I liked this part:
According to the study an important issue remains as to why the poleward expansion is largest in autumn, and there is still uncertainty about the role of external forcings – such as greenhouse gases – as climate models underestimate the southward expansion of the Hadley cell edge.
From CSIRO Australia
Southern Hemisphere becoming drier
A decline in April-May rainfall over south-east Australia is associated with a southward expansion of the subtropical dry-zone according to research published today in Scientific Reports, a primary research journal from the publishers of Nature.
CSIRO scientists Wenju Cai, Tim Cowan and Marcus Thatcher explored why autumn rainfall has been in decline across south-eastern Australia since the 1970s, a period that included the devastating Millennium drought from 1997-2009.
Previous research into what has been driving the decline in autumn rainfall across regions like southern Australia has pointed the finger at a southward shift in the storm tracks and weather systems during the late 20th century. However, the extent to which these regional rainfall reductions are attributable to the poleward expansion of the subtropical dry-zone has not been clarified before now.
Mr Cowan said rainfall patterns in the subtropics are known to be influenced by the Hadley cell, the large-scale atmospheric circulation that transports heat from the tropics to the sub-tropics.
“There has been a southward expansion of the edge of the Hadley cell – also called subtropical dry-zone – over the past 30 years, with the strongest expansion occurring in mid-late autumn, or April to May, ranging from 200 to 400 kilometres,” Mr Cowan said. The CSIRO researchers found that the autumn southward expansion of the subtropical dry-zone is greatest over south-eastern Australia, and to a lesser extent, over the Southern Ocean to the south of Africa.
“The Hadley cell is comprised of a number of individual branches, so the impact of a southward shift of the subtropical dry-zone on rainfall is not the same across the different semi-arid regions of the Southern Hemisphere,” says CSIRO’s Dr Wenju Cai.
The researchers tested the hypothesis that the dry-zone expansion would give rise to a southward shift in the average rainfall during April and May, and questioned how rainfall across semi-arid regions, including southern-coastal Chile and southern Africa, would be affected.
“During April and May, when the dry-zone expansion is strong, rainfall over south-eastern Africa, south-eastern Australia and southern-coastal Chile is higher than over regions immediately to their north,” Dr Cai said.
Using high-quality observations and an atmospheric model the CSIRO team found that for south-eastern Australia, up to 85% of recent rainfall reduction can be accounted for by replacing south-eastern Australia rainfall with rainfall 400km to the north. Such a southward shift of rainfall can explain only a small portion of the southern Africa rainfall trend, but none of the autumn drying observed over southern Chile.
“For south-east Australia, autumn is an important wetting season,” Dr Cai explained. “Good autumn rainfall wets the soil and effectively allows for vital runoff from follow-on winter and spring rain to flow into catchments.”
According to the study an important issue remains as to why the poleward expansion is largest in autumn, and there is still uncertainty about the role of external forcings – such as greenhouse gases – as climate models underestimate the southward expansion of the Hadley cell edge.
This research was conducted through CSIRO’s Water for a Healthy Country Flagship, and was funded by the Goyder Institute for Water Research and the Australian Climate Change Science Programme. Wenju Cai, Tim Cowan and Marcus Thatcher are from CSIRO’s Marine and Atmospheric Research division.
UPDATE:
Some commenters can’t look beyond the title and see the bigger picture, so here’s an update just for them. Note that the study deals with the Hadley cell, which is NOT regional, but hemispherical. They looked not only at Australia, but also rainfall in southern-coastal Chile and southern Africa.
This is where I was coming from, which I thought would be obvious to anyone who’s been following the positive water vapor feedback issue for any length of time.
http://www.gfdl.noaa.gov/bibliography/related_files/hall0001.pdf
===============
Abstract. Using two versions of the GFDL coupled ocean-atmosphere model, one where
water vapor anomalies are allowed to affect the longwave radiation calculation and one
where they are not, we examine the role of water vapor feedback in internal precipitation
variability and greenhouse-gas-forced intensification of the hydrologic cycle. Without
external forcing, the experiment with water vapor feedback produces 44% more annualmean, global-mean precipitation variability than the one without.
We diagnose the reason for this difference: In both experiments, global-mean surface temperature anomalies are associated with water vapor anomalies. However, when water vapor interacts with longwave radiation, the temperature anomalies are associated with larger anomalies in surface downward longwave radiation. This increases the temperature anomaly damping through latent heat flux, creating an evaporation anomaly.
The evaporation anomaly, in turn, leads to an anomaly of nearly the same magnitude in precipitation. In the experiment without water vapor feedback, this mechanism is absent. While the interaction between longwave and water vapor has a large impact on the global hydrologic cycle internal variations, its effect decreases as spatial scales decrease, so water vapor feedback has only a very small impact on grid-scale hydrologic variability. Water vapor feedback also affects the hydrologic cycle intensification when greenhouse gas concentrations increase. By the 5th century of global warming experiments where CO2 is increased and then fixed at its doubled value, the global-mean precipitation increase is nearly an order of magnitude larger when water vapor feedback is present.
The cause of this difference is similar to the cause of the difference in internal precipitation variability: When water vapor feedback is present, the increase in water vapor associated with a warmer climate enhances downward longwave radiation. To maintain surface heat balance, evaporation increases, leading to a similar increase in precipitation. This effect is absent in the experiment without water vapor feedback. The large impact of water vapor feedback on hydrologic cycle intensification does not weaken as spatial scales decrease, unlike the internal variability case. Accurate representations of water vapor feedback are therefore necessary to simulate global-scale hydrologic variability and intensification of the hydrologic cycle in global warming.
=================
So if positive water vapor feedback were occurring, based on this idea, we’d see an “intensification of the hydrologic cycle”, i.e. more rainfall, runoff, and evaporation. That would apply to the southern hemisphere continents too.
And the researchers by their own admission can’t even fit GHG feedbacks into the Hadley cell migration equation successfully. It is just more evidence of uncertainty in the “settled science” of AGW.
Please stop, Mr. Boehm,
Ohh, It hurts too much when you say “Retract your lie, grimsmud. Or everyone will see you as the alarmist propagandist that you are”. Please stop! I am afraid that you will soon be telling everyone about my grandmother and her preference for military footware!
Couldn’t you instead contribute something of a scientific nature – with a bit of content in it. For example, look back at my very first post on this threat – long before our discussions were make silly and mundane by initial entrance of RC. I asked there a straightforward and honest question concening the title of this post.
Your turn, and if you take it, please try to restrict your comments to scientific, as hard as that might be for you. Whether I am an alarmist or whether you are a BS artist has no bearing on what Mother Nature is likely to do in responce to the impacts of mankind.
Thanks, Mr. grimsmud (to you)
To bushbunny,
My apologies for referring to you as “pushbunny”. It was not intentional. As everyone has undoubtedly noted, I misspell often while posting (I wonder how many errors I have in this short comment). Or perhaps I just thought that a “b” becomes a “p” downunder where you live. In any case, no disrespect was intended and I deserved any retort you might have provided.
Sincerely, EricGrimsod
To Gary Pearse who said to me:
“I suspect that you and other ozone hole experts are largely unaware that the magnetic susceptibilities of oxygen and ozone are quite different: that of O2 is paramagnetic and attracted to a magnetic field whereas O3 is diamagnetic and is pushed away from a magnetic field. This effect would be to create an ozone hole at the poles. Maybe CFCs also have the celebrated effect, but magnetics might just be enough to account for it!”
Yes I am aware of the fact that O2 surprizingly has 2 unshared pairs of electrons and, therefore, is paramagnetic. In teaching Gen Chem many times, we even did the experiment many times in which liq O2 was suspended in air between the two poles of magnet. However, I don’t get the part about a diamagnetic substance being “pushed away” by a magnetic field. I thought that any interactions between a diamagnetic substance and a magnetic field would be too small to be of importance.
Thanks for this observation and I look forward to your response to my followup question.
Eric
ericgrimsrud says:
October 6, 2012 at 9:22 am
“I do tend to pay far more attention to the peer-reviewed literature than I do the information provided on websites.
That possibly explains why I feel like a black man and a KKK rally while participating on this web site. Nevertheless, I thank WUWT for at least letting me in the door. The only complaint I would have is that when some of the WUWT regulars heap personal insults on me, I am not always allowed to respond in kind.”
eric, you in fact just did respond “in kind”, at least according to your own feeling of being black at a good ol’ Democrat KKK rally instead of actually being at WUWT.
The problem with the particular “peer review” world which you seem to inhabit is that its CO2 = CAGW hypotheses have not produced even one relevant correct prediction yet, a point that this main blog post supports by referring to a “peer reviewed” study from the publishers of Nature!
ericgrimsrud
We have recently seen the ozone hole ‘recover’ somewhat at the same time as the stratosphere has stopped cooling.
That suggests a link between ozone amounts and stratospheric temperatures. That is hardly surprising because it is well established that that the presence of ozone in the stratosphere is the cause of the temperature inversion between tropopause and stratopause.
The change in trend of stratospheric temperatures appears to coincide with the fall in solar activity from cycle 23 to 24.
It therefore seems likely that both the changes in ozone amounts in the stratosphere AND the temperature trend in the stratosphere are dictated by the level of solar activity.
We can rule out CO2 as a factor because CO2 emissions continued to rise despite the observed change in the trend of stratospheric temperatures.
One could say that the ozone amounts recovered because of reducing human emissions of CFCs but that proposition would put CFCs in absolute control of climate variations.On that basis we have solved any problem already via the Montreal Protocol and need not consider CO2 at all.
The problem you then have is that we have seen similar climate variations before such as Roman Warm Period, Dark Ages, Mediaeval Warm Period, Little Ice Age and the Current Warm Period all long before CFC emissions and all those changes correlate well with solar variations.
What is your position in light of all those facts ?
Eric said
‘Or better still perhaps the suggestion that the ozone holes are produced by the CFC’s is all a big hoax. So Tonyp, take you pick and carry on with that line of thought if you wish.’
Eric, we were having a perfectly reasonable discussion before you went off at this absurd tangent.
I never suggested for a moment that the ozone hole was a hoax any more than I think that CAGW is a hoax.Why make such a leap in the dark to suggest that i have that line of thought?
I am merely pointing out-and Cambridge Universty and Max Planck institute agree- that with the ozone hole we have only a very recent history and any sceptic is surely going to wonder what occurred prior to the very recent instrumental readings.
We can observe a temperature rise for 350 years and also know the MWP was at least of comparable warmth to today, so we can reasonably assert that -based on science-we know that todays conditions are not unique. It may be that similarly- if we could backtrack a thousand years- the ozone hole might be found not to be unusual.
Can I suggest you read one of the papers by Quing Bin Lui on ozone and stop suggesting that I might believe the Romans produced cfc’s or I believe it to be a hoax. The proper response from a scientist would surely be ‘we don’t know.’
tonyb
JPeden, A couple of responses here to you post above.
You think my “in kind” responses have made it throught the filter at WUWT, do you. Do you not realize that what you read is only what made it through. Just as well, at least the moderators at WUWT read my originals and they own WUWT, not me, and have the right to control what they want to public to see.
Concerning whether or not we have yet seen “convincing” evidence of AGW depend on one’s definition of the word, convincing. You appear to be too smart to be fooled by trivial changes such as those occurring in the Arctic, in vast semiarid regions of the world, Greenland, the frequency of extreme weather events, East Pakistan, changes in rainfall in many formerly lush regions of the world, ect. So I won’t go into these and, instead, try another approach.
The only thing we have going for us today is the “thermal inertia” of the Earth – due mainly to the great mass of our our oceans and land ice. It takes a while for any heating effect to overcome such a large themal inertia. If you place an electric iron on a snow covered sidewalk, it would also take a while to see the effect of the iron’s heating. Keep coming back after several hours, however, and the effect of the iron will become increasingly noticable. That’s the only factor we have going to us – that is, the time lag between the causes of AGW and the final effects. Since the lifetime of the EXCESS CO2 we presently have in our atmosphere, that “iron” is not going to be unplugged for many centuries. You and I are now seeing only the beginning of changes. Our grandchilden will be witnessing far more convincing evidence by the time they are young adults and very likely be overwhelmed by them in the latter portions of their lives.
So three cheers for thermal inertial, It is the only thing the contrarians have going for them today. I only wish we had much more of it – because I happen to love my grandchildren and I wish they could plan for a future similar to that we have been blessed with.
[You (your replies) have NOT been cut, killed, trimmed, or eliminated. The Mods.]
From ericgrimsrud on October 6, 2012 at 8:26 am:
If that is indicitive of your scientific understanding of the ozone “hole”, then I am impressed, at your lack of knowledge.
See this collection of images of the region of ozone deficit known as the “hole” from 1995 to 2007, note how it is always surrounded by a region of ozone surplus.
Read this piece from January 2011, New rate of stratospheric photolysis questions ozone hole. As quoted from the linked Nature article:
The evidence is clearly pointing to the “ozone hole” being a natural effect caused by the Polar Vortex. This was recently thoroughly discussed in the comments of an August 2012 WUWT post, this link to it goes right to a highly informative comment by WUWT regular “Just The Facts”.
Since the ozone “hole” that forms within a ring of ozone surplus is a natural effect arising from the Polar Vortex, you would have to argue the CFC’s caused the vortex to say CFC’s caused the ozone hole.
Hopefully this knowledge will further your scientific education, thus allowing you to not have to resort to such extreme sarcasm when confronted on your obvious lack of scientific knowledge.
“The only thing we have going for us today is the “thermal inertia” of the Earth – due mainly to the great mass of our our oceans”
That would be thousands of years then, not hundreds.
Nothing to worry about at all.
Even assuming the thermal effects of more CO2 can get into the oceans in the first place against the net cooling effect of more evaporation.
But CO2 is no longer an issue anyway because the stratosphere stopped cooling despite increasing CO2 so the initial premise is falsified.
to Stephen Wilde, You say:
“we have seen similar climate variations before such as Roman Warm Period, Dark Ages, Mediaeval Warm Period, Little Ice Age and the Current Warm Period all long before CFC emissions and all those changes correlate well with solar variations.
What is your position in light of all those facts ?”
I say this:
First are they indeed “facts” concerning the entire globe? There is a great difference, you know between global average climate and local and regional weather. But let’s for the moment assume that the periods you mention reflect a global average.
CFC,s of course had nothing to do with anything until the last few decades. Then they mainless affected ozone levels in the stratopshere and since ozone is a GHG, have probably had an affect on climate and the overall dynamics of the atmosphere.
Concerning the more ancient events you mentioned: let’s start by remembering one important point The average surfice T of the Earth is determined by just 3 factors (see my shot course on my web site for elaboration). These are the intensity of the Sun, the albedo (reflectivity to incoming sunlight) and the greenhouse effect. The last two of these can be affected by events occurring on the Earth – for example, the eruption of a very large volcano can send particles into the stratosphere that will stay their for 2 to 4 years during which time they will increase the aldebo of the Earth and cause some cooling.
So the significant global changes that undoubedly occurred in the near and very distance past had to be caused changes in any one or more of these three variables, the intensity of the Sun, the albedo, or the greenhouse effect, a change in the average T and climate of the Earth would have occurs.
So let’s consider : what if we find in the ancient literature that a warming trend occurred in the 5 th century BC. What caused it? We would not know because we do not have sufficient records concerning the 3 factors involved. We can be sure, however, that if a change occurred it was due to changes in one or more of those 3 factors. The same is true for all other events prior to the modern age of science when people finally were able to make and save such records.
IN the last century or two, we have become much more aware of all factor affecting those three varibles. So if you are saying that the predictions that we can now make based on modern measurements are no good because we cannot explain all of the past, I think you have to give that notion some more thought. It makes no sense. Of course we can not explain what is called the Roman Warm Period. We do not have suffient information concerning what was happing all over the globe. We don’t even know if was a regional or global phenomenon. Concerning the Little Ice Age, do we know, just to pick one possibility, were their a series of very large volanic eruptions prior to that which might have set off a cooling period via the injection particle into the air. Note also that a human being might not have noted that change in atmospheric conditions – for example, after Pintatubo went off in 1991 and significantly cooled the Earth for about 2 years, did you note a change in appearance of the atmosphere whose stratosphere then contained more particles? I did not , but modern instrumentation did.
In short, we can explain our current climate conditions far far better than historic ones – for very good and obvious reasons. To discount the former because we are not so good at the latter is foolish as well as suicidal.
“In short, we can explain our current climate conditions far far better than historic ones ”
How can you know that ? What is the test ?
Unless one understands historical changes one cannot understand current changes.
Your long post is of no value and fails to address the pertinent points.
to the Mods, concerning your comment,
“You (your replies) have NOT been cut, killed, trimmed, or eliminated. The Mods.”
Please lets no even go there. You know as well as I that I have a lot of evidence to the contrary concerning my submissions to WUWT in recent months. But please so know that I also do not want to go there. It is off the scientific points and, furthermore, I recognize that WUWT is yours to run and manage as you prefer. Also note that I am not complaining. I only want to beat down a false statement before it morphs into a fact and then used irresponsibly by some of the folks at WUWT who are continuously trying to undermine my reputation and input to WUWT.
“So the significant global changes that undoubtedly occurred in the near and very distance past had to be caused changes in any one or more of these three variables, the intensity of the Sun, the albedo, or the greenhouse effect, ”
We have recently seen that global albedo changes when the climate zones shift latitudinally and/ or the jetstream tracks change their degree of meridionality / zonality.
We saw just such changes from LIA to date with no involvement of human sourced CO2. There is evidence of a similar shift from MWP to LIA.
I accept that more GHGs would have a similar effect on the atmospheric circulation but the evidence is that any such effect from human emissions is miniscule compared to the natural variations.
I would guess that our emissions might shift the global air circulation less than a mile compared to 1000 miles from MWP to LIA and LIA to date.
To Stephen Wilde,
NOT!! It takes a few decades, not centuries to overcome the thermal inertia of the oceans. In addition, remember that inertia works both ways – what takes a long time to warm up takes a long time to cool off.
To Climatereason,
OK sorry if I did not know where you where going with your argument about the likelihood of prior ozone holes in the Antarctic. I find it hard to imagine that there would have been one because we know that the one we now have is due the the CFC’s and, as you agree, the Romans or Neanderthals of Mother Nature very likely did not make CFC’s in the past. So that leaves you exploring with an entirely difference mechanism that might possibly have produced ozone holes in the past even though we don’t know that there have every been any. And of course, I agree with you that we also don’t know for sure that their have never been ozone holes before. I cant’ image what that would be, however, would be very pleased to read anything you can point me to on that topic.
If true if would be most interesting, of course, but also would likely have little to do with our present ozone hole problem, right? Our present one appears to have been caused by the CFC’s and will presist until the CFCs decrease sufficiently during the next a few centuries via their contact with UV light when they very occasionally find themselves near the top of the stratosphere – leading to a very slow net process.
Nevertheless, because it is an interesting thought, please do point me to literature that shows how ozone holes can occur via mechanisms other than that presently operative in our Antarctic. I am all ears. If this mechanish is described in one of Dr Lui’s papers please point out to me which one that would be. Thanks, EPG
To Stephen Wilde, You just said,
” I accept that more GHGs would have a similar effect on the atmospheric circulation but the evidence is that any such effect from human emissions is miniscule compared to the natural variations.”
My own understanding is that the emissions of CO2 for example by plants and those from the oceans are each about 100 Gitatons (of carbon) per year while that due to fossil fuel combustion is about 7 to 8 Gitatons per year. Note also that the fossil fuel carbon is added to the tolal biological carbon every year, year after years, thus increasing the total carbon in the air, ocean, and plants by that much each year. Thus, we have about 800 Gigaton of C in the atmosphere today while we had only about 550 Gigatons C in the atmsphere prior to the industrial age.
And you call the human emissions miniscule comparted the the natural ?? !!! Why not trying to think it through again. If you like, we can try to see which of us is full of it right here. It is an extremely important point that we can not afford to have misunderstood by the public. So in responding please do not change the subject
Your turn
ericgrimsrud says:
“My own understanding is that the emissions of CO2 for example by plants and those from the oceans are each about 100 Gitatons (of carbon) per year while that due to fossil fuel combustion is about 7 to 8 Gitatons per year.”
Wrong, as usual. Grimsrud misunderstands even the most basic facts. Human emissions are only around 3% of the total of about three quarters of a million gtons. And that ratio is the same number whether you’re measuring CO2 or ‘carbon’.
Stephen, Again you say things are transparently silly, though very commonly encountered in the contrarian “literature”, when you said,
“Unless one understands historical changes one cannot understand current changes.” Uffda !!!
The reason why we have a chance of understanding our present environment and climate is because of the scientific advancements we have made in recent decades in measuring all of the myriad factors: those that affect both the albedo and greenhouse effects and also the instruments which after about 1975 could be mounted on satalites – making accurate measurements of solar intensity possible without interferances from the atmosphere.
Studies of the past are important but the far greater difficulties presented in them should not restrict our much better understanding of the present. Your suggestion is one that would prevent action against AGW forever – which just might possibly be the only reason you made it.
D Böehm just said
ericgrimsrud says:
“My own understanding is that the emissions of CO2 for example by plants and those from the oceans are each about 100 Gitatons (of carbon) per year while that due to fossil fuel combustion is about 7 to 8 Gitatons per year. Wrong, as usual. Grimsrud misunderstands even the most basic facts. Human emissions are only around 3% of the total of about three quarters of a million gtons. And that ratio is the same number whether you’re measuring CO2 or ‘carbon’.”
Now lets see: my calculator says 7 divided by 100 + 100 gives 0.035 or 3.5%. Mr Boehm gets 3 % from his sources and makes a big deal about the difference – I am “Wrong” he says. Is it his calculator or his brain that has a few loose screws. In any case, if 3 % is the more accurate number (and human emissions do vary from year to year) , that number will also work for my intended purpose above.
From ericgrimsrud on October 6, 2012 at 1:00 pm:
So you are saying: PLEASE don’t even try to DENY it as I have PROOF you have been CENSORING and DISTORTING my words for months, it is obviously TRUE, but it is YOUR SITE so you can CENSOR and DISTORT my words AS YOU CHOOSE and YOU HAVE OBVIOUSLY DONE SO.
Put up or shut up.
Hurling accusations without providing proof, throwing out ‘you know what you did’ as justification, basically stating WUWT is as bad as sites like ReallyRealClimate and SkepSci in their moderation, with those sites just as justified in doing so for the same reason, that you have done.
Stating in classic passive-aggressive fashion ‘Now I’m not complaining’… What, you think you’re on a Seinfeld episode? Actually, maybe you do, as you also tossed out “Not that there’s anything wrong with that”…
grimsrud, I pointed out that your claimed total natural CO2 emissions 200 gtons, when the actual amount is much higher. When you’re wrong, you’re wrong.
To the Mods, As you know I objected the your recent comment to me because it was not true and because I thought if I corrected it right away the bottom feeders might not rise to bait. Wrong!!! as is beautifully illustrated by kadaka (KD Knoebel) above. Note how long and spirited it is. While not being able to contribute to the science around which this threat is based, he finally found his niche. The force of Hate over reason should never be underestimated and some are blessed with so much of it. Thus, web sites like this one do a great public service in letting our scientifically illiterate wackos vent.
REPLY: The “force of hate”? Scientific illiterate wackos? Why not tell us what you really think? I find your comment emotionally ironic.
I think you need to step back a bit and get some quiet time for yourself. If you don’t like the comment policies here, which have worked quite well now for over 900,000 comments, approaching a million, you are welcome to defer from commenting further. You can take your knocks and continue, or be upset and stay away, your choice. But, know that your comment above is out of line, but I’ll tolerate your emotions to help get the point across this one time. – Anthony Watts
D Böehm just said:
“grimsrud, I pointed out that your claimed total natural CO2 emissions 200 gtons, when the actual amount is much higher. When you’re wrong, you’re wrong.”
OK so why did you also get about 3 %, the same number I got using my numbers. If my numbers are wrong and yours are why do we get the same result.
ericgrimsrud,
Where did you get your “200” total? Was it your own WAG? Or did you find it at RealClimate, or SkS?
To D Boehm,
Concerning your assignment to me, “where did I get my value of about 200 gton for natural emissions” I get it everywhere I look using a google search for “Carbon cycle”. For example have a look at “the carbon cycle” at NOAA’s web site on climate change or that any other government agency of the USA. Sorry, but as far as I a can tell the total natural emissions of CO2 appear to be about 200 gton per year.
So new, of course, I must ask you how you are coming on your assignment. That is how did you arrive at the same fraction, about 3 % for fossil fuel versus natural emissions as I did using different numbers.
In addition, can you show us where you got you number for tolal natural emissions of 750,000 gtons per year, which is many times greater than mine (200 gtons). Looking forward to your report. If you require any addition detail concerning mine, don’t hesitate to ask.