A paper published Friday in the Journal of Geophysical Research (GRL) finds that a known and natural atmospheric oscillation, the Southern Annular Mode or SAM, is correlated with observed increases in cloud cover resulting in regional cooling of approximately -2.5C. See for example this comparison from the paper with MODIS satellite data:
From UCAR:
The Southern Annular Mode (SAM), which is defined by changes in the westerly winds that are driven by temperature contrasts between the tropics and southern polar areas. The annular modes generally take a circular pattern (‘annular’ means ring-shaped) and see-saw between positive and negative phases for weeks or months. In the SAM’s positive mode, the ring is stronger and further south, inhibiting Antarctic air outbreaks. In the negative mode, a weaker, more variable vortex allows Antarctic air to spill north more easily.
The Southern Annular Mode has steadily trended positive in recent decades. Computer models indicate this trend is related to ozone depletion above Antarctica and increases in greenhouse gases. (Image courtesy Jianping Li, China Institute for Atmospheric Physics.)
As presently programmed, climate models assume clouds result in net positive feedback and increased temperatures, however this new paper and several others that have recently been published show that clouds instead result in net negative feedback and cooling.
Key Points of the paper:
- Sudden regional increases in cloud cover are detected over S. America
- Changes linked to the Southern Annular Mode
- The cloud changes are associated with regional temperature reductions
The paper and abstract:
Understanding sudden changes in cloud amount: The Southern Annular Mode and South American weather fluctuations
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 117, D13103, 7 PP., 2012
doi:10.1029/2012JD017626
Benjamin A. Laken Instituto de Astrofísica de Canarias, La Laguna, Spain, Department of Astrophysics, Faculty of Physics, Universidad de La Laguna, La Laguna, Spain
Enric Pallé Instituto de Astrofísica de Canarias, La Laguna, Spain, Department of Astrophysics, Faculty of Physics, Universidad de La Laguna, La Laguna, Spain
This work investigates the cause and effects of extreme changes in synoptic-scale cloud cover operating at daily timescales using a variety of satellite-based and reanalysis data sets. It is found that the largest sudden increases detected in globally averaged cloud cover over the last ten years of satellite-based observations occur following positively correlated shifts in the phase of the Southern Annular Mode (SAM) index. The associated pressure anomalies are found to generate frontal cloud formation over large areas of the South American continent, increasing regional cloud cover by up to 20%; these changes are correlated to statistically significant reductions in local temperatures of approximately −2.5°C with a +1 day time lag, indicating the SAM index is associated with large scale weather fluctuations over South America.
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joeldshore says:
“This does not make sense. Convection can’t do an “end run” around the greenhouse effect because ultimately the energy has to escape the Earth system via radiation.”
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“End run” is a reasonable description, joel. By nature, the top of the upward-moving convection column is warmer than the surrounding air. If it’s high enough for radiation to escape (near the tropopause) and additionally contains aerosols (condensed water/ice), it radiates outward to space as a warmer “surface” than a standard column. That’s increased heat-loss & less “insulation” effect.
This is basic. Why deny/obscure it?
Kohl says:
This is simply not correct. There have been fairly considerable variations in temperatures over the Earth’s entire history (and correspondingly huge variations in sea levels) and the IPCC projections do not place the Earth outside of this range of temperatures. They do, however, predict temperatures that would likely be higher than anything experienced for millions of years (and higher than anything experienced in the geological blink-of-an-eye that homo sapiens have beeen around).
[Only a very few scientists, like James Hansen, have claimed that we could set off some sort of runaway effect that would bring temperatures to truly unprecedented levels for essentially all of the Earth’s geological history. These claims are very speculative and it is reasonable to be quite skeptical of them (as I think most climate scientists are currently) although Hansen has made arguments why such an unprecedented occurrence could happen when it never has before.]
I am not sure why you believe this. The very same climate models that predict the response to rising CO2 levels with a water vapor feedback (a feedback which is now well-verifed by empirical data, see http://www.sciencemag.org/content/323/5917/1020.summary or http://www.sciencemag.org/content/310/5749/841.abstract ) allow for spontaneous variations in water vapor concentrations and yet they do not predict that these levels will spontaneously rise in the way that you are talking about. Clearly, your intuition here is not very good.
One of the big advantages of physical modeling is that it allows you to consider “What if…” scenarios and none of the models provide support for your hypothetical…and, in fact, the models show that a positive water vapor feedback is necessary to get good agreement with current climatology in various ways.
mike g says:
Not really. To the extent that there are knobs that can be adjusted, they are mainly adjusted to get some basic things in the current climate right, like the cloud fraction or what have you.
Every analysis of the instrumental temperature record has shown essentially the same thing, whether it be NASA GISS, Hadcrut, BEST, or various “lukewarmers” like Steven Mosher.
Actually, what you are throwing out here are just a bunch of debunked “skeptic” talking-points. You might endeavor to learn why the scientific community does not agree with your conclusions here. But, because of what I say below, they are also besides the point.
The strength of the MWP in the data has essentially nothing to do with the model predictions because, as noted, the models haven’t really been adjusted to agree with the temperature reconstructions over the last 2000 years. In fact, such a task is essentially impossible because not enough is known about the forcing variations over the last 2000 years (e.g., there is considerable uncertainty in the proxy data for solar variability over that timescale). So, while there has been some work comparing models and temperature reconstructions, the uncertainties tend to be too large to make very definitive conclusions, let alone to tune the models!
Better tests of the model estimates of climate sensitivity are provided by looking at the temperature change and forcing change between the Last Glacial Maximum (roughly 20,000 years ago) and now…Or by looking at the response to the Mt Pinatubo eruption…Or, the best by combinations of various such things.
The best way of tuning what free parameters there are in the models is provided by comparing the details of current climatology with what the models produce.
beng says:
I have clearly explained why that there is no empirical evidence or physical basis for believing that any such magic exists beyond what is already incorporated into climate models. It is incumbent on those proposing such magic to explain how it occurs and how it agrees with the empirical data.
As I noted, ultimately the only way a significant amount of radiation escapes to space is by radiation. And, how much radiation is emitted depends on temperature. Such hypotheses seem to imply something about the temperature structure of the atmosphere that there is no observational evidence to support (at least if you interpret them as implying something beyond what is already included in the models).
Joel,
“Getting rid of the MWP” is a metaphor for what they’ve done, which is to assume temperatures to have been flat back in time from the most recent minimum (70’s – 80’s) and attribute all warming since then to CO2 and feedbacks, and tweak the knobs accordingly. Which is why the model predictions fail so miserably.
Climategate wasn’t debunked. It was whitewashed.
joeldshore says:
July 8, 2012 at 6:58 am
“pochas: Just to bring you up to speed in regards to the actual science regarding convection and the greenhouse effect – The reason convection does not negate the greenhouse effect is that convection proceeds only as far as driving the temperature distribution with altitude (“the lapse rate”) down to the (appropriate, dry or moist) adiabatic lapse rate. If it were able to drive the temperature distribution all the way to an isothermal distribution with altitude (zero lapse rate) then it would indeed negate the entire greenhouse effect (as was well-known already and most recently re-discovered by Nikolov and Zeller who mistakenly put convection into a simple model in exactly this incorrect way).
Because of this limitation, convection does not cancel out the greenhouse effect, although it does reduce the natural greenhouse effect on Earth by a significant amount from what it would be with no convection. (As I recall, calculations show it would be about a factor of two larger in the absence of convection but all else equal.)”
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I did not say convection negates the greenhouse effect. I said that it reduces it significantly, and you appear to agree. It is the feedbacks on temperature change that are in dispute. So, only a minor effect from CO2, and the amplifying effect from water vapor is missing (no hot spot).
The reason it is missing is that the lapse rate is in control of the atmospheric temperature profile, and hence limits the vapor pressure of water in the moist sectors of the atmosphere. This is evident from the 30 degree “flat top” in the water surface temperatures over the oceans at the equator that Willis pointed out here. Now, dry descending air is just that: dry. So water vapor is limited by the carrying capacity of the ascending air columns in the convective zones, and higher surface temperature just intensifies the convection while the dry zones stay dry. The naive use of the Antoine equation by the IPCC and others is part of their fragile fabric of incorrect physics.
You might expect that intensified convection would result in more violent weather, but this is not seen. I speculate that the observable effects of greenhouse gasses may be higher radiative emissivity from the top of the atmosphere near the equator which means less driving force for meridional circulation which is what really causes violent “weather.” Also, there is probably some elevation of minimum temperatures at high latitudes where the air is very dry. Beneficial effects, on balance.
Thank you for your persistent advocacy of the IPCC position on climate. If you didn’t do that, we’d have nothing to discuss.
pochas says:
Whether the “hot spot” is present does not really have any bearing on whether the amplifying effect of water vapor is occurring. The most direct effect of the missing “hot spot”, were it real, would be that the assumptions that go into the lapse rate feedback, a negative feedback in the climate models are wrong, and hence that feedback is incorrectly included…So, the models would be underestimating the climate sensitivity. Admittedly, a lot of the same physics controls this lapse rate feedback and the water vapor feedback, so one might say that the water vapor feedback would be reduced too, but as Isaac Held has pointed out, the water vapor feedback can be divided into two pieces: (1) The feedback that would occur if the atmosphere warmed uniformly with altitude (and a constant relative humidity were maintained). (2) The additional feedback that occurs if the tropical troposphere warms faster than at the surface, the so-called hot spot (and again a constant relative humidity is maintained). It turns out that, although the entire water vapor feedback is larger in magnitude than the lapse rate feedback, just the second part of the water vapor feedback is smaller in magnitude than the lapse rate feedback. This means that the net effect of the missing hot spot would seem to be an underestimate, not overestimate, of the amplification of the warming by these feedbacks.
Your statement here seems to betray some confusion about the theoretical considerations that give you the “hot spot” (i.e., amplification of warming as you go up in altitude in the tropical troposphere). In fact, it is exactly the fact that the lapse rate is expected to be pegged to the moist adiabatic lapse rate that leads to the prediction of the “hot spot” (as Richard Lindzen has in fact noted, although it is not hard to come up with the basic argument oneself). So, your argument that the “lapse rate is in control of the atmospheric temperature profile” is basically just restating the accepted science.
I thought maybe you were trying to make some distinction about which adiabatic lapse rate is important (dry or moist), but I don’t see any way to read what you wrote as saying this…and don’t understand the argument you would be making on this basis at any rate.
@joeldshore
Sorry, my connection has been down and I’ve been unable to engage in this discussion (which I find quite interesting).
Perhaps this might be continued another time.
Regards,
Kohl
joeldshore says:
July 9, 2012 at 8:08 pm
” So, your argument that the “lapse rate is in control of the atmospheric temperature profile” is basically just restating the accepted science.”
Indeed! This is a good place to stop.
Joel Shore:”Admittedly, a lot of the same physics controls this lapse rate feedback and the water vapor feedback, so one might say that the water vapor feedback would be reduced too,”
There is, of course, a third piece of the water vapor feedbacks as well IMO. That is the effect of condensation on the climate system as separate from the release of latent heat that would be captured in the lapse rate feedback. For there to be lapse rate feedback, there must be more condensation and generally more condensation has a cooling effect (in the formation of clouds and in increased precipitation efficiency).
As I said above, however, assuming a more or less constant RH implies, by the Clausius-Clapeyron relationship, that condensation will increase with temperature so you are left with three types of WV feedback -the positive WV GH effect, and the negative lapse rate and condensation effects.
Cheers, 🙂
Shawnhet says:
July 10, 2012 at 12:50 pm
“As I said above, however, assuming a more or less constant RH implies,…”
I am arguing that this constant RH assumption is wrong because the atmospheric temperature profile, and hence water vapor pressure and water vapor concentration is set by gravity and the gas law. A better assumption is constant absolute humidity.
Hi pochas,
I don’t really see how constant humidity can be made to match the historical record. It seems clear to me that the humidity must be less during an ice age for instance and I believe that there are many periods that have been greener than present(which tends to suggest more WV).
In any case, my point to Joel was that it doesn’t make any sense to assert on the one hand that there will be lapse rate feedback at the same time as reduced cloudiness. For lapse rate feedback to be taking place more WV must be condensing. Since condensing water vapor is one of the building blocks of clouds, it does not make sense to argue that cloudiness will go down at the same time as condensation goes up.
It is possible that there is another process going that might lead to this combination but you can’t just assert the process’ complexity as a reason to ignore the apparent contradiction (as Joel does above).
Cheers, 🙂
pochas says:
Not if you actually do things like look at the empirical data. (And, just as a note: Constant RH is not an assumption in the climate models but something that ends up as an approximate prediction of the models. (In reality, the models don’t predict it to rigidly hold true but to hold true approximately at the global scale.)
Shawnhet says:
Frankly, I don’t see any reason why the relationship between the lapse rate feedback and cloudiness has to be as simple as you seem to think it has to be. But, hey, if you want to argue that the lapse rate feedback isn’t there, that means that the models are UNDERestimating climate sensitivity in that respect (although probably not by all that much).
joel shore says:
“…look at the empirical data. (And, just as a note: Constant RH is not an assumption in the climate models but something that ends up as an approximate prediction of the models.”
A ‘prediction of the models’, heh. They program GIGO – Garbage In, Gospel Out – so no wonder they can’t predict their way out of a wet paper bag.
The anthropogenic globaloney warming conjecture says that relative humidity will increase due to warming. Makes sense.. until you look at the empirical evidence. Maybe the temperature record isn’t quite as accurate as claimed, eh?
Smokey says:
That is false (they predict that absolute, not relative, humidity will increase) and furthermore your empirical evidence consists of cherrypicking one particular reanalysis using radiosonde data while ignoring all of the other re-[analyses and the satellite data that contradict it (i.e., that show a fairly steady or slight drop in relative humidity, which is what the models actually predict).
Reanalyses rely heavily on models, by the way, so they are not really “empirical evidence” in a strict sense. They are a combination of empirical data with modeling analysis.
Isn’t joel shore cute? He comments on “Constant RH”, and then wanders off into ‘absolute humidity’ because he was proved wrong on R.H. And he calls a chart showing R.H at various altitudes, and going back to 1948, “cherry picking”. As if.
That is ‘cherry picking’ only in the crazed mind of a deluded climate alarmist. And what is “a fairly steady or slight drop in relative humidity”? They are two difthings entirely.
Have another glass of red, joel. And maybe a valium, you need it.
Joel Shore:”Frankly, I don’t see any reason why the relationship between the lapse rate feedback and cloudiness has to be as simple as you seem to think it has to be. But, hey, if you want to argue that the lapse rate feedback isn’t there, that means that the models are UNDERestimating climate sensitivity in that respect (although probably not by all that much).”
I am not arguing agaist lapse rate feedback, I have been quite clear throughout this thread that I believe that a warming atmosphere (with constant RH) will result in more condensation (and, hence, lapse rate feedback).
You seem to have trouble with my logic, so let me lay it out in more detail. 1.Condensing water in the atmosphere is one of the building blocks of clouds. 2.The more water that condenses in the atmosphere the more (and bigger) clouds can form 3. Since a warming world with constant RH will result in increased condensation, the odds of clouds forming will be greater and more clouds on average.
You seem to be arguing for some process in place of 2 that will make cloud formation *decrease* with increased condensation. While this may be *possible*, it is your responsibility to lay this process out whatever it is supposed to be. Simply saying that it is possible that some process could take place that will make cloudiness less likely with increased condensation does not establish that such a process exists. Based on what we know of cloud formation though this seems unlikely and appears to be contradicted by real world evidence. Hot, wet climates(with lots of condensation) tend to be cloudier than cold, dry ones(with only a little).
Cheers, 🙂
Smokey says:
I don’t think you are fooling anyone but yourself here. I wasn’t proven wrong on R.H. I corrected your misperceptions about what models predict about R.H. And, the point is that your chart (which, as usual for you, is simply a graph with no context or data source given) is from one particular re-analysis that conflicts with all of the others (see http://geotest.tamu.edu/userfiles/216/Dessler10.pdf ). That is what the cherrypick is.
Well, that is part of the problem with your graph. Graphing relative humidity without any reference to what the models predict it to do is incomplete, so it is impossible to tell from your graph what if any disagreement exists. You then wrongly claimed what the models predict about R.H. (As it turns out, I believe there is some disagreement because the R.H. in your graph decreases more than the range that the models predict it to, but again that seems to be an artifact of this particular reanalysis.)
Shawnhet says:
A warmer world has more evaporation and condensation but also more precipitation, which takes the condensed water vapor out of the atmosphere. How this ends up affecting cloudiness is not obvious. As I have noted, Richard Lindzen argued that a certain type of cloudiness (high cirrus clouds in the tropics) would decrease in a warmer world. I have seen no evidence in anything that I have read on the cloud feedback (and I have a whole book…conference proceedings…on it) that suggests that one can make such simple arguments as you want to make about what will happen. If you have seen such evidence presented somewhere, I’d love to see it.
In particular, some of the clouds most important to increased albedo are low marine clouds that I believe often form over ocean waters that are cooler than the land areas (see, e.g., http://meteora.ucsd.edu/~iacob/ml_formation.html )
joel shore has a problem responding to graphs and charts that I post, because they upset his world view. A while back, joel shore objected to one of my charts, just as he objects to the chart I posted showing that relative humidity has been declining steadily at all relevant altitudes since at least 1948. That evidence indicates that AGW is far less than claimed. In fact, AGW is too small to measure.
Anyway, shore objected to a chart I had posted, so I posted fifty (50) different charts and graphs, from numerous different sources, many peer reviewed, all of which supported and verified the chart I originally posted.
joel shore’s response? joel shore rejected all fifty of them!! The conclusion is inescapable: joel shore is afflicted with incurable cognitive dissonance. He is a True Believer. The fact that Planet Earth is falsifying his True Belief means nothing to him, because his belief is religious, not scientific.
Joel Shore:”A warmer world has more evaporation and condensation but also more precipitation, which takes the condensed water vapor out of the atmosphere. How this ends up affecting cloudiness is not obvious. As I have noted, Richard Lindzen argued that a certain type of cloudiness (high cirrus clouds in the tropics) would decrease in a warmer world. I have seen no evidence in anything that I have read on the cloud feedback (and I have a whole book…conference proceedings…on it) that suggests that one can make such simple arguments as you want to make about what will happen. If you have seen such evidence presented somewhere, I’d love to see it.”
Yes, precipitation increases but if it takes moisture out of the atmosphere quicker (on average) than currently, there are two options. If RH is constant, this precipitation will be matched by increased condensation in which case, the total WV is unchanged(ie at its higher level in a warmer atmosphere) and a warmer atmosphere will have more WV(cloud building blocks) than a cooler one. Again, it is not my responsibility to explain how more WV will result in less cloudiness, I don’t think that this is what happens. You, apparently, do think that this does take place so you should try and justify this, perhaps by referring to one of your cloud feedbacks in your book.
“In particular, some of the clouds most important to increased albedo are low marine clouds that I believe often form over ocean waters that are cooler than the land areas (see, e.g., http://meteora.ucsd.edu/~iacob/ml_formation.html )”
I don’t see how the fact that cloud formation and condensation will be more likely to take place in high RH than low ones is relevant. The appropriate comparison would be to compare two climates with the same average RH but different average temperatures. I am pretty confident that, for the general case, (without any special air circulation differences), these comparisons will agree with my position and not yours.
IAC, I’m not sure what your point is here but it seems as though your reference does not support the position you are trying to make.
“The formation of these clouds usually begins when wind over the water surface mixes moist surface air upwards. As this air moves up, it expands and cools. The cooling causes the relative humidity to increase and once the relative humidity reaches 100%, condensation of water vapor into liquid water drops takes place and clouds begin form. The depth through which the air mixes is referred to as the mixed layer.
The altitude (or height) that surface air must rise for condensation to start is called the Lifting Condensation Level or LCL for short. So if air near the surface is allowed to mix upwards to the LCL a cloud will form. Under certain conditions air does not mix high enough for clouds to form, that is the top of the mixed layer is beneath the LCL. While no clouds formed, the mixing has increased the relative humidity near the top of the mixed layer and subsequent cooling of this air could increase the relative humidity to 100% and initiate cloud formation.”
From this we can see, either the air is mixed high enough in which case condensation begins cloud formation or it does not and the relative humidity near the top of the mixed level has increased (IOW RH is not constant).
Cheers, 🙂
Oops, from my first paragraph above, I forgot the second of my two options for what could happen if precipitation increased in a warmer wetter world. The second option would be to let moisture leave the atmosphere quicker than it is replaced which would cause the RH to *fall* until the precipitation was matched by the evaporation.
Smokey says:
Yes…It is. The conclusion is that you are a font of misinformation who scours the internet sites of those who are in the same ideological camp as you, finds all of the deceptive or cherrypicked graphs that they produce and reposts them here. And then, when I very patiently and carefully explain what is wrong with them, you can’t defend them, so you just go into these general diatribes.
joel shore,
As usual, you are completely wrong.
I don’t “scour internet sites”, except in your dreams. At least 99% of my time is spent on WUWT. The rest of it is spent checking out the day’s news on http://maggiesfarm.anotherdotcom.com and Drudge. That’s all [unless someone emails me a tip, or I click on a link someone has posted].
Regarding the “deceptive and cherrypicked graphs” you’re always whining about, I get them all from commenters and articles right here on WUWT. All of them. You just don’t like it, because they debunk your belief system.
As I’ve said many times before, if I had a dollar for every time you accuse someone of being “ideological”, I could have a nice dinner for four at a nice expensive restaurant. It is you who is always being ‘ideological’. Your entire world view is ideological. That’s why you are always accusing others youd disagree with of being ‘ideological’. You see everything, including science, through the lens of left-wing ideology.
The conclusion is inescapable: if it were not for your psychological projection and misinformation, you wouldn’t have much to say.☺
Smokey says:
Fine…Change “sites” to “site”, Really, you let other people scour the internet sites, you see what they link to here on WUWT, and then you save the links and bring them out in response. It doesn’t change the basic fact that you know virtually nothing about the graphs that you post and when I or someone else explains to you why they are wrong, cherrypicked, or misleading, you are unable to defend them.