WUWT commenter Ian Cooper says:
I thought that this site may be of interest to those pondering the warming of the Antarctic Penninsula. I came across this while I was scouring the net to learn more about the Southern Annular Mode (SAM) and it’s influence on our local New Zealand weather/climate. I hadn’t seen this here before, so apologies in advance if someone has already brought this to your attention. I was particularly taken by the second paragraph of this page, which I have copied below.
Due to the southward shift of the storm track, a high SAM index is associated with anomalously dry conditions over southern South America, New Zealand and Tasmania and wet conditions over much of Australia and South Africa. The stronger westerlies above the Southern Ocean also increase the insulation of the Antarctica. As a result, there is less heat exchange between the tropics and the poles, leading to a cooling of the Antarctica and the surrounding seas. However, the Antarctic Peninsula warms due to a western wind anomaly bringing maritime air onto the Peninsula (Fig. 5.9). Indeed, the ocean surrounding the Antarctic Peninsula is in general warmer than the Peninsula itself and stronger westerly winds mean more heat transport onto the Peninsula. Over the ocean, the stronger westerly winds tend to generate stronger eastward currents. Furthermore, the divergence of the currents at the ocean surface around 60oS is enhanced because of a larger wind-induced Ekman transport. This results in a stronger oceanic upwelling there.
From: Universite catholique de Louvain
http://stratus.astr.ucl.ac.be/textbook/chapter5_node6.html
The Southern Annular Mode
The equivalent of the NAM in the Southern Hemisphere is the Southern Annular mode (SAM). Various definitions of SAM have been proposed: a convenient one is the normalised difference in the zonal mean sea-level pressure between 40 oS and 65o S. As expected, the sea level pressure pattern associated with SAM is a nearly annular pattern with a large low pressure anomaly centred on the South Pole and a ring of high pressure anomalies at mid-latitudes (Fig. 5.8). By geostrophy, this leads to an important zonal wind anomaly in a broad band around 55oS with stronger westerlies when SAM index is high.
|
Due to the southward shift of the storm track, a high SAM index is associated with anomalously dry conditions over southern South America, New Zealand and Tasmania and wet conditions over much of Australia and South Africa. The stronger westerlies above the Southern Ocean also increase the insulation of the Antarctica. As a result, there is less heat exchange between the tropics and the poles, leading to a cooling of the Antarctica and the surrounding seas. However, the Antarctic Peninsula warms due to a western wind anomaly bringing maritime air onto the Peninsula (Fig. 5.9). Indeed, the ocean surrounding the Antarctic Peninsula is in general warmer than the Peninsula itself and stronger westerly winds mean more heat transport onto the Peninsula. Over the ocean, the stronger westerly winds tend to generate stronger eastward currents. Furthermore, the divergence of the currents at the ocean surface around 60oS is enhanced because of a larger wind-induced Ekman transport. This results in a stronger oceanic upwelling there.
The majority of the effects of SAM could be explained by its annular form and the related changes in zonal winds. However, the departures from this annular pattern have large consequences for sea ice as they are associated with meriodional exchanges and thus large heat transport. In particular, a low pressure anomaly is generally found in the Amundsen Sea during high SAM-index years (Fig. 5.8). This induces southerly wind anomalies in the Ross Sea (Pacific sector of the Southern Ocean) and thus lower temperatures and a larger sea ice extent there (Fig. 5.9). On the other hand, because of the stronger northerly winds, the area around the Antarctic Peninsula is warmer when SAM index is high, and sea ice concentration is lower there .
|
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
@Rational Debate says:
February 5, 2011 at 12:00 pm
“…Peer review isn’t about deciding which hypotheses or which experiments are or aren’t correct….” I beg to differ. I think that is exactly what Mann and The Climate Thugs intend it to be, as set out in the ClimateGate emails.
The SAM [ “Southern Annular Mode” . Also called the Antarctic Oscillation; AAO ] is almost the only one of the great climate controlling / influencing systems that has been almost totally ignored right through the recent climate argument.
It has significant influences on the only ocean basin, the Great Southern Ocean, that has links to all of the world’s major ocean basins.
Unfortunately nearly all actual infield climate research has ignored the SAM and it’s significant climate influences as the world economic powers from which most of the climate research money originates are all in the northern hemisphere.
So the North Atlantic, the north Pacific and the Pacific equatorial regions receive almost all of the available funds for field research in climate studies.
Yet the SAM is also located where the largest mass of ocean waters and immense globe encompassing current systems are located and those ocean waters and their associated currents drive the climate in so many ways most of which are still at best only partially or barely understood or not yet dreamed of by ocean and climate researchers.
Australia’s climate / weather is controlled by the Pacific factors such as the ENSO / El Nino / La Nina in it’s eastern one third, by the Indian Ocean and the phase of the critical to rainfall in SE Australia, “Indian Ocean Dipole” and finally the SAM phase during the winter across the southern regions of Australia.
A positive SAM means that the high pressures that originate from the Hadley cell circulation that create Australia’s normally dry semi desert conditions in the heart of the Australian Continent [ it’s anything but dry at the moment! ] move south and this shifts the band of low pressures and their associated frontal systems that southern Australia relies almost entirely on for it’s winter rainfall, even further south.
[ Only low to very low rainfall totals occur during our late spring, summer and early autumn period here in SE Australia. ]
So those frontal systems do not penetrate very far up into Australia and the winter rains are much reduced with consequent dry winter conditions, poor rainfall, water shortages and drought occurring and severe crop yield reductions or even complete crop losses as a result.
All of which we have experienced for some 15 years now until this year’s shift in the ENSO, the IOD and now the SAM.
Now we have immense areas , equal to areas greater than all of Germany and a part of France under water, something not seen since the same confluence of these climate phenomena last recorded in the early to mid 1970’s.
A positive SAM has been ongoing for most of the last two decades but it has reverted to a negative phase recently.
The result is that here in SE Australia we are already seeing even the weak summer front and trough systems penetrating further north into the continent bringing increased amounts of tropical origin water vapour down into SE Australia, tropical origin water vapour volumes that are heavily enhanced by the very strong La Nina which has pushed very warm Pacific waters up against Australia’s eastern sea board which then feed into the systems that transport it down into southern Australia.
The IOD just finished was also negative for one of the very few times in the last couple of decades and this brought warm Indian ocean waters up to the NW coast of Australia from where high water vapour volumes also streamed via our North West cloud bands into SE Australia.
It is about the first time since about 1974 that we have experienced a La Nina and a negative IOD together.
Both in 1974 and now 2011 there was and now is very extensive flooding across all of the eastern half of Australia.
A negative phase SAM with the winter rain generating low pressure systems traversing Australia much further north and along our southern coast , a now forecast continuing La Nina and perhaps another negative IOD will mean the strong likelihood of very heavy and extensive flooding in SE Australia during our oncoming southern winter in the next few months.
Argentinean weather /climate researchers do have some research on the SAM and their conclusions on the impact of the SAM phases on Argentina are similar to the impact on Southern Australia.
Perhaps the other question that arises from all these changes in the major climate influences is; Are we seeing right now a quantitative shift in the global climate occurring right across the globe towards a cooler and possible wetter climate phase?
If so, Why?
eadler says:
February 5, 2011 at 5:29 am “This is an aid in understanding of what is driving the temperature record for Antarctica, and explains why the West Antarctic Peninsula is warmer than the rest of the continent. ”
Many commentators seem to underemphasise that the so-called warm Antarctic peninsula is a temporary anomaly. If it was a permanent feature it would not be coloured red. Two possibilities, either the baseline is wrong or the present measurements are genuinely and recently anomalous. Next question, will the various proposed mechanism return the red Peninsula to neutral again, when, and by what mechanism?
Having read what I have, I’d suspect that the historic quality of Peninsula measurement is prone to error and that the baseline is wrong. That’s only an opinion based on the reading of others. The present heat might not be entirely anomalous.
Geochemists like me are far more used to working with anomalous data than with doing the climate thing to level blips down to smoother averages. I’ll give a current example next.
Geochemists investigate anomalies. Example.
Here is a time lapse of wind in the west hemisphere prior to and including the landfall of Queensland’s cyclone Yasi, thanks to several posters including Bill Illis/Bob Tisdale & elsewhere
http://www7320.nrlssc.navy.mil/global_nlom32/navo/WHOSP1_nlomw12930doper.gif
Here is a time lapse for January, with the invitation to look for warm SST as a driver for that cyclone, that was named on 27 Jan 2011 when about 300 km NNE of Port Vila (that is, at about 170E, 15S). The surface sea temperatures don’t look terribly anomalous to me, particularly at the end of the month of January (where my data run out).
http://lwf.ncdc.noaa.gov/teleconnections/enso/indicators/sea-temp-anom.php?begmonth=1&begday=1&begyear=2011&endmonth=1&endday=26&endyear=2011&submitted=Animate+Selection
On the first animation Yasi can be seen as a mass moving from this position about 28 Jan, to move WSW to clobber Innisfail about Feb 3rd. That’s 6 days for 2,500 km of a “bullet” cutting straight through the turmoiled global system of the first animation, over seas described as “warm around eastern Australia and contributing to the strength of the cyclone”. Bunkum. If this is as good as the climate people can do, it’s not very good.
bubbagyro says:
February 5, 2011 at 3:31 pm
“I don’t have time for each mistake you have cited, it would take a while.
Two quickies:
1) The sea ice extent, takes into account these itemized losses you cite, of course, or else the report could not say extent, now, could it?”
I know the EXTENT takes into account the loss of the land-locked ice shelves, I said the areas refreeze with sea ice in the cold season restoring the extent of the ice.
But NOT its thickness. Or its ability to slow the flow of the glaciers on the land those shelves previously blocked.
“2) For ice shelves “to break off” as you mention, they have to grow past the cantilever support strength. If they “melt” then they recede and do not break. Breaking off is an admission that they had grown to that point. This has been dwelt upon in recent WUWT postings. Melting is very, very difficult at average -20°C air temp, at any rate.”
There are several mechanisms that result in loss of ice, melting from sun and rain on the peninsula occurs; a -20degC average does not preclude warmer days. But the warmer ocean under the ice is also a factor and the rise also increases the chances of the cantilever support failing without any growth of the ice shelf.
post by; JimF says: February 5, 2011 at 7:25 pm
I’d laugh, because your comment is oh so true wrt climategate & that crew, if the entire ‘climate’ situation weren’t so bloody disgusting and anti-science. It’s gotta be ‘post normal peer review’ for those guys apparently.
Jim Steele, Feb 5th at 11.12a.m.
The “Foehn,” or “Fohn,” winds as they are often spelt here in N.Z., are well known to New Zealanders by the more colloquial name of the “Nor’ Wester!” People on the east coast of both major islands can experience their highest summer temperatures during a spell from the Nor’ Wester. Today was one of those days. Timaru (airport) about 100 miles (160 km’s) south of Christchurch recorded a T-max of 40C. The temperature is expected to drop there by 20C tomorrow.
The humid air affecting the west coast of both major islands at the moment can be directly linked back to the trailing outfall of moist air from the remnant of TC Yasi. This trailing southern edge has also caused major flooding in Melbourne over 1,000 miles away today, such is the size of Yasi’s influence. The rising Nor’ Wester that precedes the approaching front that connects back to Yasi, leaves its’ moisture on the west coast before descending down the main divides (the Southern Alps in the South Island) resulting in hotter, drier air spreading out across the plains. This is the traditonal peak of N.Z. temparatures. New Zealand’s official highest temperature was set at Rangiora, just NW of Christchurch, on Feb 7th, 1973. The temperature was 41.2C. Although the Antarctic Penninsula sits at a far greater latitude than N.Z. it wouldn’t be a stretch to see similar effects on the Penninsula with its’ north-south spinal range.
Rom Feb 5th at 8.58 p.m.
I concur with your comments about SAM being almost forgotten amongst the leading protagonists connection with their main NH influences such as the PDO, AMO etc, not to mention the obvious influence of the equatorial elements that make up ENSO.
I first heard of SAM through the NIWA website, but they don’t go into sufficient detail to satisfy my curiosity. Your further comments on the total influences on the Australian climate were not only succinct, but very enlightening on features pertaining to N.Z. weather and climate as well. The Great Southern Ocean and the South South-Pacific should not be understimated by anyone pondering global climate regimes. Just look at the latest Full Global SST Anomaly chart
http://www.osdpd.noaa.gov/data/sst/anomaly/2011/anomnight.2.3.2011.gif
We always check out what is happening along the equatorial line, in this case a typically strong La Nina signature, but what about the large area of above average SST water just below the blue of the La Nina. People have talked for some time recently about the above average temperature of the water near NE Australia. I wonder though about the impact of the obviously warmer water further east. I have noticed through much of our S.H. summer how highs that move into the latter zone become stationary, and influence the paths of tropical depressions and cyclones as they move east, either onto Queensland, or NEastern N.Z. as occurred on the previous two weekends here, with similar effects, but at different scales. The S.H. anti-cyclones (highs) spinning counter-clockwise appear to act as a cog churning tropical moisture bombs in an easterly direction to cause havoc where they might fall.
Our cyclone season has a full two months to go, and possibly more during a big La Nina event, so who knows what may befall us yet. They come and go with such rapidity it is hard to be more fully prepared for them (TC’s) than we are at the moment.
The influence of SAM amongst all of this is something that is going to consume my time immeasureably, but it will be enjoyable learning more about the complex nature of the nature we live in.
Cheers
Coops
@- maksimovich says:
February 5, 2011 at 3:27 pm
“As there are a number of problems with the resolution of statospheric chemistry in GCM and understanding in the IPCC ar4 the current ozone assessment (wmo2010 ) was asked to resolve the issue by the parties to the MP.
EG chapter 4
Observations and model simulations show that the Antarctic ozone hole caused much of the observed southward shift of the Southern Hemisphere middle latitude jet in the troposphere during summer since 1980. …”
Thank you for the quote from the wmo2010 assessment, it supports my position that the SAM is driven by the temperature differential between the troposphere and stratosphere around the pole.
As the troposphere gets warmer, or the stratosphere cools the SAM will intensify/move south.
It does seem that the main cause in the intensification of the SAM is the stratospheric cooling due to changes in ozone. Changes caused by CFCs. A prime example of how very small changes in the percentage of a rare component of the atmosphere can have significant effects of the energy flows into and out of the biosphere.
The ozone loss is exacerbated by the cooling stratosphere because the action of CFC’s in destroying ozone is enhanced if the stratosphere cools and forms ice crystals as a reaction substrate.
The role of solar UV is crucial, the depletion of ozone from CFCs is a photochemical reaction, which is why the ozone hole appears when sunlight returns to the polar stratosphere when an increase might be the expected result. So the level of solar UV drives the rate of generation/depletion of ozone which in turn affects the temperature differential of the troposphere and stratosphere at the pole and drives the SAM.
But I don’t think that you can ascribe the changes in ozone, the hole and the subsequent intensification of the SAM to solar UV changes, it requires the role of CFCs and the effect of CO2 on the differential warming troposphere/cooling stratosphere to explain the changes.
Further to comments above, check out this satellite image of New Zealand this afternoon (2.06 U.T.C.) showing the building front at the bottom of the picture.
http://satellite.landcareresearch.co.nz/noaa/?history=qd06021.txt
The cloud build-up on the western side of the South Island, as well as the Lower North Island (L.N.I.), with some cloud spilling through Cook Strait that divides the two major Islands, is typical for the early stages of an approaching cold front at these latitudes. I am buried under that L.N.I. cloud bank and all of its’ associated humidity.
Timaru sits in the clear on the smooth section of the South Island east coast between the leading edge of the front, and the patch of streaky, pink/red cloud sitting over Banks Peninsula, where Christchurch resides. Some of the typical white streaks of lenticularis, or Nor’ West Arches as they are known here, are starting to form ahead of the front, and in the lee of the Southern Alps further north. A Nor’ Wester, or Fohn wind in action.
ahhhhhhhhhhh, reading this is better than doing the crossword or Sudoku or… anything. There are so many fine lines weaving together here, though
I’m really puzzled by the Southern Annular Mode pictures above. They seem to be completely at odds with a key factor in Erl Happ’s recent post here. His Figure 2 shows a pretty constant UNIQUE LOW in atmospheric pressure at around 60 degrees South, rising to both the South and North of this ring-latitude. Precisely on this hangs his explanation for the constantly high winds here – which makes sense. Yet in the pictures above, there is primarily a steady lowering of pressure as one approaches the South Pole – ish.
Or have I been really thick and misunderstood it all?
I love this. It’s like the Earth and solar system are a whole orchestra and all the players affect each other, solar / barycentre / electric / magnetic oscillations > high atmospheric events > lower atmospheric oscillations > ocean oscillations > land temperatures. Oh, and we also have mysterious effects too, on everything – but that could spiral OT so no more said.
Izen said:
“As the troposphere gets warmer, or the stratosphere cools the SAM will intensify/move south.”
Exactly as I have been saying. The trouble is that the stratosphere cooled when the sun was more active and is now warming a bit with the sun less active.
Thus you have to say this:
“But I don’t think that you can ascribe the changes in ozone, the hole and the subsequent intensification of the SAM to solar UV changes, it requires the role of CFCs and the effect of CO2 on the differential warming troposphere/cooling stratosphere to explain the changes.”
But that is where I say that the consensus has got it wrong.
It all happened before in the MWP and presumably in the Roman Warm Period and all previous warm periods without any human intervention from CO2 or CFCs. The jets went way poleward in the MWP too so the stratosphere must have cooled then too when the sun was more active.
So a cooling stratosphere with an active sun and a warming stratosphere with a less active sun just has to be the natural order of things and if we have affected it at all then our contribution is probably too small to measure.
If the natural order of things were for the stratosphere to warm with a more active sun (as always assumed) then that would have pushed the jets equatorward during the MWP but that did not happen.
@-Stephen Wilde says:
February 6, 2011 at 5:48 am
“It all happened before in the MWP and presumably in the Roman Warm Period and all previous warm periods without any human intervention from CO2 or CFCs. The jets went way poleward in the MWP too so the stratosphere must have cooled then too when the sun was more active.”
I defer to your apparent comprehensive knowledge of the intensity and position of the SAM during the MWP and the differential temperature of the troposphere/stratosphere at that time.
Perhaps you can provide the source of this information?
My thanks to those who have put me right on the practice and intent of the peer review process.
However, whilst I see the benefits of using blogs for peer review, I feel uncomfortable because of the uncontrolled ability of the blog owner to influence the process (Willis Eschenbach gives a prime example here https://public.me.com/ix/williseschenbach/Svalbard.pdf – in this case the blog owner and the authors are essentially part of the same team but this would not always be the case).
Izen asked:
“I defer to your apparent comprehensive knowledge of the intensity and position of the SAM during the MWP and the differential temperature of the troposphere/stratosphere at that time.
Perhaps you can provide the source of this information?”
Well you accepted that if the stratosphere cools then the jets shift poleward. That clearly happened in the northern hemisphere MWP when the sun was more active as evidenced by Viking Settlements in Greenland and a warm Europe.
So I’ve made the imaginative leap that if the cause of the cooling stratosphere is solar (as it must be because the stratosphere is now warming with a less active sun after a pereiod of cooling with a more active sun) then there is likely to be a similar effect at both poles.
Now currently with the quieter sun we are seeing greater jetstream meridionality in both hemispheres but not identical patterns because the Antarctic is a continent surrounded by oceans whereas the Arctic is an ocean surrounded by continents. That increased meridionality in both hemispheres at the same time supports my conjecture as does the decreased meridionality in both hemispheres during the late 20th century.
So the burden of proof is with you to state why the two hemispheres should NOT be affected similarly by a variation in solar activity.
Lucy Skywalker,
Note the “anomaly” view: “[…] a large low pressure anomaly centred on the South Pole and a ring of high pressure anomalies at mid-latitudes […]”
Erl’s plot is in absolutes.
It is precisely the mainstream convention of relying too heavily on anomalies that has mired both the public & climate science in the pit of Simpson’s Paradox. See my comment here [ http://wattsupwiththat.com/2011/02/04/noaa-enso-expert-odds-for-a-two-year-la-nina-event-remain-well-above-50/#comment-592404 ] where I clarify that the annual cycle is nonstationary. The mainstream is so caught up in the first moment (the mean) that they don’t notice the second one (variance). It certainly doesn’t help that they don’t differentiate between grain & extent (if they are aware of extent at all!)
Hello Paul,
There is a lot that I like in that Leroux paper. I haven’t seen it before.
He is confirming much of my proposition as regards the top down polar side of things but doesn’t much go into causation.
Although I’ve chosen the level of solar activity as the dominating top down driver (via chemical not radiative processes) that still leaves room for other features of solar behaviour to be relevant such as Length of Day and solar cycle length.
The chemical nature of the relevant processes also allows for magnetic field effects since part of the chemistry is a consequence of atmospheric interactions with charged particles coming in along the magnetic field lines.
Another advantage of nailing atmospheric chemistry as the primary process is that it breaks the impasse with Leif Svalgaard et al who concentrate entirely on radiative processes.
What we have here is atmospheric chemistry changing in response to changes in the mix of wavelengths and particles from the sun so as to change the energy content of atmospheric layers differentially, alter the heights at each boundary layer and redistribute the tropospheric air circulation with the most pronounced effect on those mobile polar highs that Leroux describes.
Furthermore the uv effect on the stratosphere below 45km seems not to be the major player in determining the energy content of stratosphere and mesosphere. Instead the ebb and flow of the solar induced ozone destruction processes above 45km seems to dominate the vertical temperature profile.
The resulting change in cloudiness and albedo as the jets wave about more meridionally changes solar input to the oceans to change the global energy budget from positive to negative and back again depending on the degree of meridionality/zonality.
Paul Vaughan
Stephen Wilde
Re: LOD
For some time now I’ve been suggesting that LOD is connected to kind of magnetic brake within Earth’s interior. The top ‘geomagnetic’ man Andy Jackson appears to tink on same lines:
http://www.agu.org/meetings/fm10/lectures/lecture_videos/GP43C.shtml
@-Stephen Wilde says:
February 6, 2011 at 10:15 am
“Well you accepted that if the stratosphere cools then the jets shift poleward. That clearly happened in the northern hemisphere MWP when the sun was more active as evidenced by Viking Settlements in Greenland and a warm Europe.”
When the temperature differential between the stratosphere and the troposphere affects the SOUTH polar vortex which intensifies and the jets shift pole-ward. But other factors can alter jetstream positions, ENSO is one. And as you acknowledge later the Northern anular mode is less well defined/stable as a result of geography. I don’t think it is ‘clear’ what was happening to stratospheric temperatures or any North polar vortex and asociated jets during the MWP in Northern Europe.
The assumption you make about a more active sun is not supported by Vikings in Greenland, their occupation started AFTER the peak of the N hemisphere MWP when temperatures were lower than the present. BE-10 isotope levels indicate that solar activity was no greater than at present.
“So I’ve made the imaginative leap that if the cause of the cooling stratosphere is solar (as it must be because the stratosphere is now warming with a less active sun after a pereiod of cooling with a more active sun) then there is likely to be a similar effect at both poles.”
Imaginative leaps are best made after considering every other possibility. Present changes in temperature of the stratosphere are also caused by the decreased warming from decreased ozone and increased cooling by increased CO2
Warming due to increased solar input also warms the stratosphere more than the troposphere decreasing the differential unlike a GHG forcing which cools it.
“So the burden of proof is with you to state why the two hemispheres should NOT be affected similarly by a variation in solar activity.”
They may well be, but that pre-supposes there are changes in solar activity with sufficient magnitude to cause an observable variation. The difference between the MWP and LIA solar activity was smaller than the ~11 year solar cycle. What magnitude of change does that cause in the present stratospheric temperatures?
There is also a well established climate see-saw effect that shows warming first in the S hemisphere with cooling in the N. hemisphere followed by cooling in the south with warming in the north. Several examples of this occurr shortly after the warming from the last glacial period.Past warming in one hemisphere does not imply that the increase was global.
I asked for the source of the information you had on the SAM in the MWP period because AFAIK there is no data with that local or temporal resolution available that can provide that data.
As I suspected it was not data so much as imaginative leaps, which might be better characterized as ‘jumping to conclusions’?
Varimax-rotated EOF or VEOF (vastly superior to plain EOF for most purposes) suggests the 4 major (statistical) modes of interannual terrestrial climate variability are:
1) SAM (Southern Annular Mode)
2) SOI (Southern Oscillation Index)
3) NAM (Northern Annular Mode)
4) NPI (North Pacific Index)
See Figure 3 & Table 3 here:
Trenberth, K.E.; Stepaniak, D.P.; & Smith, L. (2005). Interannual variability of patterns of atmospheric mass distribution. Journal of Climate 18, 2812-2825.
http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/massEteleconnJC.pdf
Complex (nonlinear) data exploration clearly reveals a lack of independence between these modes, but the insights of Trenberth, Stepaniak, & Smith (2005) are of classic value nonetheless.
Important:
A recurring misunderstanding demands clarification:
LOD does not drive climate; climate drives LOD.
Vukcevic, I suggest that you review the work of N.S. Sidorenkov on multidecadal LOD variations. (I also suggest that you come clean with definitions for “NAP”, etc. People are busy and life is finite.)
Stephen Wilde, I am curious to hear at some point in time (as the weeks & months unfold) which researchers have most influenced your noticeably sharpened focus over the past few months. Your presentation will be further strengthened (dramatically) if you work seasonal variations into your exposition – (i.e. no need to fall into the pit of Simpson’s Paradox with mainstream climate science, awaiting rescue by earth orientation parameter experts…)
Also, when asked for data, just point people at AAM & LOD — truly global (& spatially unbiased) variables, which is why they show with crystal clarity the mark of solar variability …and to be clear for the resident distortion artists: NOT TSI & “irradiance”. Moderators, a serious suggestion: It’s time to consider cracking down on the obfuscatory tactic of DELIBERATELY (& erroneously) conflating insolation with irradiance. Sensible peoples’ time is too valuable to be spent dealing with such hyperpartisan nonsense – or plain naive ignorance in some cases perhaps.
Finally Stephen, I caution you to not fall into the trap of assuming a 1 to 1 relation between solar variation and terrestrial circulation/insolation changes. Clarification: As I have shown, the relationship is with the variance, not the mean. Everyone needs to slow down for long enough to try to contemplatively understand the implications of this, even if they are not experts on the dependency of spatiotemporal summaries on harmonics, grain, & extent. It is important to bear in mind the role of QBO at interannual timescales. I look forward to any efforts you might make to incorporate Leroux’s (1993) Figure 8 into your narrative.
For those familiar with Stephen Wilde’s most common theme over recent months, see if Leroux’s (1993) figures 11 & 13 condense thousands of words into 2 pictures.
Leroux, Marcel (1993). The Mobile Polar High: a new concept explaining present mechanisms of meridional air-mass and energy exchanges and global propagation of palaeoclimatic changes. Global and Planetary Change 7, 69-93.
http://ddata.over-blog.com/xxxyyy/2/32/25/79/Leroux-Global-and-Planetary-Change-1993.pdf
Note that those 2 figures (11 & 13) are “annual” generalizations. Things get a whole lot more interesting when seasonal variations are studied (figure 8 – and AAM & LOD… http://wattsupwiththat.com/2010/12/23/confirmation-of-solar-forcing-of-the-semi-annual-variation-of-length-of-day/ , keeping in mind that annual grain power is inversely related to semi-annual grain variation at decadal extent).
All the Best.
izen says:
February 6, 2011 at 1:13 am
But I don’t think that you can ascribe the changes in ozone, the hole and the subsequent intensification of the SAM to solar UV changes, it requires the role of CFCs and the effect of CO2 on the differential warming troposphere/cooling stratosphere to explain the changes.
Agreed mostly,however we can exclude co2 as the signal is trivial in the stratosphere and is not observable ie it is obscured by other variables wmo 2010.
Secondly GCR is a significant variable that needs to be included as it effects the photochemistry of the stratosphere by production of odd species such as NOx .
We can see the levels of atmospheric attenuation here at high latitude stations Murmansk in the NH in the top and Mirny in the SH bottom.
http://i255.photobucket.com/albums/hh133/mataraka/gcratmosphericflux.jpg
It is only by including the correct differences in externalities eg monthly and annular solar modes, and the annular modes such as SAM and NAM can we start to understand the stratosphere correctly and its effects on the lower atmosphere.
Hi Paul
I might start with PDO-ENSO driver, it is a bit simpler; Pacific is far more self contained than Atlantic.
http://www.vukcevic.talktalk.net/PDO3.gif
Any idea for the pre 1950 ENSO monthly or annual data file ?
just a small correction to my earlier post of Feb 6th at 1.09 a.m.
The official highest New Zealand temperature set at Rangiora on the east coast of the South Island on Feb 7th, 1973, was actually 42.4C, and not 41.2C as I had posted. This record still stands after 38 years.
Rangiora’s record surpassed by a whopping 3.8C the previous N.Z. record set further south at Ashburton on January 19th, 1956. From the only source that I have, a soft covered book titled, “The New Zealand Weather Book,” (published in 1978), I see that yesterday’s synoptic chart was almost identical to the one in that book showing the situation 38 years ago! Hence it is no surprise to see a serious challenge to the long standing record.
Paul, thanks for the constructive comments. I’ll give them thought and see if they can help to clarify my narrative.
Mind you, I see the background climate changes from say MWP to LIA to date as being longer term variations over and above seasonal variability.
I agree that there is no simple 1:1 relationship between any of the components of the system which is why it is hard to see the wood for the trees. At any given moment there are a host of confounding factors at work plus natural internal system chaotic variability. That is why it is not possible to provide nice neat correlations for doubters such as Bob Tisdale. However over longer periods of time the underlying mechanisms do seem to me to be becoming apparent beyond the short term chaos.
One certainly needs to move away from purely radiative physics. The ozone chemistry of the region above 45km seems to be critical and so far poorly understood.
izen said:
“Present changes in temperature of the stratosphere are also caused by the decreased warming from decreased ozone and increased cooling by increased CO2”
On that basis the stratosphere should still be cooling but it isn’t:
http://www.jstage.jst.go.jp/article/sola/5/0/53/_pdf
“The evidence for the cooling trend in the stratosphere may need to be revisited.
This study presents evidence that the stratosphere has been slightly warming
since 1996.”
So the whole basis for your contribution here is ill founded.
Paul Vaughan says: February 6, 2011 at 9:19 pm
I also suggest that you come clean with definitions for “NAP”, etc. People are busy and life is finite.
If NAP- CET correlation is meaningful
http://www.vukcevic.talktalk.net/CDr.htm
(I think unlikely to be coincidence, since the mechanism should be strait forward) than whole of the Arctic / North Atlantic relationship will be far clearer.
The NAP- SSN correlation (specially 1870-present with good SSN record) is a bit of a ‘Pandora box’.
There are personal reasons why I will not make public ‘NAP ideas’ before mid June.
I got now on line little project, I did it in the depth of the UK’s December freeze-up:
http://hal.archives-ouvertes.fr/docs/00/56/34/77/PDF/SSW.pdf
it is just an exercise in writing a reasonably well structured project; have to add more on Antarctica’s case, managed to resolved that too.