persisted till March in 2010 and May in 1998. The last half of the year saw a strong recovery.
Figure 10 Daily pressure differential. Tahiti less Darwin. hPa
In 1999 and 2011 we see a strong pressure differential (La Nina) in the early part of the year, and in the case of 1999 this enhanced differential persisted through to the end of the year. The differential in early 2011 was much stronger than it had been in 1999.
It is noticeable that week to week variability is enhanced in 2011. I suggest that this relates to increased plasma density in an atmosphere due to reduced ionizing short wave radiation in solar cycle 24 by comparison with 23. Under these circumstances El Nino and La Nina produce a relatively ‘wild ride’.
We note the extension of La Nina into a second year.
Figure 11 Daily pressure differential. Tahiti less Darwin. hPa
2000 was a La Nina year coinciding with solar maximum. A coincidence of La Nina with solar maximum is more usual than not. On that basis one expects the current La Nina to continue into 2012. However, given the relative deficiency in short wave ionizing radiation in cycle 24 with respect to cycle 23 this time around might be different. The likely lack of a well-defined peak in cycle 24 will make a difference. If the cycle goes in fits and starts, so to will the ENSO experience.
Is the climate swinging towards El Nino as it warms?
It is a favorite meme of those who suggest that the globe is warming ‘due to change in trace gas composition’ that the climate is likely to progress towards a more of less permanent El Nino existence. Does recent history support this assetion? Is a warming globe associated with increased incidence of El Nino?
Figure 12 Average daily pressure differential Tahiti less Darwin hPa
In the six year period 1992-1997 the average daily pressure differential reveals an El Nino bias in relation to average for the entire period 1992-2011. In this period the globe warmed, but the degree of warming was subdued by the eruption of Pinatub0 in 1991.
Figure 12 Average daily pressure differential Tahiti less Darwin hPa
A cooling bias is evident over the last seven years from 2005 through to 2011.
Figure 13 Average daily pressure differential. Tahiti less Darwin. hPa
Plainly there has been a progression away from an El Nino towards a La Nina state over the twenty years since 1992. In the period to 1998 the globe plainly warmed. In the period since 1998 warming seems to have ceased. There have been a suggestion that some heat that ‘should be there’ has gone missing. Can this be read as an admission that warming has either slowed down or has actually ceased?
Conclusion:
ENSO is not climate neutral. ENSO is the reality of climate change in action. The progression towards cooling that is evident in the increasing pressure differential between Tahiti and Darwin shows no sign of abating. The ENSO state changes not only on an inter-annual time scale but on very much longer time scales. ENSO is plainly not ‘climate neutral’.
If we look back at figure 1 we will see that the Southern Oscillation Index leads the change in tropical sea surface temperature on the upswing and the downswing. The SOI is more positive (cooling) in 2011 than it has been at any time over the last sixty years.
Until the IPPC can properly account for ENSO cycles they can not attribute climate change to ‘change in trace gas composition due to the works of man’. We see an excellent correlation between surface pressure and surface temperature and no correlation at all between trace gas concentration and surface temperature.
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“How is it that change in surface atmospheric pressure is so closely associated with a change in the temperature of the tropical ocean? This is the major unsolved riddle in climate science.”
Yes, we have yet to discover the Gas Law. Until then, all is shrouded in mystery.
As I read WUWT pieces like this I find myself wondering what went wrong with science.
Climate science has delivered the most inflated significance in human history. The miniscule human generated portion of trace atmospheric CO2 is only what it is. Essentially meaningless.
Yet modern day science, with all it’s advantages and 1000s of colaborative participants, has been unable to avoid a fabrication of biblical proportions and a campaign using every modern day manipulation to impose it as truth and discovery.
With it’s many layers of deceit throughout academia and governments several science generations are being tainted beyond recognition.
With so many particpants entrenched in instituions and bureaucracies I can’t even imagine a full recovery as possible. In fact it is quite likely to get worse despite the tremendous work like Erl’s, WUWT et al.
The many participants being so well insulated from the truth and consequences is a scary reality that may spawn even worse depratures from honest science.
I like to presume science is in recovery.
But is that true? Or is it in fact getting worse?
How do we know?
Can we know?
Philip Bradley says: September 23, 2011 at 2:57 am
Sorry, I should have replied to this earlier.
The Earth definitely has its maximum heat gain in January. The SH oceans gain more heat at this time than the NH land loses heat. The reverse is true in July and the Earth has its maximum heat loss at this time.
Clouds may play a role in the atmospheric temperature changes between July and January, but that role is secondary to the land versus ocean effect.
Let’s distinguish between energy gain and the temperature status of air near the surface. It’s a fact of life that global air temperature falls to a minimum in January. It’s also plain that the northern hemisphere ejects rather than absorbs energy because it has most of the land and that energy heats the atmosphere reducing cloud cover.
I don’t think anyone has quantified the energy gain by the Earth system in January versus July. You might be right but then again you may be wrong because the southern hemisphere loses a lot of cloud in the subtropics in winter.
The lower global near surface air temperature in January relates to cloud cover increase of about 3%, perhaps the ability of the southern ocean to absorb energy without returning much at all to the atmosphere and perhaps also the rather severe chilling that occurs in a very cloudy northern hemisphere where there is so much land. The land does not store energy like the sea.
Actually, if you want to see the effects of the endpoints you could graph 14 month periods (or more – 18-24 may be better), repeating the last two months(or however many required to even the period) on the first two months of the next graph, say graph from Nov – Feb, so the first plot would be Nov91-Feb93, the next would be Nov92-Feb94, etc, It won’t change the results, but the curve fits might be more obvious if there is a sinusoidal overlay.
I still think the feedbacks and the reaction time constants are going to be the key to understanding our continuously changing global climate. I haven’t read anything that seems to be close to a solution for those, and the climate models won’t shine any light on them at all, because they don’t even try to model them (they’d probably get it wrong anyway so maybe just as well).
“How is it that change in surface atmospheric pressure is so closely associated with a change in the temperature of the tropical ocean? This is the major unsolved riddle in climate science.”
lHow astounding this statement is to me. I would have to say that these “climate scientists” must never have taken a comprehensive course in chemistry in high school, let alone in college.
Lower atmospheric pressure enhances evaporation of surface water, and the specific heat of vaporization (the change in state from liquid to vapor) of H2O is high . . . in older terms, 539 calories per gram of H2O evaporated, or 539 BTUs per pound, and that amount of heat is transfered from surface waters to the H20 molecules when those H2O molecules become entrained in the atmosphere. Of course, higher velocity surface winds also greatly enhance this evaporative process.
Perhaps a high school course in chemistry followed by a college course in chemistry, say a couple of semesters of 5 unit courses, 3 lectures and 2 labs per week, would help signficantly.
RR Kampen says: September 23, 2011 at 8:21 am
Gas laws we have aplenty and they are not especially relevant. What we are talking about here is shifts in atmospheric mass from one place to the other and the persistence of the new arrangement over long periods of time like sixty years. Now that can occur when ozone descends into the troposphere resulting in localized heating and a loss in the weight of the atmospheric column in that place. To that extent the gas law is relevant.
Steve Oregon says: September 23, 2011 at 8:26 am
I like to presume science is in recovery.
But is that true? Or is it in fact getting worse?
How do we know?
Can we know?
In my experience over several years a practitioner in academia either likes to do something entirely different on his evenings and weekends (e.g. fishing) or else he has written his lecture notes a long time ago and doesn’t like the idea of having to revise them. Add this: He may depend for his continued employment on maintaining the lie and doesn’t fancy his chances of getting a job if the rationale for his employment were to suddenly disappear.
Please bear with a layman’s questions.
My take-away from this article is that:
1. ENSO is a major factor in global climate change.
2. Current “Team” models assume ENSO is neutral factor in global climate change.
Obvious conclusions may be drawn from that. Am I missing anything?
Here is a nice tutorial for the average person to help in understanding atmospheric circulation. The beginning is general background so read it all the way to the end.
http://rst.gsfc.nasa.gov/Sect14/Sect14_1c.html
Owen says: September 23, 2011 at 8:49 am
Actually, if you want to see the effects of the endpoints you could graph 14 month periods (or more – 18-24 may be better),
Let’s not be too pedantic here. My point is that the pressure differential is greater at the end of the year than in the middle. I explain why that is so in terms of the establishment of a high pressure cell over Australia in southern winter. It has long been observed that most of the variability in ENSO is centered on the end of the year rather than the middle. It just so happens that global cloud cover is maximal about the end of the year. If you are looking to discover what changes pressure (shifts atmospheric mass) and cloud cover about the end of the year look to the Arctic Oscillation also known as the Northern Annular Mode.
All these points relate to understanding the phenomenon. The type of curve that is fitted to summarize the progression of the pressure differential is not a big thing to worry about and will not enhance our understanding of the phenomena very much at all. The reason for the curve is to assist the eye to discover the shape and extent of the variability and so focus the mind on why things might be as they appear to be.
pittzer says: September 23, 2011 at 9:00 am
Got it in one. But I would like you to be able to explain to your mates at work how ENSO is forced in one direction or the other, becoming an agent for warming or an agent for cooling. You won’t be able to do this from this post alone. There are other posts and more to come.If you are impatient: http://www.happs.com.au/images/stories/PDFarticles/TheCommonSenseOfClimateChange.pdf
erl happ says:
September 23, 2011 at 8:12 am
…………..
Sorry James, not going to buy it.
===============================================
Erl, I’m not taking a position, but I’m simply stating we may benefit from exploring the thought. From your post, it is almost impossible not to consider the IGL or some of its variants(Boyles….etc). However, if it isn’t your desire to veer in that direction, so be it, it’s your post.
I’ll simply leave you with this, Venus has a remarkably similar temps to earth where the bars are the same. Energy, heat transfer and work……. mysterious things, they are.
Erl, thanks for the response,
James
Even more fundamental than the ideal gas law in this case is the simple definition of
P = F/A
For the atmosphere as a whole, the force = (mass of atmosphere) x (9.8 m/s^2) and area = (Surface area of the earth).
To the extent that the surface area and mass of the atmosphere are constant, the global average pressure will stay the same, independent of the temperature.
Or put another way,
P = nRT/V
If you raise the temperature of the atmosphere, the atmosphere will expand. The increase in T & V will offset, leaving P essentially unchanged.
(Net changes in humidity will cause mass to change, which would change the global pressure. A net upward/downward acceleration of the atmosphere would also result in a net change in pressure (but that could not last long!). There must be a few other small, temporary affects that could come into play. And of course, mass movement of air due to uneven heating of the surface can have localized affects on pressure, which would drive winds and weather.)
OH. MY. GAWD!!! It’s worse than we thought!!!
It’s man-made air pressure change. All those CO2s are heavier than regular air. Since we keep pumping them into the atmosphere, the atmosphere is getting heavier. We’ll soon be CRUSHED under the weight of it all…. AAAAAAAAAAAAAAIIIIIIIIEEEE!!! Where’s AlGore? Where’s the IPCC? Where’s the nearest steel building that will hold all that heavy air up off of me?!? There’s the connection that Al missed: as the atmosphere is compressed it heats up, so we’re not just going to broil ourselves and the poor polar bears off the face of the planet, we’re going to be smooshed… SMOOSHED… I tell you, into hot steaming piles of people and polar bear pudding! (/sarc)
Well, I can guarantee that if this takes off in the warmist camp there will definitely be hot steaming piles, but not of people or bears… (as opposed to now?) 😉
Tom in Florida says: September 23, 2011 at 9:06 am
Great stuff Tom. Its the sort of stuff I got in High School. Unfortunately teaching it went out of fashion and that is partly why we are in the current pickle.
James, Don’t get me wrong I am all for the universal gas laws. Absolutely vital. As a winemaker I am dealing with various gases, buying them in bottles, getting rid of one gas with another, suffering from solubility differences, the expansion and contraction with temperature and so on. In understanding climate one gets nowhere without an understanding of the ability of some gases to trap long wave radiation from the Earth.
Erl,
My post wasn’t really meant as a detraction of your work. You are pointing out there is a pattern and eventually we have to get to the root of how to predict the specifics of this pattern in the future and develop a general mechanism to describe its causes. I like what you have here, but was addressing some of the complaints about endpoints from above posters. I am not even suggesting that you do the plots that way, because you only need to do the plots in a manner that illustrates the points you were making. Most of us can see the pattern wrap around to a nearly identical seasonal pattern year-to-year. Though the advantage of wrap around plots is you can see the effects a large pressure difference in one year can have on the pressure difference in the next more clearly. You weren’t discussing that so it makes sense that you didn’t graph it in that way. Didn’t mean to get pedantic.
Tim Folkerts says: September 23, 2011 at 9:20 am
I agree with everything you say but the most important dynamic is not mentioned.
Atmospheric pressure varies from place to place about the Earth according to the distribution of land and sea, the season and latitude.
I must point out that there is a steep latitudinal gradient in the presence of ozone in the winter hemisphere. Secondly, variability in the night jet over the pole, particularly in winter, due to the introduction of nitrogen oxides from the mesosphere either robs or enables an increase in the concentration of ozone. Ozone absorbs long wave radiation from the Earth.In winter the cold point in the polar atmosphere ascends into the middle stratosphere. A convectional circulation occurs coupling the stratosphere with the troposphere. Ozone is introduced into the troposphere resulting in localized heating, pressure loss and a cloud cover reduction the latter extending towards the equator as ozone is carried equator-wards by the upper atmosphere counter westerlies.
The troposphere contains 70-80% of the weight of the atmosphere. When ozone is introduced into the troposphere it acts as a heat source because it absorbs outgoing radiation at 9.6 micrometres. In the process air pressure is changed globally. The variability in the week to week, month to month, season to season, year to year, decade to decade and lifetime addition of ozone to the troposphere in high latitudes is responsible for the variation in pressure and winds that we observe, a variation in cloud cover and a consequent variation in surface temperature.
Larry Sheehan says: September 23, 2011 at 8:51 am
Thanks Larry, we love chemists. They are really good at the micro stuff. But they should do a couple of units of geography so that they occasionally get to look at the big world outside the test tube. My last comment covers the point.
Tim Folkerts says:
September 23, 2011 at 9:20 am
“……….Net changes in humidity will cause mass to change, which would change the global pressure…….”
===============================================================
So, are we back to discussing clouds?
@ur momisugly Doug S says:
September 22, 2011 at 11:47 pm
Before you rave about mr. Happ’s latest brew, may I suggest you read the first growth first?
“Dynamic Analysis of Weather and Climate Atmospheric Circulation, Perturbations, Climatic Evolution”, Prof. Marcel Leroux, Springer-Praxis books in Environmental Sciences, 2nd ed., 2010, 440p., ISBN 978-3-642-04679-7
Or start with this:
http://ddata.over-blog.com/xxxyyy/2/32/25/79/Leroux-Global-and-Planetary-Change-1993.pdf
Absolutely brilliant work. It is fascinating and fun natural history. (Climate science, when it comes into existence, will be recognized as part of Natural History.)
I have not had time to absorb the science behind this work. But the direction of the work is excellent. Too bad, Happ is not tenured at Harvard because the Warmista will studiously ignore him.
Happ writes:
“There have been a suggestion that some heat that ‘should be there’ has gone missing. Can this be read as an admission that warming has either slowed down or has actually ceased?”
Yes.
It can also be read as an early glimmer of a recognition by Trenberth that on Earth there are natural processes other than radiation and that it can happen that radiation has to work its way through these natural process before its effects can be understood. Time to get out of the supercomputer lounge and into the world for empirical research on La Nina.
I have been arguing for years that ENSO is a natural process that must be understood in its own terms and not dismissed by Warmista as an epiphenomenon of radiation.
Erl, have you any idea why the switch in relative positions occurs around 1997.1998?
Erl
What you need to add in your explanation to Chris Korvin is that the clouds are manifestation of the latent heat being transported from the surface to high in the atmosphere where water vapor condenses.
The condensation releases the heat forming clouds that reflect incoming heat from the sun.
If the convection is strong enough the clouds continue to rise and the water freezes releasing yet more latent heat that was originally from the surface.
At night the convection reduces and the clouds slowly evaporate or sublimate away the clearing skies allow more direct radiation from the surface.
(I think that sums up Willis’ Hypothesis 😉 )
Atmospheric shifts increase wind – leading to increased evaporation transporting heat from the surface – leading to increased cloud cover leading to less incoming heating.
GCR may assist in providing cloud condensation nuclei in saturated air aiding the formation of clouds.
If ‘Climate Science’ were not a PC Cargo-Cult,
such trenchant scientific work would not have been left
to a lone, self-funded oenophile (Bless his industrious heart!)
Hansen would have done all this back in the ’70’s
and then gone before Congress that fateful hot day in 1980
to testify ‘Whew! No Problem!’
(This has to be the most radical alternate history ever proposed.
Imagine, the idea of an honest govt-scientist not being a quasi-oxymoron!)
Wasn’t all of this predicted by the work of Robert Brown (and used daily in the form of modern air conditioning) ?
Sorry to rain (ha-ha!) on your parade, you who cite the Ideal Gas Law as if holy writ, but the Earth’s atmosphere is not an ideal gas. The ideal gas law does not apply when the system includes evaporation and condensation.