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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Paul,
Can you be less abstract. You might as well be talking in tongues. What for instance does this mean?
“It’s a sampling & aggregation problem.” What is ‘its”
and
“You’re effectively chasing relations between eddies & back-eddies.” What is a back eddy. Where is the main stream?
and
“I’m suggesting you look OUTSIDE the box (which is constrained at a GLOBAL scale).”
What is the box? How is it constrained?
“I sternly advise you to understand Milanovic’s primary point.”
Be as stern as you like but if you can not tell me what his primary point is in a fashion that is meaningful to me you are wasting your time.
Rest assured I that I respect the skills that you bring to the discussion and I am anxious to comprehend what you are saying. I do not willingly misinterpret or ignore fundamentals. I am simply unable to identify what these fundamentals are.
I know what sampling is and I know what aggregation is but of what?
Erl, once a back-&-forth gets to 3 rounds in a single thread, I’ve had enough (resolution or not). There will be other threads. Thanks.
Erl Happ: In response to my comment in which I asked you to document your claim that I have failed to identify the filters used, and have mixed filters, in my graphs, you replied, “My point related not to mixing but simply to the identification of the smoothing. I see no reference to the smoothing or lack of it in figures 2 and 3 of the post that I was directed to.”
There was no smoothing in Figures 2 and 3 in my post:
http://bobtisdale.wordpress.com/2011/07/26/enso-indices-do-not-represent-the-process-of-enso-or-its-impact-on-global-temperature/
And there’s no reason for me to identify a lack of filtering.
You said, “What I am concerned with is not degrees of accuracy but the linkage between variables. The magnitude of change is not as important as the direction and whether one variable is related to the other.”
I understand. But IMHO the modeled portions of the NCEP reanalysis should be verified with other reanalysis to determine if there is a consistency between how the modelers represent those variables. In other words, you’re putting all of your research into model outputs that may or may not represent reality.
Thanks for the link to Trenberth et al (2005).
In response to my comment about your use of absolute data and it masking the magnitude of the rise in temperature, you replied, “All data streams involve smoothing and in monthly data its already massive. I used the NCEP generated graphs because they give more information and they enable people to keep a sense of perspective…”
You apparently missed the point of my comment. For those following this discussion, it pertained to this post…
http://wattsupwiththat.com/2011/08/16/the-character-of-climate-change-part-2/
…and this graph, as the first example…
http://climatechange1.files.wordpress.com/2011/08/air-t60n-50s-august.jpg
…and this text from that post, “In 2008 and 2011 winter minima are almost as cool as those experienced during the period of cooling between 1948 and 1976.”
I duplicated your surface temperature graph from 0-60N at the NCEP website:
http://i53.tinypic.com/10qdtt2.jpg
But I also downloaded the data so that I could plot the annual minima for that dataset. And as you can see, the 2008 and 2011 are nowhere near the levels reached between 1948 and 1976:
http://i55.tinypic.com/331ev5j.jpg
Returning to your graph, it was very obvious that you did not center the ellipse you used to highlight the last few years of minima. You extended it well below the data points for those years. That sleight of hand was a very obvious attempt to force the illusion that the recent minima were near the levels of 1948 to 1976. They are not.
Now let’s look at your Southern Hemisphere graph:
http://climatechange1.files.wordpress.com/2011/08/air-t-sh-0-50s.jpg
I again duplicated your results:
http://i55.tinypic.com/s30jn5.jpg
To your graph, you’ve added those misleading flat lines from 1978 to present, and about it, you’ve written, “A plateau was maintained between 1978 and 2011 as temperature in the northern hemisphere increased strongly.”
There was no plateau in the annual maximum and minimum for the Southern Hemisphere Surface Temperatures from 1978 to present, Erl. Anyone who looked past the flat lines you added can see that. To help illustrate this fact, I again downloaded the data associated with the NCEP reanalysis graph. Here are the annual maxima…
http://i51.tinypic.com/u8snp.jpg
…and annual minima…
http://i56.tinypic.com/64lcv5.jpg
…plotted separately, with the linear trends from 1978 to 2011 added to both. During the periods that you identify as a plateau and highlighted with flat lines, the annual maxima data rose are at rate of 0.051 deg C per decade and the annual minima rose are a rate of 0.049 deg C per decade. Those trends are not insignificant.
Again, as I wrote in my earlier comment: The AGW debate is over a few 10ths of the degree C, and the scale you’ve used for the absolute data masks the significance of this.
By using the absolute data and adding your circles and flat lines, you’re misleading yourself and you’re misleading your readers.
Regarding my mark-up of and comment about your Figure 126…
http://i52.tinypic.com/29geoh0.jpg
…you rep lied, “You choose to misinterpret what I said. I did not say that La Nina events are confined to solar maximum or that El Nino events are confined to solar minimum.”
What you did write in the post was, “2000 was a La Nina year coinciding with solar maximum. A coincidence of La Nina with solar maximum is more usual than not.” But in reality, there is no coincidence of La Niña with solar maximum. You are again attempting to mislead yourself and your readers.
In response to my comment, ”The first reference you sent me to, Erl, is erroneous. Not a good sign,” you replied, “Which was that? I would like to check it out. In what respect was it erroneous?”
It was your representation of La Niña events coinciding with solar maxima “is more usual than not,” and the link you provided to your Figure 126 from your pdf. But we can add the graphs from your “The character of climate change part 2” post discussed above in this comment if you like.
I wrote earlier, “Please provide a link to the paper that identifies the source of the SST data for the ‘Kalnays reanalysis’ at the NCEP website, from which you can make that curious ‘and it is a lot more volatile than the data you access’ statement,” since I had identified the NCEP uses the same SST datasets that I use, but you chose to provide an explanation that had nothing to do with that request. In other words you cannot document your earlier comment that the “Kalnay” SST data provided by the NCEP “reflects skin temperature rather than SST beneath the surface and it is a lot more volatile than the data [I] access”. It’s the same data, Erl.
You started your comment with, “Bob, your tone is harassing. If I provoke that response I must apologize”
It is not intended to be harassing. I’m simply presenting my findings and adding commentary as I feel necessary.
Getting ready for the next thread — this is a test:
Erl or anyone else:
Can you access the following links?
1. http://xa.yimg.com/kq/groups/21705507/or/2144438090/name/AnimPolarWind200hPa.png
2. http://xa.yimg.com/kq/groups/21705507/or/1600750484/name/AnimWind200hPa.png
Bob, in my last comment I posted links to APNGs. Do those animations play properly for you? Thanks.
No go Paul
Paul, the links to the animations provide a “HTTP 403 Forbidden” response.
Bob, I applaud you for the level of precision you achieve. But I think you are missing the wood for the trees. There is a very obvious difference in the thermal experience of the two hemsipheres. I don’t want to trade blows with you on minutae. It will be never-ending. I too could plot the maxima and minima and magnify the scale so that the changes look mind bogglingly large.
The coincidence of solar max with a La Nina orientation has been noticed by others. First Harry Van Loon and after him Meehl. If you insist on pinpoint accuracy how do you deal with a sunspot cycle like 23 with two maxima or 24 that according to Leif will have about four.
And I guess the chief point from those two posts is that both hemsipheres, and in particular the southern have a temperature regime that is sub optimal for plant growth……and human welfare and that we would all be better off if the temperature were several degrees warmer and growing seasons were longer. So, I think that if the global warming debate is all about a few tenths of a degree we are misplacing our priorities. That we are concerning ourselves with this nonsense represents a tragic waste of time. Would that it were unnecessary.
Having looked at the Trenberth paper is it not apparent that the Southern Annular Mode is the chief source of variation in climate? Is it conceivable that it is affecting the strength of the trade winds and affecting the base state in the tropics? Since its all about change in surface pressure is it not of interest that tropical SST follows the SOI, a pressure based statistic. What is it about pressure that delivers this relationship with surface temperature. These are the questions worth worrying about.
Alternatively hows your share portfolio or your super fund looking?
Bob, I applaud you for the level of precision you achieve. But I think you are missing the wood for the trees. There is a very obvious difference in the thermal experience of the two hemsipheres. I don’t want to trade blows with you on minutae. It will be never-ending. I too could plot the maxima and minima and magnify the scale so that the changes look mind bogglingly large.
The coincidence of solar max with a La Nina orientation has been noticed by others. First Harry Van Loon and after him Meehl. If you insist on pinpoint accuracy how do you deal with a sunspot cycle like 23 with two maxima or 24 that according to Leif will have about four.
And I guess the chief point from those two posts is that both hemsipheres, and in particular the southern have a temperature regime that is sub optimal for plant growth……and human welfare and that we would all be better off if the temperature were several degrees warmer and growing seasons were longer. So, I think that if the global warming debate is all about a few tenths of a degree we are misplacing our priorities. That we are concerning ourselves with this nonsense represents a tragic waste of time. Would that it were unnecessary.
Having looked at the Trenberth paper is it not apparent that the Southern Annular Mode is the chief source of variation in climate? Is it conceivable that it is affecting the strength of the trade winds and affecting the base state in the tropics? Since its all about change in surface pressure is it not of interest that tropical SST follows the SOI, a pressure based statistic. What is it about pressure that delivers this relationship with surface temperature. These are the questions worth worrying about.
Alternatively hows your share portfolio or your super fund looking?
erl happ: You wrote, “Bob, I applaud you for the level of precision you achieve. But I think you are missing the wood for the trees. There is a very obvious difference in the thermal experience of the two hemsipheres. I don’t want to trade blows with you on minutae. It will be never-ending. I too could plot the maxima and minima and magnify the scale so that the changes look mind bogglingly large.”
I’ve illustrated to you that your presentations of the data in those two surface temperature graphs (from the post you asked me to look at) are fatally flawed, and you call it minutia and somehow think the scaling I’ve used makes a difference. The facts are, the Northern Hemisphere Minimum Surface Temperatures in 2008 and 2011 are not close to the levels they were at during the cooling period from 1948 to 1976, as you had represented, and the Southern Hemisphere Minima and Maxima are not flat since 1978, as you had represented. Linear trends of 0.05 deg C over 30 plus years are not flat.
Your statement that there “…is a very obvious difference in the thermal experience of the two hemsipheres…” is irrelevant to our discussion. It’s widely understood that the Northern Hemisphere surface temperatures have had greater variations over the term of the instrument temperature record than the Southern Hemisphere. This doesn’t change or justify how you’ve misrepresented the data with those graphs.
You wrote, “The coincidence of solar max with a La Nina orientation has been noticed by others. First Harry Van Loon and after him Meehl.”
Are your referring to van Loon and Meehl (2008), “The response in the Pacific to the sun’s decadal peaks and contrasts to cold events in the Southern Oscillation”?
http://www.cgd.ucar.edu/ccr/publications/vanloon_meehl_2008.pdf
That paper discusses how the responses of numerous Pacific Ocean variables to Solar Maxima are similar in some respects to La Niña events, but different in others. It does not conclude that La Niña events coincide with Solar Maxima.
Hmm. I believe you are referring to that paper. You referenced it at the end of your 196-page discussion titled “The Origin of Climate Change.”
http://www.happs.com.au/images/stories/PDFarticles/TheCommonSenseOfClimateChange.pdf
You wrote, “Having looked at the Trenberth paper is it not apparent that the Southern Annular Mode is the chief source of variation in climate?”
I believe your overstating the conclusions of Trenberth et al (2005) “Interannual Variability of Patterns of Atmospheric Mass Distribution.”
http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/massEteleconnJC.pdf
Their conclusions are based on multiple types of EOF analyses of the ERA40 reanalysis data. You could discuss the advantages and disadvantages of these EOF analyses with Paul Vaughan. But in opposition to your emphasis on the SAM. Trenberth et al also note, ending their paper with, “For monthly data, ENSO comes in as the second mode, and it is global in extent. However, it also exhibits more coherent evolution with time and projects strongest onto the interannual variability where it stands out as the dominant mode in the CSEOF analysis. As shown, it is coherent with Niño-3.4 SSTs and thus is a coupled mode. This analysis establishes these modes and their ranked importance in more rigorous ways than has been done in the past.”
In some respects, to me, this means that ENSO is the dominant mode of year-to-year Global climate variability, no surprise there, and if I wanted to look for a source of the month-to-month noise, I should look to the Southern Annular Mode. But that, of course exhibits my confirmation bias, since one of my areas of research is ENSO. Are you expressing your confirmation bias with respect to SAM?
Bob you got the Van Loon paper in one.In sending me the paper Harry commented: “The funny thing, which disturbs many colleagues, is that at the PEAKS in the 11-year cycle the equatorial Pacific cools, though not to the extreme values of the low SSTs in the Southern Oscillation.”
You say
“Your statement that there “…is a very obvious difference in the thermal experience of the two hemispheres…” is irrelevant to our discussion. It’s widely understood that the Northern Hemisphere surface temperatures have had greater variations over the term of the instrument temperature record than the Southern Hemisphere. This doesn’t change or justify how you’ve misrepresented the data with those graphs.”
Not irrelevant at all. I don’t think it is good physics to suggest that the thermal experience in the tropics drives the very different thermal experience in both hemispheres. So the question is: what drives it. We have just one tropics, just one Pacific ocean but two poles . I suggest that you have a close look at the dynamics of the coupled circulation of the stratosphere and the troposphere at the poles. That in Antarctica drives the distribution of the atmosphere globally. So it is directly responsible for surface pressure change.
SST in the mid latitudes of both hemispheres rises and falls with the differential pressure driving the westerly winds. The differential pressure driving the winds changes according to change in Antarctica and the Arctic.
The matter under discussion in this post is why does temperature change as it does, and what has atmospheric pressure got to do with it. You began by asserting that the change in the SOI was a result of ENSO processes. My post pointed to the underlying upward trend in figure 13. At issue is what is causing the upward trend.
You ask: “Are you expressing your confirmation bias with respect to SAM?”
I know how important SAM is in determining the winds globally. And I cannot agree that tropical processes could cause the massive loss of surface atmospheric pressure that we have seen in Antarctica over the last sixty years. That loss of pressure is at the root of the increase in surface pressure in the global tropics and in Darwin. But, the pressure differential between Tahiti and Darwin has increased over the last twenty years indicating a change in the base state. As pressure falls south of 50° south it rises strongly between the equator and 40° south with a bias to the south. So, the increase in the differential between Tahiti and Darwin is to be expected. So I would look specifically at the high pressure cell in the south east Pacific east of Chile (figure 3 and 4 above) that takes in Tahiti on its margins and look at the historical trend. It is not ENSO that changes surface pressure in the South East Pacific it is SAM.
Thank you for participating Bob. Discussion helps to clarify the mind, it makes us re-examine our assumptions and refine our methods and presentations. It’s all good.
Erl, I found this towards he end of your 196 page pdf:
“Cloud cover will increase as the stratosphere cools. There is a lot of cooling to be
accomplished before the southern stratosphere returns to the temperature of 1948, or
perhaps even 1812 when Napoleons troops evacuated a frozen Russia. This process will be
driven by rising polar pressure reinvigorating the night jet bringing erosive compounds from
the mesosphere to deplete stratospheric ozone.”
However in fact cloud cover has been seen to INCREASE as the stratosphere WARMED since about 2000 and seen to DECREASE as the stratosphere COOLS as during the late 20th century warming spell.
I think the reason is revealed by the effect of short term events such as sudden stratospheric warmings. Such events drive the air circulation pattern equatorward and/or make the jets more meridional which gives more cloudiness rather than less.
I think you are on the right track overall but that you have to go to a lot of convolutions that might be unnecessary if you acknowledge that point and work it into your narrative.
That is also why the consensus view of a warming stratosphere with an active sun and cooling stratosphere for an inactive sun cannot be right IMHO.
My view is supported by the Joanna Haigh announcement that above 45km ozone actually INCREASED from 2004 to 2007 DESPITE the less active sun and the fact that the cooling of the stratosphere ceased in the late 90s with signs now of a slight warming.
I do support your general contention that there is a top down polar effect on surface air pressure distribution which the ENSO phenomenon cannot be responsible for driving and which I agree must be influenced by the level of solar activity.
As for Bob’s points about a couple of your graphs being ‘misleading’ or ‘flawed’ I wonder whether you would need them at all if you were to rejig your proposals to accord with the reversed sign effect that I mention.
Of course, if the stratosphere suddenly starts cooling again whilst the sun stays inactive then I will be proved wrong but I wouldn’t recommend anyone holding their breath in the meantime 🙂
Stephen Wilde says: September 26, 2011 at 7:17 pm
Congratulations on your persistence with my PDF.
You say: However in fact cloud cover has been seen to INCREASE as the stratosphere WARMED since about 2000 and seen to DECREASE as the stratosphere COOLS as during the late 20th century warming spell.
We must be careful to define which part of the stratosphere we are talking about. We have to distinguish the pressure level and the hemisphere and whether we are talking low, middle or high latitudes.
Some of the forces involved as I understand them:
1. The equatorial lower and middle stratosphere warms as the upwards flow of water from the troposphere diminishes.
2. The upper stratosphere warms and cools with solar activity if we speak in a general fashion as short wave radiation splits ozone producing more free oxygen molecules to combine to form ozone.
3. The upper stratosphere at the poles warms or cools according to night jet activity.
4. The temperature of the southern stratosphere and its ozone content depend upon the Antarctic circulation that wastes it into the troposphere.
5. The temperature of the mid latitude stratosphere depends upon how much ozone is wasted into the troposphere by air descending into high pressure cells. These cells have become more active over time.
6. see below.
You can work out what has happened to the temperature of each part of the stratosphere without downloading data by choosing the graphing option here:http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl If you can’t work it call me on skype and I will talk you through it.
The most influential force determining cloud cover is polar atmospheric pressure. As pressure increases the night jet is more active and ozone is destroyed. The temperature of the upper stratosphere at the poles declines, less ozone is bled into the troposphere by the coupled circulation at the poles, upper troposphere temperature declines and as it does so cloud cover in the troposphere increases.
Re: Joanna Haigh announcement that above 45km ozone actually INCREASED from 2004 to 2007
6. from above. At the interaction zone of stratosphere and mesosphere the concentration of NOx in the mesosphere affects ozone concentration. NOx concentration declines with solar geomagnetic activity thus allowing ozone to build up and temperature to increase.
So, its much more complex than you think.
Actually Erl, I think it may be less complex than one might think.
However the stratospheric temperature changes are distributed what counts is the relative tropospheric heights between poles and equator.
If the polar regions cool above 45km from a more active sun more than the equatorial regions warm below 45km from a more active sun then the gradient from equator to poles will change and the surface air pressure systems will drift poleward.
I agree that the key level is at or near the stratopause where Haigh seems to suggest that the solar effect reverses and in light of that I propose that the thermal effect in the mesosphere dominates over the thermal effect on the stratosphere for a reverse sign effect in the stratosphere too.
So the variable net solar effect between mesosphere and stratosphere operates a sort of see saw with the fulcrum at about 45 degrees latitude in eacxh hemisphere and as the thermal effects vary between active or inactive sun the balance of the atmosphere in each hemisphere moves poleward or equatorward as necessary to maintain the overall global energy budget by altering the rate of the net energy flow from surface to space.
From the surface we see the permanent climate zones drift first one way and then the other and that is pretty much all that climate change is.
Stephen,
“From the surface we see the permanent climate zones drift first one way and then the other and that is pretty much all that climate change is.”
That is the annual cycle.
Over decades the pressure belts move in response to:
1. The energy going into the Hadley cell at the equator
2. The waxing and waning of the coupled circulation in Antarctica.
Sorry, I can not see the thing you are describing.
During the LIA the mid latitude jets were south of their present positions and presumably during the MWP similar to now or possibly even more poleward.
So I am looking at a 1000 year cycle peak to peak or trough to trough. A multicentennial variability but no doubt also affected on shorter timescales by individual solar cycles and the Pacific Multidecadal Oscillation of 60 years or so. The shorter the timescale the more the multicentennial underlying trend is masked by those other variations and by chaotic variability.
I think it is driven from above by solar effects on the atmosphere due to the correlation with solar changes observed from around 1600 to date.
As regards items 1 and 2 that you mention I think that they respond to the interplay between top down solar and bottom up oceanic variations but for the purpose of your work we are currently discussing the top down solar component.
Ask yourself this:
Why would sudden stratospheric warming events cause polar air to surge towards the equator if a warm stratosphere at a time of an active sun is supposed to allow the jets to move more poleward ?
Why, now that the stratosphere has stopped cooling and may now be warming at a time of relatively quiet sun, are we seeing more meridional/equatorward jets ?
The observation of what happens during sudden stratospheric warmings and at a time of quiet sun is inconsistent with the standard theory.
erl happ says: “Bob you got the Van Loon paper in one.In sending me the paper Harry commented: ‘The funny thing, which disturbs many colleagues, is that at the PEAKS in the 11-year cycle the equatorial Pacific cools, though not to the extreme values of the low SSTs in the Southern Oscillation.’”
And the comment from Harry (van Loon) does not confirm your statement from the post that La Nina events coincide with Solar Maximums.
In response to my comment “Your statement that there ‘…is a very obvious difference in the thermal experience of the two hemispheres…’ is irrelevant to our discussion…” you replied, “Not irrelevant at all…”
My comments on this topic pertain primarily to your misrepresentation of data in the two graphs. The additional topics you elect to interject appear to simply be a smoke screen to hide that fact.
You replied, “The matter under discussion in this post is why does temperature change as it does, and what has atmospheric pressure got to do with it. You began by asserting that the change in the SOI was a result of ENSO processes. My post pointed to the underlying upward trend in figure 13. At issue is what is causing the upward trend.”
What’s causing the upward trend? The answer is very obvious, you’ve actually answered that in your post, but you obscured it by plotting 12 months of average daily SOI values for those three periods. By doing so, you’ve complicated a very basic analysis. All you have to do is pick an ENSO index of your choice and plot the times series from 1992 to 2011, breaking the data up into the three periods you elected to use, (without explaining why you selected them). Here’s NINO3.4 SST anomalies for example:
http://i53.tinypic.com/fmkgf9.jpg
The period of 1992 to 1997 was dominated by El Nino events, the period of 1998 to 2004 was a mix of El Nino and La Nina events with the average NINO3.4 SST anomaly being close to zero, and the period of 2005 to 2011 was dominated by La Nina events. Simple as that, Erl. And if you were to do a similar analysis from 1973 to 1997, breaking that into three periods, you’d find that the NINO3.4 SST anomalies trended upwards (or SOI trended downwards). There’s a decadal/multidecadal component to ENSO, Erl. You know that.
Why complicate something so simple? And on that question, I will bid you a fond farewell on this thread.
Here I agree with Bob Tisdale as regards the ENSO effect on periods up to about 60 years. I really do not see any tendency for La Nina to be dominant when the solar cycles are at maximum.
There is a reason why Erl might think it necessary. La Nina represents a witholding of energy by the oceans so ocean heat content should increase and indeed ocean heat content did increase whilst the sun was active in the late 20th century. However we also had a run of strong El Ninos during that period so another explanation is needed.
I prefer the view that the poleward shift of the surface air pressure systems allowed more solar energy into the oceans than was lost even by that strong run of El Ninos.
In addition it remains necessary to explain the upward stepping from one positive phase of the Pacific Multidecadal Oscillation (not PDO) to the next and it is there that Erl’s work could be useful.
Unfortunately neither Bob nor Erl seems to be looking at the global climate cycling from MWP to LIA to date let alone the Roman Warm Period and the Dark Ages.
If one were to integrate Erl’s work on the upper atmosphere with Bob’s work on ENSO variability but extend both to a peak to peak timescale of 1000 years then that could be progress but to produce the stratospheric temperature changes actually observed plus the observed effect on the surface air pressure distribution Erl (IMHO) would need to abandon the consensus view and embrace a reversed sign temperature effect in the atmosphere above the tropopause.
The two main problems for Erl are as foillows:
i) The stratosphere cooled when the sun was more active.
ii) The ocean heat content increased despite strong El Ninos whilst the sun was more active.
A workable hypothesis must deal with both those problems AND fit all other observations including the observed latitudinal jet stream shifting, the declining cloudiness and albedo during the late 20th century and the subsequent recovery, the stalling of the rise in global tropospheric temperatures to point up just a few.
Stephen Wilde says: “Unfortunately neither Bob nor Erl seems to be looking at the global climate cycling from MWP to LIA to date let alone the Roman Warm Period and the Dark Ages.”
And you continued, “If one were to integrate Erl’s work on the upper atmosphere with Bob’s work on ENSO variability but extend both to a peak to peak timescale of 1000 years then that could be progress but to produce the stratospheric temperature changes actually observed plus the observed effect on the surface air pressure distribution Erl (IMHO) would need to abandon the consensus view and embrace a reversed sign temperature effect in the atmosphere above the tropopause.”
You well aware that there’s no reliable data to use, so there’s no reason that you should continue to raise this topic and attempt to make Erl and I appear to be negligent in our research..
Bob Tisdale says: September 27, 2011 at 3:57 am
Bob, I am not into smoke screens.
You say:
What’s causing the upward trend? The answer is very obvious, you’ve actually answered that in your post, but you obscured it by plotting 12 months of average daily SOI values for those three periods. By doing so, you’ve complicated a very basic analysis. All you have to do is pick an ENSO index of your choice and plot the times series from 1992 to 2011, breaking the data up into the three periods you elected to use, (without explaining why you selected them). Here’s NINO3.4 SST anomalies for example:
http://i53.tinypic.com/fmkgf9.jpg
The period of 1992 to 1997 was dominated by El Nino events, the period of 1998 to 2004 was a mix of El Nino and La Nina events with the average NINO3.4 SST anomaly being close to zero, and the period of 2005 to 2011 was dominated by La Nina events. Simple as that, Erl. And if you were to do a similar analysis from 1973 to 1997, breaking that into three periods, you’d find that the NINO3.4 SST anomalies trended upwards (or SOI trended downwards). There’s a decadal/multidecadal component to ENSO, Erl. You know that.
What is the decadal/ multidecadal component in ENSO due to Bob? A lot of people would deny that it exists. The literature won’t help you.
I don’t think I obscured anything by pointing out the annual cycle in the pressure differential between Tahiti and Darwin. It’s worth knowing that the pressure differential peaks at the end of the year and it is the failure to reach a peak at that time that is the essence of an El Nino. I think it is worth knowing that the pressure differential is rarely actually negative and if it is so it tends to be negative in the middle of the year. I think it helps to know the structure that we see at the moment and to actually go back and compare today’s structure with that of the early years, and they ARE different. The literature suggests that April is a difficult time for forecasting and you can see in this annual structure that it is a frequent transition point between one phase and another. I think its worth using daily data because it shows the extent of the swings in the pressure differential, something that you don’t see in the SST indexes.
Another point about the annual structure. The global surface temperature is least in January and it is at this time that global cloud cover reaches its peak. The time at which sea surface temperature sees its greatest fluctuations is in January. That strongly suggests that change in cloud cover is involved. If it is, one should go look for the parts of the ocean that show this variability in January.
That leads to another question: What known climate oscillation sees its greatest inter-annual variation in November to March? Could that mode be forcing ENSO? Research at NOAA a year ago pointed towards just that possibility. Sorry, I have lost the reference. It wasn’t worth keeping because they couldn’t make up their minds whether ENSO was forcing the AO or it was the other way round. This is the problem with statistical analysis when unenlightened by an appreciation of atmospheric dynamics, cause and effect.
I am not interested in smoke screens Bob. The reverse is the case.
What does it mean? It means that we (Earth) and all the sun heliosphere are experiening a condensed version. Like you take spun cotton candy and squeeze it, it becomes more compact. Taking that a little further this condensed version of Sol’s heliosphere would mean that the compact form is just this little ball surrounding Sol, baring Jupiter, etc., to the cosmic (truly cosmic) wind.
It means this happens periodically as we humans ‘discover’ things like quasicrystals (already long discovered but ‘forgotten’ as to meaning), the ‘discovery’ of Mars supersaturated atmosphere due to this pressurizing event (not to the lack of dust particles for the water vapor to settle out on), and other endless ‘discoveries’ that are not discoveries at all, just repeating events which our past selves may have witnessed with more understanding than we are evidencing.
A clearer eye is needed to avoid hubris.