There’s no predicted hotspot in the upper troposphere, and cooling of the stratosphere is now the new indicator. New paper finds “greenhouse cooling” of the stratosphere over past 52 years
A new paper published in Atmospheric Chemistry and Physics finds the stratosphere of the Northern Hemisphere cooled over the past 52 years due to the increase of greenhouse gases. The paper suggests that stratospheric cooling is a “more suitable” signal of anthropogenic global warming than trying to find a mid-troposphere hot spot (which was previously considered to be the definitive “fingerprint” of man-made global warming, but still has not been found despite millions of weather balloon and satellite observations over the past 60 years):
According to the authors,
A major open question that still remains to be answered is whether the stratosphere can be considered as a more suitable region than the troposphere to detect anthropogenic climate change signals and what can be learned from the long-term stratospheric temperature trends. Indeed, the signal-to-noise ratio in the stratosphere is, radiatively speaking, more sensitive to anthropogenic GHG forcing and less disturbed by the natural variability of water vapour and clouds when compared to the troposphere. This is because (a) the dependence of the equilibrium temperature of the stratosphere on CO2 is larger than that on tropospheric temperature, (b) the equilibrium temperature of the stratosphere depends less upon tropospheric water vapour variability and (c) the influence of cloudiness upon equilibrium temperature is more pronounced in the troposphere than in the stratosphere where
the influence decreases with height (Manabe and Weatherald,
1967). Furthermore, anthropogenic aerosols are mainly
spread within the lower troposphere (He et al., 2008), and
presumably have little effect on stratospheric temperatures.
Another open question is whether the lower stratosphere
has been cooling in the time since a reasonable global network
became available, i.e. after the International Geophysical
Year (IGY) of 1957–1958. Such a long-lasting cooling
from the 1960s until today would need to be explained.
To what extent are the cooling trends in the lower stratosphere
related to human-induced climate change? Has the
cooling been accelerating, for instance at high latitudes in
winter/spring due to ozone depletion? Has it been interrupted
by major volcanic eruptions and El Niño events (Zerefos et
al., 1992) or large climatological anomalies.
This study addresses those questions and presents a new
look at observed temperature trends over the Northern Hemisphere from the troposphere up to the lower stratosphere in a search for an early warning signal of global warming, i.e. a
cooling in the lower stratosphere relative to the warming in
the lower atmosphere.
Further, many warmists claim any source of warming including solar activity, cloud changes, ocean oscillations, etc. would cause a mid-troposphere “hot spot” and overlying cooling of the stratosphere, and would not necessarily be a signal or “fingerprint” of anthropogenic global warming.
The authors also find from 1958-1979 the lower troposphere either slightly cooled or remained unchanged, followed by significant warming 1980-2010:
From 1958 until 1979, a non-significant trend (0.06 ± 0.06 °C decade−1 for NCEP) and slightly cooling trends (−0.12 ± 0.06 °C decade−1 for RICH) are found in the lower troposphere. The second period from 1980 to the end of the records shows significant warming (0.25 ± 0.05 °C decade−1 for both NCEP and RICH). Above the tropopause a significant cooling trend is clearly seen in the lower stratosphere both in the pre-1980 period (−0.58 ± 0.17 °C decade−1 for NCEP, −0.30 ± 0.16 °C decade−1 for RICH and −0.48 ± 0.20 °C decade−1 for FU-Berlin) and the post-1980 period (−0.79 ± 0.18 °C decade−1 for NCEP, −0.66 ± 0.16 °C decade−1 for RICH and −0.82 ± 0.19 °C decade−1 for FU-Berlin).
Thus, although it appears the stratosphere may be cooling, and this could be due to increased greenhouse gases, there is still no evidence of a mid-troposphere “hot spot” predicted by climate models. The slight cooling to no change of lower tropospheric temperatures from 1958-1979 found by this paper also don’t support AGW theory since CO2 levels rose ~7% during that period.
The paper:
Atmos. Chem. Phys., 14, 7705-7720, 2014
www.atmos-chem-phys.net/14/7705/2014/
doi:10.5194/acp-14-7705-2014
C. S. Zerefos, K. Tourpali, P. Zanis, K. Eleftheratos, C. Repapis, A. Goodman, D. Wuebbles, I. S. A. Isaksen, and J. Luterbacher
Abstract
This study provides a new look at the observed and calculated long-term temperature changes from the lower troposphere to the lower stratosphere since 1958 over the Northern Hemisphere. The data sets include the NCEP/NCAR reanalysis, the Free University of Berlin (FU-Berlin) and the RICH radiosonde data sets as well as historical simulations with the CESM1-WACCM global model participating in CMIP5. The analysis is mainly based on monthly layer mean temperatures derived from geopotential height thicknesses in order to take advantage of the use of the independent FU-Berlin stratospheric data set of geopotential height data since 1957. This approach was followed to extend the records for the investigation of the stratospheric temperature trends to the earliest possible time. After removing the natural variability [it is impossible fully distinguish natural variability from anthropogenic] with an autoregressive multiple regression model our analysis shows that the period 1958–2011 can be divided into two distinct sub-periods of long-term temperature variability and trends: before and after 1980. By calculating trends for the summer time to reduce interannual variability, the two periods are as follows. From 1958 until 1979, a non-significant trend (0.06 ± 0.06 °C decade−1 for NCEP) and slightly cooling trends (−0.12 ± 0.06 °C decade−1 for RICH) are found in the lower troposphere. The second period from 1980 to the end of the records shows significant warming (0.25 ± 0.05 °C decade−1for both NCEP and RICH). Above the tropopause a significant cooling trend is clearly seen in the lower stratosphere both in the pre-1980 period (−0.58 ± 0.17 °C decade−1 for NCEP, −0.30 ± 0.16 °C decade−1 for RICH and −0.48 ± 0.20 °C decade−1 for FU-Berlin) and the post-1980 period (−0.79 ± 0.18 °C decade−1 for NCEP, −0.66 ± 0.16 °C decade−1 for RICH and −0.82 ± 0.19 °C decade−1 for FU-Berlin). The cooling in the lower stratosphere persists throughout the year from the tropics up to 60° N. At polar latitudes competing dynamical and radiative processes reduce the statistical significance of these trends. Model results are in line with reanalysis and the observations, indicating a persistent cooling (−0.33 °C decade−1) in the lower stratosphere during summer before and after 1980; a feature that is also seen throughout the year. However, the lower stratosphere CESM1-WACCM modelled trends are generally lower than reanalysis and the observations. The contrasting effects of ozone depletion at polar latitudes in winter/spring and the anticipated strengthening of the Brewer–Dobson circulation from man-made global warming at polar latitudes are discussed. Our results provide additional evidence for an early greenhouse cooling signal in the lower stratosphere before 1980, which appears well in advance relative to the tropospheric [assumed] greenhouse warming signal. The suitability of early warning signals in the stratosphere relative to the troposphere is supported by the fact that the stratosphere is less sensitive to changes due to cloudiness, humidity and man-made aerosols. Our analysis also indicates that the relative contribution of the lower stratosphere versus the upper troposphere low-frequency variability is important for understanding the added value of the long-term tropopause variability related to human-induced global warming.
(this post via the HockeySchtick)
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About that missing hot spot in the upper troposphere
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TOm T:
“OMG not this junk again. This all goes back to a bad post by Gavin in 2004 where he incorrectly attributed the physical cause of stratospheric cooling.”
No, Tom, it doesn’t go back to Gavin or anyone else in 2004., Since your post seems to be an attempted rebuttal of mine I would invite you to actually read it. You will see that the “junk” long antedates Gavin, going back to 1967. As for the posts you reference both support my contention that increased concentrations of heat trapping gases (aka greenhouse gases, not necessarily CO2) in the troposphere will warm the troposphere and reduce heat transport up to the stratosphere leading to stratospheric cooling. to quote from the 2nd of your references:
” For instance in the second of the references we read “This implies that there is a level in the atmosphere (called the effective radiating level) that must be at the effective radiating temperature (around 252K). This is around the mid-troposphere ~ 6km. Since increasing GHGs implies an increasing temperature gradient, the temperatures must therefore ‘pivot’ around this (fixed) level. i.e. everything below that level will warm, and everything above that level will cool.”
Note that all this occurs independent of the presence of ozone, so the Schmidt reference you cite in support of your “ozone is required for stratospheric cooling” actually undermines your claims.
You go on to say that the Zerofos et al. paper
” never make the physical connection between the actually greenhouse gas effect and stratospheric cooling.
“Well, Anthony provides us with only a fairly short extract, so you are not in aposition to claim this. Moreover, I think through sentences such as “To what extent are the cooling trends in the lower stratosphere related to human-induced climate change? ” make their aims pretty clear.
“This is called lying by context something that is very common amongst academics because they have the emotional mentality of a 4 year old and cannot grasp that there are forms of lying beyond lies of commission.”
I don’t suppose you have any evidence to support this extraordinary accusation on a very large section of the human race. Have you?
From the original post:
and cooling of the stratosphere is now the new indicator.
Not really very new, this has been known for sometime.
E.g. Manabe and Wetherald, 1967, Journal of Atmospheric Sciences: ‘Thermal Equilibrium of the Atmosphere with a Given Distribution of Relative Humidity’.
Who said: “The larger the mixing ratio of carbon dioxide, the colder is the equilibrium temperature of the stratosphere”.
More quantitatively Clough and Iacono (1995, JGR, vol 100) calculated the contributions to cooling by various gases with altitude and showed strong cooling between 100mb and 0.1mb peaking about 1mb. There was also some cooling by O3 in the same region but warming down to about 200mb. The cooling rates increased as the CO2 concentrations were increased.
Bill Illis:
Does the effect of volcanoes exclude the effect of CO2?
Climate Weenie says:
August 4, 2014 at 3:13 pm
Bill Illis:
Does the effect of volcanoes exclude the effect of CO2?
————————————–
There is no CO2 signal in the data. We are closing in on 19 years of rising stratosphere temperatures now which can only be the result of Ozone rebuilding after the effects of Pinatubo. The data shows that it takes up to 25 years for the Ozone to rebuild (perhaps more). The Earth is lucky that these large stratospheric eruptions are very rare. Before El Chichon in March/April 1982, the last two stratospheric eruptions occurred in 1963 and 1919.
Bill Illis
“The lower stratosphere does not exhibit a GHG signal. It shows a volcano/Ozone depletion from volcanic sulphates signal (and I am tired of climate scientists not recognizing this)”.
Bill, If you researched a little harder into what climate scientists do recognise of you might be pleasantly surprised. Here is, of all people, Gavin Schmidt recognising just that:
http://www.realclimate.org/index.php/archives/2006/11/the-sky-is-falling/ . See para 2.
http://www.realclimate.org/index.php/archives/2004/12/why-does-the-stratosphere-cool-when-the-troposphere-warms/ See para 7.
Happy reading!!
As for your claim that there is no GHG signal, as Schmidt points out it tends to be masked by the other effects that you mention in thelower stratosphere.
However, it is much clearer in the upper stratosphere as the graphs marked “50-30 hPa” (low pressure means high altitude) in Anthony’s article do indicate
Bill H.
ClimWee,
Hopefully that answers a point you made earlier in response to my article.
I’m going to sign off now and probably not return to wuwt for some time. I’ve enjoyed our alltoo brief correspondence, but the general level of vitriol lurking around this site gets me down too much. Witness Tom T.’s appalling slur on academics as a class (compulsive liars with the emotional development of 4 year olds). Is there something about AGW-phobia that induces such hatred of scholars?
All the best, Bill H
Greg Goodman says: August 4, 2014 at 10:22 am
“Yes signal to noise is a lot better in stratosphere and we can see straight away what is causing the cooling. Volcanoes.
0.5K drop after each event.”
But volcanoes have been erupting since forever. And the stratosphere hasn’t liquefied.
Bill H. says:
August 4, 2014 at 3:41 pm
Bill Illis
“The lower stratosphere does not exhibit a GHG signal. It shows a volcano/Ozone depletion from volcanic sulphates signal (and I am tired of climate scientists not recognizing this)”.
Bill, If you researched a little harder into what climate scientists do recognise of you might be pleasantly surprised. Here is, of all people, Gavin Schmidt recognising just that:
———————-
Oh yeah, he just cleared it all up for those reading RealBogusClimate. NOT.
Bill Illis,
I agree that the volcanoes have had an effect and even that the result is a step function of temperature around them but I don’t believe this precludes the CO2 forcing.
Here is the graph I linked earlier:
http://1.bp.blogspot.com/-qBLJ6MR2dtk/TdUpDF5VdsI/AAAAAAAAADo/cDQqeUogo_Y/s1600/StratCoolingPlot_2011.png
The 70,50, and 30 mb temperatures do indicate continued cooling since Pinatubo resolved.
Bill H.,
Despite your over inflated ego I hadn’t even read your post when I made my first post. I posted as soon as I read the article. I posted comments latter. The fact that you are making a caricature argument doesn’t make you special. It makes you generic.
On to your points first and foremost I have a pdf Manabe and Wetherald, 1967 and your statement that it says
“long wave radiation would increasingly be absorbed in the troposphere with increasing CO2 leading to less long wave radiatiion reaching the stratosphere”
Is flat out wrong. It says nothing of the sort. I don’t know what warmmonger site you read that it but it is either a very ignorant statement or a deliberate lie. All its says is “The larger the mixing ratio of carbon dioxide, the colder is the equilibrium temperature of the stratosphere”. In no way does Manabe and Wetherald, 1967 justify your claim. Maybe your original source wrongly attributed the cause due to the paper being vague.
Now in responding to Illis you re-post the 2004 post from Gavin where he admits that it the information contained therein is wrong!
You will also notice that in the 2006 RC post they don’t say that AGW is cooling the stratosphere only that CO2 is. In other words Gavin knows he was wrong in 2004 but doesn’t like to admit it.
He now simply does the same parsing of words that the authors of the subject of this article do.
“The changes in the figure are related to the cooling seen in the lower stratospheric MSU-4 records (UAH or RSS), but the changes there (~ 15-20 km) are predominantly due to ozone depletion. The higher up one goes, the more important the CO2 related cooling is. It’s interesting to note that significant solar forcing would have exactly the opposite effect (it would cause a warming) – yet another reason to doubt that solar forcing is a significant factor in recent decades. – See more at: http://www.realclimate.org/index.php/archives/2006/11/the-sky-is-falling/#sthash.1fbsFWDx.dpuf”
See Gavin no longer mentions trapped IR from the troposphere being responsible. He only makes a vague reference to “CO2 related cooling” and doesn’t really get into what that means. Your mind is left to fill in the blanks.
This is both lying by omission and lying by context. Gavin said CO2. You assumed that meant global warming. But he never said that. He left it up to you to interpret that and he knew you would.
The truth of the matter is that Gavin made his totally false 2004 post quite by ignorance but slapped down the atmospheric physicists he works with and has since pretended like it never happened. WMC actually gave Gavin a subtle jab for this mistake.
“Note: of course the fact that many people couldn’t explain this makes no difference at all to the fact that climate models produce the correct answer: they just integrate the equations, and don’t care about why things happen.”
That was a jab at Gavin.
Weenie: Here is the graph I linked earlier:
http://1.bp.blogspot.com/-qBLJ6MR2dtk/TdUpDF5VdsI/AAAAAAAAADo/cDQqeUogo_Y/s1600/StratCoolingPlot_2011.png
The 70,50, and 30 mb temperatures do indicate continued cooling since Pinatubo resolved.
===
But the lower levels do not which makes it pretty clear it is not an effect coming from below.
This part of our atmosphere is rather complex as it interacts with UV, ozone, and Rossby waves. Its bottom layer is not a consistent entity, has varying heights above sea level and varies depending on what latitude you are talking about. Its top is fairly consistent and at the same general height above sea level thus is far more stable.
This variation is why NOAA tables data into latitude and pressure level. The paper above reports one “global” stratospheric temperature. That is nuts. It could be that we are having fewer incursions of warm Rossby waves into the lower boundary of the stratosphere, or maybe more incursions of colder Rossby waves. The devil is in the details and AGW enthusiasts detest details.
http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/
Nick Stokes: But volcanoes have been erupting since forever. And the stratosphere hasn’t liquefied.
Oh well I guess the data must be wrong then, TLS is going down in steady even “trend” as predicted by AGW hypothesis. It obviously has not be homogenised properly.
Bill Innis: http://s11.postimg.org/lxwzon2rn/Volcanoes_and_Lower_Strat_Temps_1978_2014.png
Bill, I’m sure we’ve discussed this graph before and the the trends you draw are bogus, hand drawn lines. The first rising line may be about right because there was a slight bump shortly before Mt P but the 19y upward trend is a figment of your imagination.
Last time you posted that I went back and checked the linear regression over that period and it would take about 400y to recover the 0.5K drop.
If it is ozone depletion I imagine it will recover eventually but there is no sign of that in the last 19y of that data. All you’ve done it pick he lowest point and the recent high and joint the dots.
Hang on! THIS is the troposphere! We live in the troposphere. The CAGW claim, the alarmist reason why we should sacrifice our, and the poor’s, standard of life is precisely that right here, the troposphere, will warm dangerously. Now we are told, they have the chutzpah, to announce that we were right all along, that here, in the troposphere, it won’t get as hot as they said it would, as if they were right and we were wrong! What low standard of disgusting creepy dishonesty will they not stoop to (and make wildlife and the poor suffer as they do it)?
basicstats says:
On the face of it, Greg Goodman seems right about the dubious statistical methodology in this paper. There certainly are typical warning signs of problems. But the authors invoke a paper by Reinsel et al(2005) as the basis for their statistical analysis. Reinsel was a very competent statistics professor, apparently a specialist in time series and multivariate regression. In that sense anyway, it’s not from the usual half-baked school of climate statistics.
===
It’s a shame that Reinsel paper is paywalled. I’d like to see what and expert at multivariate regression does differently.
The abstract says that he is using AO and AAO + solar so it would seem to be different to the current paper. He also reports a significant difference from 1996 onwards. So it appears he notes it is basically flat since compared to 0.5K/decade ( = 0.5K / eruption ) before that.
What Zerefos et al are doing no better than fitting a bunch of AR1 synthetic data and believing it has physical meaning.
It is clear from their graphs that they are just mangling the data to the point where the clear steps are less evident. Their suggestion that this is AGW and not volcanoes is wilfully misleading in view of the literature already noting the step nature and it’s links to volcanic events (some of which are even cited).
Yet another attempt to explain away inconvenient data.
Ron House: “Hang on! THIS is the troposphere! ….”
The point is that the stratosphere is a lot less noisy than down “here”. That means some effects can be seem more clearly. It is just that which makes it so clear that the “trend” is not a trend but two steps, with a clearly identifiable cause. If we just look at tropo data the origin is not clear and it can easily be represented as a linear “trend”.
Once we recognise the cause we can also recognise it surface data:
http://climategrog.wordpress.com/?attachment_id=988
This is also what Randel 2009 finds.
I understand your rant but you are missing the point. The stratosphere is informative ( until they mangle it ).
Tom T,
Well we do seem to agree that Manabe and Wetherall predicted in 1967 that adding CO2 to the atmosphere would lead to stratospheric cooling (specifically diagram 16 on page 250 and the description on page 251), something that you describe as “junk”, when the same claim is made in 2014 by Zerofos et al. and in 2004 by Schmidt. Incidentally, Gavin makes it clear that he corrected the errors in the 2004 Realclimate post, so you are not justified in claiming that it is still in error. I didn’t find Schmidt in any way “vague”.He was as clear as M and W in 1967: increased CO2, whether anthropogenic or not, will, ceteris paribus, give rise to stratospheric cooling. All your conjectures about lying by omission and emotional levels of four year olds seem to be based on the slenderest of evidence and betray a quite scary level of misanthropy.
Since the overwhelming evidence is that the increase in CO2 in the atmosphere is due to human activity then a cooling stratosphere – particularly the upper stratosphere, where possible confounding effects of ozone depletion would be much less – would be expected, and indeed that is what Zerofos et al. have found. Essentially they provide empirical evidence to back up Manabe and Wetherall’s prediction about what will happen if CO2 is added to the atmosphere through human, or for that matter non-human agency.
As for your claims about the contrasting radiative/absorbing properties of CO2 and O3 they are actually pretty similar. Both are greenhouse gases, i.e. they absorb in the longer wave IR and both strongly absorb in the UV, x-ray and gamma ray regions to which they will be exposed in the upper atmosphere It just so happens that the long wave cut off for this is a longer in ozone – about 320 nm compared with CO2 at about 230 nm. as for CO2 being a strong radiator and weak absorber in the absence of ozone you may remember from school physics that strong radiators are also strong absorbers, and vice versa. You might have thought this only applied at the macroscopic level, but it’s a universal rule, applying to single molecules as well. You really need to come up with some references to back up this CO2/O3 model of yours.
Greg Gouldman says:
August 4, 2014 at 5:37 pm
Bill Innis: http://s11.postimg.org/lxwzon2rn/Volcanoes_and_Lower_Strat_Temps_1978_2014.png
Bill, I’m sure we’ve discussed this graph before and the the trends you draw are bogus, hand drawn lines. The first rising line may be about right because there was a slight bump shortly before Mt P but the 19y upward trend is a figment of your imagination.
————————
Greg Gouldman (since you refuse to spell my name right which is not a trait of a respectable person, I have misspelled your name on purpose – this is about the 5th time you used it as Innis) …
Sorry, the trend is UP. Yeah UP. The lower strat temps are UP. Start over with the real numbers.
Sorry for name error, not “refusal”, simple error. Apologies.
“Sorry, the trend is UP. Yeah UP. The lower strat temps are UP. Start over with the real numbers.”
Bill, how about you provide some “real numbers” instead of “UP”.
I did the calculation and unless you can come up with some valid technical criticism of the way that was done and something a lot better the “UP”, I see not need to “start over”.
m_lin = 0.00130434 +/- 0.005792 (444%)
c = 205.534 +/- 0.06168 (0.03001%)
Statistically indistinguishable from zero. No detectable recovery towards pre-eruption values.
http://climategrog.wordpress.com/?attachment_id=955
These Bozos just won’t give up! Their “gravy train” is seriously threatened. Geesh!
@Tom T … I would like to thank you for the information you provided on how CO2 operates in the stratosphere. It makes perfect sense.
So Greg, let me see what you are saying. Basically the AGW camp may have found the same mysterious layer up there that they did in the ocean, only for cold temperatures passing through. This layer allows a temperature change to go through it without detection. To be clear: The oceans are said to be hiding AGW heat in deeper oceanic layers yet we find little evidence of the transition of that heat from upper layers. Now they are saying the upper stratosphere is getting colder but we find little evidence of the transition of those colder temperatures through the lower stratosphere.
Stratospheric cooling should not be hyped as “fingerprint” of AGW especially the catastrophic kind. The cooling is predicted by greenhouse effect theory. Who’s denying greenhouse effect? But it doesn’t tell us how much warming is man-made vs. natural. And as already pointed out, stratospheric cooling can also have a natural cause.
That nasty Snowball, he is always leaving his nasty fingerprints all over the farm.
Some great examples of deflecting the argument away from the absence of a hotspot, onto stratospheric cooling seen above.
The physics are inescapable. On its own, the cooling of an atmospheric layer cannot be the cause of surface warming. This would be a completely broken argument.
The Enhanced Greenhouse Effect proposition never proposed any such thing. It proposed that CO2-driven radiative forcing (from the atmosphere) would cause warming at the surface. Radiative physics insist that layers in the atmosphere must therefore warm by more than the warming at the surface. And this point was pursued and presented in the literature by people like Ben Santer,
Stratospheric changes may have been anticipated at some stage, but if there was any cooling, it was a secondary issue and never claimed to cause surface warming.
We cannot observe the warming layers as they were predicted. The Enhance Greenhouse Effect is therefore falsified. It’s a dead parrot. A Norwegian Blue as stiff as a bedpost.
It is about as credible as a theory of fairies at the bottom of the garden. It doesn’t matter if leaves can be observed blowing around the bottom of the garden – this is not some kind of secondary observation of fairies. In the same manner, stratospheric cooling cannot be introduced as a secondary indication of warming in other layers (which cannot be directly observed).
As they say: “it’s all over, bar the shouting”