tallbloke:

An excellent article by E.M. Smith, the ‘Chiefio’


.

Originally posted on Musings from the Chiefio:

The title is a bit of a play on words. In common U.S. English, there’s a frequent phrase that came, I think, from High School Sports (and eventually made it into movies). In one movie, it involves cats vs. dogs. “Cats Rule, Dogs Drool”.

But I could have causality backwards here. Perhaps the movie came first?

At any rate, this posting has two ‘themes’, if you will. First, the Tropopause dominates what happens (i.e. it “rules” while the rest of the atmosphere is along for the ride). Second, that there are things that drive the tropopause, just like there are “rules of the road”, there are physics rules that tell us how the tropopause will behave. Two sides of one coin. What are the rules that drive the tropopause, and why does that dominate the meaning of the air?

Atmosphere, Stratosphere, Mesosphere, Troposphere

My kingdom for a sphere…

We all…

View original 4,806 more words

Comments
  1. Tim Cullen says:

    A really excellent article!

  2. Stephen Wilde says:

    It’s all coming together isn’t it.

  3. Hans Jelbring says:

    I just commented E.M.Smith on another thread. See December 12, 2012 at 8:59 am http://tallbloke.wordpress.com/2012/12/11/a-short-lesson-in-simple-logic/#comment-37998

  4. tallbloke says:

    Hans says:
    there are some very important aspects he is missing.

    o The existence and actions of Mobile Polar highs are very important. The mechanism
    that drives them is for real and not recognized by mainstream meteorologists.

    Hans:
    I think E.M Smith did refer to MPH’s in his article here:

    “Along the way, a very cold stratosphere, dropping down the winter Polar Vortex, will cause a fairly strong warm / cold range between poles and the equator. That will cause a ‘loopy jet stream’ as the blobs of cold arctic air slide south and plenty of winter storms as the equatorial heat heads north. Only running down when we’ve cooled the tropics enough to balance the colder poles.”

    A friend has sent me Leroux’s two books. A fabulous early christmas present. So you can expect posts discussing his work once I’ve had time to read parts of them over the Christmas holiday.

  5. Hans Jelbring says:

    tallbloke says: December 12, 2012 at 9:47 am

    To refer to the Ferrel cell and the Hadley cell is to believe earth energy economy is ruled by a steady state system. Oddly enough this is a model that I also favour seen from a global perspective during many years. However, a spatial 8regional) steady state model in the troposphere is rather often (mostly during wintertime) interrupted by Mobile Polar Highs which suddenly make the model Ferrel and Hadley cells an academic interest. This is the main reason why I claimed E.M. Smith missed the importance of the impact of Moblie Polar Highs. I missed the sentence you are referring to and I apologize in that respect.

    If you are going to read Leroux´ books we cannot expect to hear very much from you in about a month. When you have finished I might find the thesis of his pupil Alexis Pommier which deals with the motion of MPHs in the North Atlantic (300 more pages of interesting reading).

  6. Hans Jelbring says:

    tallbloke says: December 12, 2012 at 9:47 am

    E.M. Smith says:
    “Along the way, a very cold stratosphere, dropping down the winter Polar Vortex, will cause a fairly strong warm / cold range between poles and the equator. That will cause a ‘loopy jet stream’ as the blobs of cold arctic air slide south and plenty of winter storms as the equatorial heat heads north. Only running down when we’ve cooled the tropics enough to balance the colder poles.”

    To me it not quite obvious what is meant by this paragraph? Here is my take of the situation: The cold air masses in polar areas are caused by long and excessive IR radiation to space (mostly from ground). If and only íf they can be created during a long time (week or more) and stay in place they will form impressive MPHs. Otherwise the cold air will “leak” equatorwards in a slower manner. When such an MPH starts moving it will affect the Jet Stream and put it equator wards. The MPH starts moving because of latitudinal pressure difference along a surface with constant gravitational potential (think ocean surface). The maximum acceleration will be at latitude 45. The warming of an MPH along its motion will slow down its acceleration to some degree. This motion is driven by the centrifugal force and has little to do with the temperature at the equatorial zone. The cold air (MPH) stops moving when reaching the equatorial region since there is no more force accelerating it. This force has not been recognized by main stream climatologists. Marcel Leroux never tried to publish anything about the physics behind the motion of an MPH. He concentrated on describing them. He did ponder about if the physical reason was coming from above or from below and favored the latter idea. I suggested this solution in my thesis (page 20) and named it “Horizontal Density Forcing” and Marcel was well aware of my work.

  7. Hans Jelbring says:

    tallbloke says: December 12, 2012 at 9:47 am

    E.M. Smith says:
    “Along the way, a very cold stratosphere, dropping down the winter Polar Vortex, will cause a fairly strong warm / cold range between poles and the equator. That will cause a ‘loopy jet stream’ as the blobs of cold arctic air slide south and plenty of winter storms as the equatorial heat heads north. Only running down when we’ve cooled the tropics enough to balance the colder poles.”

    To me it not quite obvious what is meant by this paragraph? Here is my take of the situation: The cold air masses in polar areas are caused by long and excessive IR radiation to space (mostly from ground). If and only íf they can be created during a long time and stay in place they will form impressive MPHs. Otherwise the cold air will “leak” equator wards in a slow manner. When such an MPH start moving it will affect the Jet stream and put it equator wards. The MPH starts moving because of latitudinal pressure difference along a surface with constant gravitational potential (think ocean surface). The maximum acceleration will be at latitude 45. The warming of an MPH along its motion will slow down its acceleration to some degree. This motion is driven by the centrifugal force and has little to do with the temperature at the equatorial zone. The cold air (MPH) stops moving when reaching the equatorial region since there is no more force accelerating it. This force has not been recognized by main stream climatologists. Marcel Leroux never tried to publish anything about the physics behind the motion of an MPH. He concentrated on describing them. He did ponder if the reason was coming from above or from below and favored the latter idea. I suggested this solution in my thesis (page 20) and named it “Horizontal Density Forcing” and Marcel was well aware of my work.

  8. oldbrew says:

    For anyone who hasn’t read the link, note this quote from it:

    ‘in the troposphere, water is everything and CO2 is nothing’

  9. Stephen Wilde says:

    Note that one does seem to need a warmer stratosphere above the poles (relative to that above the equator) in order to give the polar air masses a push equatorward.

    That warmer stratosphere pushes the polar tropopause height down to give the surface air masses a kick.

  10. Hans Jelbring says:

    To go back to the title: Tropopause rules

    Troposphere rules is a better title in my opinion.
    A major simplified model of earth´s atmosphere is to consider it as an energetically steady state system but closed with respect to flow of matter. This means that the amount of energy flux that comes in will also go out. We know this isn´t true, especially not on a regional basis at a specific season. Anyway, it is a good model for highlightning a special feature of the atmosphere.

    The atmosphere holds a certain amount of energy a fact which should be unquestionable. The way this energy is distributed is a function of gravity. If we close the atmosphere this is easier to understand (See my two earlier Tallbloke posts). In that situation the available energy in the closed atmosphere have to be distributed equally in any macroscopic air parcel of an equal mass (about a billion molecules). The temperature lapse rate in such a situation would be exactly -g/Cp where g is gravity (m/s^2) and Cp is J/(kg K).

    This is an approximate solution to the situation in a real atmosphere especially in equatorial and mid latitude regions on earth. The second law of thermodynamics properly considering the distribution of energy (instead of temperature) is what is governing the temperature in earth´s troposphere. This is not the situation in the stratosphere where other (mostly radiative) physical processes dominate. But since the bulk of mass and stored energy is found in the troposphere there are reasons to say: The energy distribution in the troposhere rules and the deviations from a stready state are of minor influence regarding temperature distribution in the lower atmosphere of earth. The last statement is more adequate in the Venusian atmosphere which is much denser and less accurate in the Martian one which is much thinner.

  11. Max™‮‮ says:

    Huh, I thought it was a reference to The Cider House Rules…

  12. Hans Jelbring says:

    Stephen Wilde says: December 12, 2012 at 11:27 am

    “Note that one does seem to need a warmer stratosphere above the poles (relative to that above the equator) in order to give the polar air masses a push equatorward.
    That warmer stratosphere pushes the polar tropopause height down to give the surface air masses a kick.”

    Since the tropopause is lower at the poles air moves from equatorial areas (it “falls” down) to the poles and subside. Subsidence means that the temperature when moving downwards increase and a constant inversion develops above the low cold troposphere created by IR radiation from the surface. This is the major physical process making equatorial energy reaching the polar areas at all.

    Steven, the atmosphere tries to keep the atmospheric pressure at the surface equal all around the globe. That pressure can be calculated as M/g(effective) where M is mass over a square meter and g(effective) is the measured gravity at the any place. The centrifugal force makes g at the equator (9.78) less than gravity at the poles (9.85). What decides how long time a cold polar air mass stays in place before moving depends on some factors. What decides if an MPH starts moving is primarily IMO its density in the lower troposphere, topography (mountain ranges) and the tidal impact of our moon (extraterrestrial influence).

  13. Stephen Wilde says:

    Hans.

    I agree with all that.

    I was thinking of longer term cyclical changes whereby over time the stratosphere warms or cools as a result of solar variation weakening or intensifying the polar vortices.

    A positive AO and AAO when the sun is active and a more negative AO and AAO when the sun is less active.

  14. Hans Jelbring says:

    Correction:

    “That pressure can be calculated as M/g(effective)…” should be
    “That pressure can be calculated as M g(effective)…”
    The interesting result is that a constant surface pressure will be produced by less mass per unit area at the poles compared to the equator.

    To Stephen: OK but what is causing the solar activity to change?

  15. Stephen Wilde says:

    “To Stephen: OK but what is causing the solar activity to change?”

    Changes in the mix of particles and wavelengths (especially EUV) appear to have an effect on the vertical temperature profile of the whole atmosphere especially at the poles which has an effect on tropopause height.

    A cooling stratosphere pulls the tropopause up and a warming stratosphere pushes it down.

    Those changes then being superimposed on the shorter term variations.

    There isn’t so much effect over a single solar cycle but if one has successive active or successive inactive cycles the effects become more pronounced as time passes.

  16. Ulric Lyons says:

    “OK but what is causing the solar activity to change?”

    Angular relationships of the Superior and Inferior planets with respect to the Sun. The completely dominant metric is the solar wind speed. It has a near daily effect on the AO/NAO, and a high degree of deterministic forecasts can be (and have been regularly) made at such scales at very long range purely from astronomical analysis.

  17. Doug Proctor says:

    Stephen Wilde says:
    December 12, 2012 at 9:22 am
    It’s all coming together isn’t it?

    Whether meant in a larger scale or purely wrt atmospheric processes, a good observation. All the controversy of CAGW has initiated a groundswell of thought and community discussion on what has always been an expert, reductionist subject. How else to explain the apparent intense, serious work by smart people that comes to diametric positions from mostly the same data?

    I just had a thought: are we not seeing in science with CAGW what has occurred economically and politically for the West over the prior two centuries, and in now attempting to occur in the non-West? You can either call it the democratization of science, or the development of a “middle class” of science: where before there were the rich/rulers and the poor/ruled, a segment of society becomes more rich than poor, more self-ruling than ruled? Previously, to get away from analogy, there were the educated “scientist” experts and the rest of us who listened to and followed what these fellows in lab coats said. We drank the koolaid. Now we are asking to audit the data, question the assumptions, plot it out ourselves, and have our objections answered.

    Some pro-AGW site I visited described in an amazed and outraged tone how skeptics not only disagreed with the “experts” but actually “tried” to redo the work that had been done. I couldn’t help but be shocked that attempts to replicate results by anyone outside the specific, doctor’d consensus would be a scandal. On reflection, of course, I realized it wasn’t a scandal: it was a sacrilige.

    The rise of the middle-class scientist: this is what Mann, Hansen and Jones hate and fear. The aristocracy of science is threatened every time one of you fellows logs onto Tallbloke’s. Back in the ’80s I was one of those who bought all the Sagan-esque studies of “Nuclear Winter”, reading, reading and then quoting without thinking much. Of course it was for a good cause, getting nuclear weaponry reduced. But of course it didn’t make sense outside of the modeling (though it did make good movie-making narratives).

    If/when the skeptical side and nature debunks CAGW, there will be a nuclear chill on the self-importance of scientists. Back in the late ’20s when Bernard Russel, H.G. Wells and others felt that only scientists could be trusted to run the world (as they were dispassionate advocates of truth, justice and the Western Way), it seemed reasonable. Since then we have had thalidomide, indiscriminate use of pesticides and herbicides, Three Mile Island and – now – CAGW. And all the good stuff of medicine and micro-technology, all coming from scientific endeavours. Which just shows how scientists are like everybody else, nobless oblige mixed in with ego-maniacal self-interest.

    It has been often said that the best thing a university education does is teach you how to teach yourself. CAGW and its proponents demonstrate how necessary that skill is among the general population. Aristocratic institutions benefit themselves and are strong through the weakness of the others. The rise of the middle-class scientist, like the rise of the middle-class political-economic, could well be the unintended result of the internet. No wonder the powerful want it suppressed! No wonder Mann et al want their data to be held confidential! Every time the powerful exert their power they do it best when they can control what others know. When you can’t “spin” something, your options are limited.

    These thoughts went off topic, but have been provoked by not just Smith’s article, but by everyone’s comments on his article (and so many others at this site). With a readership prepared to do what the MSM journalists used to do – examine, consider, verify, refute, generally dig into what lead to what we are being told – is it as likely that we will be blindsided by the actual results of what we have been so wisely told to do?

  18. michael hart says:

    Doug, interesting. A couple of additional remarks:

    1) Large computing projects can have a life of their own, just like other large projects. Imagine if Stephen Wilde posted a hard-disk to Phil Jones with the message “Here is a plug-and-play module, compatible with your ‘lifetime’s-work’ program that will help you model the atmosphere better”, based on what he describes above. If it was a finished product the better part of me actually believes Phil Jones would try to find some CPU time to run it. But, for many other reasons, that can’t happen. So the current paradigm remains in the box-seat. Technological “lock-in”.

    2) Many lay people might be shocked by the limitations of peer-review. Prestigious Journals do publish papers that contain truly awful mistakes. I recall one Professor defending the honour of a (supposedly anonymous) reviewer in such circumstances with “That is a question a reviewer just can’t ask.” People such as Michael Mann dislike others such as Steve McIntyre because he DID ask forbidden questions.
    And it can be difficult to forgive someone for being right. :)

  19. P.G. Sharrow says:

    @Doug Proctor says:December 12, 2012 at 5:24 pm

    Good observation Doug;
    There is an old Hopi Indian prophesy “The new age will begin when a net covers the world”

    The internet allows every sentient being on the planet to communicate, no longer can the Elite control the flow of information and knowledge. The democratization of science is the result of this. The priest class is being exposed to scrutiny of everyone and even an old dirt farmer can have his say. We Don’t Need Them to examine and explain how the universe works. We can see and discuss it among ourselves. Not all the uneducated mass are too dull to understand as not all the educated are brilliant thinkers. The age of Ruling Elite is ending, WE DON”T NEED THEM. pg

  20. suricat says:

    TB.

    Thanks for the ‘heads up’ at Chiefio’s. I see that ‘Earth spin’ still makes the Chief’s head spin.

    IMHO we really need a posting somewhere that explains the Earth centrifuge phenomenon which leads to a ‘three cell circulation’ in each hemisphere and explains the Coriolis Effect that not only leads to the ‘Trade Winds’ at the ‘boundary layer’, but also explains the high speed latitudinal winds at the tropopause which makes the Chief’s head spin. :)

    However, he has, partly, explained the ineffectual property of ‘radiative energy transfer’ within the tropo and ‘hinted’ on the altitude of Earth’s ave. radiation sig.. Good re-posting Rog. :)

    Best regards, Ray.

  21. tchannon says:

    Leroux. Either large books or in French.
    “His studies started by being cantered on his homeland, Africa, were he struggled to explain meterologic phenomena (as the Sahel droughts) with classic theory. By carefully examining satellite imagery he understood that the tri-cellular model was invalidated by the meridional movements described by large masses of cold air coming from the poles.”

    Part of what he is saying is the Synoptic obsession which has existed from maybe 1910 took the eye off the opposite view although this existed earlier.

    He is also to the point of savage, displeased with the AGW mob, yet he ended emeriti. Unfortunately the Anglo- and Francophone worlds still do not meet.

    A starting point

    http://www.eurotrib.com/story/2008/8/14/64552/3547

  22. E.M.Smith says:

    @Hans:

    I used the metaphor “polar blobs” just because most folks don’t know Leroux. I think he is right.

    http://chiefio.wordpress.com/2012/09/29/marcel-leroux-wikipedia/

    Just didn’t want to take on that battle in the middle of getting the tropopause right, so talk about it “obliquely”. I also don’t see it as antithetical to Hadley Cells et. al. It is more the case that it whacks into the cells and changes where they are and what is happening. Basically, makes all the interesting weather in between Texas and The Arctic ;-)

    But go to, say, Brazil, and we’re in the land of Hadley Cells and not much in the way of Mobil Polar Highs nor “polar blobs”… So I can’t see throwing out one as necessary for embracing the other.

    Per The Blobs and ‘loopy jet stream’ and what it all meant: I’m trying to both be true to the science, and yet be accessible to folks who don’t know the jargon. The average person who maybe watches the nightly news / weather. In technical terms, I’m saying that the Cold Phase PDO has deeper Rossby Waves in the Jet Stream, that causes more poleward extensions of warm meridional air and more equatorward extensions of polar cold air (your ‘slower leakage’) and then make reference to the MPH as those “blobs of arctic air”.

    At the end of a warm period, we get zonal jet stream flow and fewer MPH. During a cold phase, meridional Jet Stream, more MPH, and a stronger Polar Vortex. All enhancing heat flow out until such time as things cool down enough to remove the heat low pressures. Then the cycle repeats. (likely triggered by solar / lunar-tidal modulations).

    But hard to say that and stay “approachable” to the car mechanic who watches nightly news…

    The reason NOT to use “tropoSphere rules” (and I considered it) has more to do with the AGW “spin” on things than with “what makes weather” (or 30 year average called climate…) Since the IPCC / AGW Crowd are concentrated on warming via ‘back radiation’ and that involves a Top Of Toposphere vs Stratosphere dynamic. So to address that, one needs to take on the TropoPause directly. That’s the place where the ‘showdown’ between convection / condensation / clouds vs Stratosphere takes place. For weather, yes, Troposphere rules… For IR radiation arguments, not so much…

    @Max: Cute! I like it ;-)

    @Doug Proctor:

    Yes, we’ve not only invaded their “Church” and said we don’t need to take the sacrament of communion to be “good with God”, but we’ve demanded to read the Bible for ourselves. Heck, some of us are even translating that sucker out of Latin and questioning Papal Infallibility… The Popes and Cardinals don’t like that one bit…

    Oh Well… (Pardon me while I get some nails to pound this doctrinal critique to the church door…)

    IMHO it is a necessary function of a free society. A “Self Organizing System” ( SOS? Hmmm…) As long as “Joe Blow” thinks the “Experts” have been doing OK, we’re happy to leave it to them. Once we get a whiff that they are not doing their job, and are instead indulging in (indulgences?…) feather bedding and deception, well, we “self organize” into an alternative structure to “get the job done”.

    This drives “Central Control” freaks nuts, so they try to prevent it at every turn. (What? You thought licensing and regulation were for YOUR benefit?…) But in the end “You can’t stop the signal, Mal.” (from a movie…)

    I call it a “Community Barn Raising”. It’s just what people do. Be it barn, or “Climate Science”, or The Reformation, or even just the internet bypassing BOTH censorship and a biased media not doing their job.

    “I am FOIA-2011″…

    “I am Monkton”…

    @Michael Hart:

    Organization end up with a lot of ‘informal rules’. We, the unwashed, care not for them… We’re the lynch mob in their eyes. A Bad Thing most of the time… but when the Judge is letting his Brother off for murder and his cousin the D.A. is not going to ask that embarrassing question due to being in bed with the Judges Wife… well, sometimes somebody has to bring a rope…

    At least, that’s how I think THEY see us…

    @Suricat:

    Neither the rotation of the earth, nor the Coriolis effect makes my “head spin”. Not even a tiny little bit.

    Look, the article is already too long for the “average joe”. If I go making a 4-D model out of it, I’ll lose all audience. (don’t forget time is a dimension).

    If you can point at a global, 3 D animation (thus 4-D) of the globe showing ALL air flows, I’ll gladly add the link ot the article.

    BTW, the whole POINT of the article is to address the radiative “boundary” at the tropopause and show that it isn’t.

    I don’t see where riding the hobby horse of MPH, nor that of Corriolis causing trade winds, is going to improve things for that purpose. Generally, when I’ve tried that on folks in discussions, they start to glaze…

    So yes, I’ve made it a 2 D easy to approach model for “purposes of illustration” of just how much it doesn’t matter how much CO2 is in the troposphere. Hopefully that doesn’t make YOUR head spin too much…

    @All:

    Please bear in mind that to illustrate one thing, you must remove others. That does not mean you do not understand them, nor does it mean you don’t LIKE them. It means they are in the way of the audience.

    Sometimes that means “picking your battles” and using the common metaphor or jargon, even though you think it wrong. “Greenhouse Gas” is just SOOO wrong. The trophosphere has no lid and there is no prevention of convection nor condensation. So you want to fight THAT particular battle in every single place it is used every single time you want to say something? Really?

    So you “pick your battles”. Every so often I’ll “talk dirt” about the idea of GHGs. Every so often I’ll mention MPH. (Usually in the form of a non-political ‘polar blob’… ;-) But if you want to fight a battle about the tropopause being “not a pause” and the troposphere being “not a sphere”, and the “barrier” being “not a barrier” but instead characterized by mass flow and turbulent edges… well, that’s not the time to fight 3 other battles too and force feed something to the observer that will cause them to gag…

    My bias is that I think Leroux is right part of the time and the ’3 cells model’ is right part of the time. The latter has a clean conceptual picture that works for short periods of time, in some geographies, and gets across the idea of convective zones rather well. The former covers the bigger events (like the common Canada Express…) that runs a bulldozer through the 3 Cell structure and makes most of the interesting weather. It’s an oscillation layered on top of, and disruptive to, the banded model.

    But it would take a half dozen pages just to get THAT set of ideas “out there”. Which would prevent the rest of the article being read, or effective.

    (Or put another way, do you start every discussion of IR with a brief dissertation on Quantum Mechanics vs General Relativity and why they are wrong?)

    So please, just because someone uses a 3 cell picture to illustrate that the tropoSphere isn’t a sphere and that the tropoPause isn’t paused and is a complex topology, please don’t assume they are anti-Leroux.

    When I was a kid, my local weather news would talk about “Polar Air Masses” moving down from Canada. They are part of the fundamental building blocks of my understanding of weather… Station was up near Chico, where A. Watts is located. They, then, had maps with the jet stream and H / L areas and wind arrows and everything. Farm Country and the farmers needed to know… Best weather reporting I’ve ever seen. I couldn’t even begin to talk about a Canada Express dropping temps 50 F in one day in Dallas (that I lived through) without the phrase “polar air mass” being used… And you can’t talk about how the storm track that brings ll the rains to California works without understanding trade winds and Coriolis effects. (nor the return path of the hurricanes that hit Hawaii and sometimes ‘hook’ up into Los Angeles and Phoenix).

    In short: Don’t assume that omission is error nor ignorance.

  23. suricat says:

    E M Smith.

    “Neither the rotation of the earth, nor the Coriolis effect makes my “head spin”. Not even a tiny little bit.”

    No, I see you’ve removed the bracketed comments you made which caused me to perpetuate the ‘play on words’ that you started. OK, if this has offended I apologise, but you started it. :)

    Whilst I concur with, just about, all of your post it’s unfinished. What’s an ‘MPH’? Its a ‘Mobile Polar High’! If you want ‘Joe Public’ to be enthused by your postings, I respectfully suggest that you add definition to the components of the objects that you introduce. Following the full introduction of the subject I can’t envisage anyone who’s interest wouldn’t be sharpened. It’s fascinating.

    If you limit your subject to ‘MEP’ (Maximum Entropy Production) from ‘insolation’ (incoming solar radiation) you lose definition of Earth’s reaction because there are other processes in action as this happens.

    How can the strat achieve near surface altitudes during the polar winter? The boundary layer vacates the near surface atmosphere with its planar centrifuge system when the MEP system can’t supply enough higher altitude gasses within the tropo (I call this ‘pump hunt’ and I don’t ask to be excused for this engineering term because that’s exactly what it is :) ).

    How can the Polar Vortex split into two ‘vortices’ (?) in the NH? The boundary layer planar centrifuge is ‘driven’ (impelled) by two continents at ~180 longitudinal degrees apart with opposing separation zones of ‘open water’ (ocean) at ~90 degrees to each continent. With the planar centrifuge strengthened by opposing land masses and weakened by opposing open waters at ~90 degrees it’s understandable that the NH Polar Vortex may be compromised to form two separate ‘vortexes’ (not vortices [this is an inference towards a correct definition for the object/s under discussion]) at times.

    It’s now late/early 19/12/2012, I’m 300 miles from home visiting Mum before Christmas and I apologise for my late response to your post here, but if there’s no activity here before the event, or I’m unable to post, I wish you a happy Christmas and a prosperous New Year Chiefio. :)

    Best regards, Ray.