Stratosphere Cooling: Investigating Causes & Effects

[Andre]

As was discussed in another thread,

However I stand by what I've said, I can't see any mechanism that accounts for the tropo. warming and upper strato cooling. ...with the panoply of technology we have, there seems no alternative to the CO2 warming theory.

About the rough idea of the greenhouse effect and the temperature of the troposphere I said:

Facts & physics: The sunlight that hits the Earth surface is absorbed by the surface, heating it. CO2 is not interfering with this. The surface heating causes reradiating of heat waves (Infra red) and some of this is absorbed by the CO2 molecules in the air, warming the air.

Hypothesis: So with more CO2 in the lower atmosphere air, (troposphere) gets warmer and since this is the first effect this trend should be the strongest. The warmer troposphere is keeping the Earth warmer but this is secondary and hence this should be the weaker trend. Due to this resistance of IR radiation the higher atmosphere, or stratosphere cools.

So we test the hypothesis and see no troposphere warming in the measured radiosonde data and a distinct lower warming trend in the calculated satellite data:

http://home.wanadoo.nl/bijkerk/ghcn-sat-son-trends.jpg

How about the stratosphere data, that would require a cooling trend.

http://www.ghcc.msfc.nasa.gov/MSU/images/strato_temp.gif

Yes, they are cooler now than usual albeit without a distinct trend. We see some distinct spikes and a distinct lasting drop between 1993 and 1994, the temperature seems to be slowly recovering again. Not nearly a steady trend inverted proportional to the increase in greenhouse gasses.

So what would be causing this behaviour of the stratosphere?

 

[CobblyWorlds]

http://www.met-office.gov.uk/research/hadleycentre/CR_data/Monthly/upper_air_temps.gif

This gif from the UK Met Office’s Hadley Research Centre clearly shows both the lower tropo and lower strato anomalies reveal trends as I stated in your first un-attributed quote. Sorry if I’m pedantic but I prefer data from professionals rather than the jpg you link to on someone’s home page

The supposed absence of trend in your strato graph I would presume is due to the spike in June 1991, remove that and there is a trend. Mount Pinatubo erupted in June 1991.

As to what the cause is…

It’s not as simple as increased CO2, although that will be a factor. There are often multiple factors involved in such issues. This paper attempts to address the observed trends and mentions 2 further factors, pg 15 and 16.

http://www.atmos.colostate.edu/ao/other_papers/ThompsonSolomon2005Accepted.pdf

CO2 caused cooling is one factor, but I understand that this is mainly in the upper stratosphere. The 2 other factors mentioned here are CFCs (which I understand to be mainly affecting the lower strato. And upwelling. As the paper itself states CFCs are not likely to play a role in the tropics due to their low concentration. And as for upwelling, if an increase in upwelling is the cause then it must be the greater tropo temps that are driving this. And where is the additional energy coming from for that? Probably CO2 driven warming due to the greenhouse effect.

I’ve only just come across this paper over the weekend so haven’t had time to fully consider it. However I stand by what I said ealier, these trends are indicative of an ongoing change in our climate.

 

[CobblyWorlds]

Sorry forgot to add:

You say "So we test the hypothesis and see no troposphere warming in the measured radiosonde data and a distinct lower warming trend in the calculated satellite data:"

Attempting to instill a distrust of the "sneaky ol' hi-tech satellite data"? ;)

Yet the calculation that goes into that is no more arcane than that applied to radiosondes.

The radiosonde sends a signal to ground which contains a stream of numbers, numbers derived from a physical measurement system. The satellite does this as well. But the satellite actually has an onboard 'black body radiator' as a reference, I'm not aware of the individual radiosondes carrying an internal ref. And 2 or more satellites can measure the same area simultaneously - thus providing a further ability for real time cross checks in the data record.

The Radiosonde datasets then need to be averaged as do the MSU data. But as I said above, a radiosonde dataset represents a point in space. The MSU covers an area. And whilst MSU data can overlap giving an opportunity for calibration, radiosondes do not 'overlap'. Although one can reaonably assume homogenaity over and area in which radiosondes are used, one can actually observe whether or not there is such homogeneity over the coverage of the MSU unit.

The radiosondes have more N. hemisphere coverage than S hemisphere. This is NOT the case in the MSU readings. Thus the MSU is not subject to the bias implied by the unequal distribution of land and sea in the N and S hemispheres.

MSU = microwave sounding unit, essentially a very specialised type of radio.

 

[Andre]

I'm not aware of the individual radiosondes carrying an internal ref

How about a simple thermometer, measuring temperatures directly?

Although one can reaonably assume homogenaity over and area in which radiosondes are used, one can actually observe whether or not there is such homogeneity over the coverage of the MSU unit.

Attempting to instill a distrust of the "sneaky ol' hi-tech radiosonde data"? ;)

Sorry if I’m pedantic but I prefer data from professionals rather than the jpg you link to on someone’s home page

Of course I'm always double crossing. So please check the official data, compare them and then you can call me a liar.

The radiosondes have more N. hemisphere coverage than S hemisphere.

Which tends to minimize the difference, after all the Northern hemisphere did the bulk of the warming.

Edit:
about differences in radiosonde and satelite as well as troposphere cooling and warming an interesting presentation (large file):

http://www.ncdc.noaa.gov/oa/ncdc_vtt_pwt.ppt#1

About the stratosphere study: http://www.atmos.colostate.edu/ao/other_papers/ThompsonSolomon2005Accepted.pdf

Perhaps there is a clue in:

Increases in stratospheric water vapor may also contribute to a meridional gradient in stratospheric cooling (Forster and Shine 1999) but trends in this trace gas remain uncertain (Randel et al. 2004).

 

[Andre]

Oh and that big presentation. This is what slide 15 says:

Since 1979 observations imply that the troposphere in the tropics has cooled whereas the surface has warmed.

This contradicts climate model projections, which predict greater warming aloft.

It is also a reversal of an earlier global-mean trend according to the longer radiosonde analyses.

It casts doubt upon our understanding of the climate system and ability to predict future climate changes.

 

[CobblyWorlds]

Attempting to instill a distrust of the "sneaky ol' hi-tech radiosonde data"? ;) LOL. Radiosonde as you imply with your 'thermometer' comment is substantially lower tech - this has been used for well over 50 years.
Certainly not dismissing the Radiosonde data, merely pointing out that both have their pro's and cons. A thermometer does not measure temperature directly. All such instruments need calibration, and in a single radiosonde unit an error may not be found by the techniques of cross-comparison I outline for MSU. However it does have to be considered that with MSU there is a risk of 'contamination' of readings from areas of the atmosphere that one does not want to measure, Fu has been working on this.

My point in presenting the Hadley Centre graphs as I do is to show that broad agreement in trend that they show. And the consistency of trend with what I stated as you initially quoted.

By no means am I calling you a liar. In January of this year, having been sceptical about the claims of warming I decided to really apply myself to the subject. I've avoided the 'green' sites, who often overstate. But by the same token I have found the arguments presented by sceptic sites poor, and in some cases based on flawed, withdrawn or superseded data, i.e. I suspect deliberate misrepresentation. THAT is why I stick to Hadley NOAA, NASA etc. I only go to academic sites when downloading courses. The only sites that don't fit my criteria here are Deltoid and RealClimate, which allow posting, so criticism of their assertions can be made, and contain what seem to me to be coherent arguments.

"Since 1979 observations imply that the troposphere in the tropics has cooled whereas the surface has warmed." This claim about the trends stands against the Global trend presented in the Hadley Centre Graph (and other data). But regional differences do not counter my argument with regards the global pattern. I do not think that climate scientists' projections are 100% correct, nor do they. (I will look at what you link to).

The bottom line is this increased CO2 is causing warming on a global scale, areas such as the Arctic are warming faster, (twice the global rate) some areas may cool. But that does not change the fact that the energy from the increase of CO2 has to go somewhere and has to have an effect. As indeed it is. What will this do in the future? Change our climate. And that's a VERY broad statement, as indeed are the projections in the IPCC Third Assessment.

Back to the issue at hand, do you discount the Hadley graphs I link to? Do you accept that Pinatubo is the cause for the disturbance to the trend in the range presented in the second graph you link to?

 

[CobblyWorlds]

Hi again Andre,

With regards the tropical cooling I've read about it before, too me a few hours to realize I was being a duffer (it's my age).

http://www.metoffice.com/corporate/scitech0102/9_climate_research/cv_global.html

Under the section 'Tropo. Lapse rates' gives a tentative explanation. But I'm afraid I have to stand by my earlier statement about regional effects.

In view of the cloud effects here, Dr Richard Lindzen has done some work showing a net decrease in radiative forcing as a result of clouds. In response Bing Lin has produced evidence to the contrary suggesting that they will not reduce warming overall, a good general explanation is available on the Nasa EarthObservatory site.

Off for the evening now.

 

[Andre]

This gif from the UK Met Office’s Hadley Research Centre clearly shows both the lower tropo and lower strato anomalies reveal trends as I stated in your first un-attributed quote. Sorry if I’m pedantic but I prefer data from professionals

So, did you discover how those profesionals indeed con us?

compare the ground station data of thehttp://www.met-office.gov.uk/research/hadleycentre/CR_data/Monthly/upper_air_temps.gif data and see that they cranked down the ground surface data a few tenth of a degree to hide the current trend. Notice also that the data on my graph remain valid.

But then again of course the PM has ordered that global warming be true.

Then realclimate. Ever bothered to count the fallacies? Any idea why contributing posts need to be screened? Any idea why this comment never got past the screening?

If I read the title:

"Global temperatures continue to rise"

I expect to read about a rise of global temperatures. As it seems that the year 2004 is under observation, the expectation generated by the verb "rise" is consequently that 2004 was warmer than the year before, whereas the verb "continue" suggest that on the average previous years were cooler than the consecutive years. But what do we see:

“2004 was slightly cooler than 2003, 2002 and 1998”. So there were already three previous years warmer and worse: “1998 remains the warmest year”, indicating that also 2002 and 2003 broke already with the rising trend. I have to conclude that the global temperatures did not continue to rise at all. Both verbs “continue” and “rise” are inaccurate. The title should have been “Global Temperatures remain above average” or something for correctness. Now it suggests being an Argumentum ad Metum a.k.a. red herring.

Ever visited the uncensored counter-balancing blog? Shall we compare the average number of fallacies per page?

 

[CobblyWorlds]

Re the graph I posted, see http://www.meto.gov.uk/research/hadleycentre/obsdata/testfile.html

This clearly states that the surface data is a plot of Sea Surface anomalies, extracted from 150W and 90W, 5N and 5S. It's not intended to display a correlation between SST and the MSU/sonde data, and I did not present it in this light.

Furthermore when you take the period of the graph I post 1960 to 2005 and compare this with the subset of the Ocean surface graph that you present for 1960 to recent there is a clear agreement in trend and degree. Furthermore, the graph I present is based on seasonal averages with a 3 month running mean, and is not automatically comparable with the June data you state. You are comparing chalk and cheese, did you not spot this, or did it suit your argument not to acknowledge it?

So on this issue, there is no evidence for the misrepresentation you incorrectly claim and I refer you to my original question. Do you not accept the graphs I present and their implication that on a global trend the strato is cooling as the tropo warms? (It is only on a global basis that I can argue because the net gain of energy due to CO2 is a net global effect, it does vary regionally and throughout the year).

You quote "I expect to read about a rise of global temperatures." I understand that you are stating that this post was one of yours that was rejected. I can understand why and fully agree with RealClimate's decision to do so. Sorry but 'one swallow does not a summer make'. WMO press release 718 starts "The global mean surface temperature in 2004 is expected to be +0.440 C above the 1961-1990 annual average (14.0C) ". This does not show that the trend as displayed in the above mentioned graphs has been broken. For this trend to be broken you'd have to have at least as long as has been a rising trend displaying a falling trend. So to bias the issue in your favour let's say that the trend started to be positive in 1995, the point at which the tropo graph I linked to displays a constantly positive anomaly. We are no in 2005 which, I will bet will maintain the trend. So we'll say that to reasonably expect a break in the trend the anomalies should continue to fall until 2015. When the anomalies have displayed a negative trend from now until 2005 then you may have a point.

Yes I have read around the Blog you link to (fallacies per page? - it's full of them), because it's full of specious claptrap such as the above, one year issue, it's not a site I respect. It's as inelegant, poorly considered and frankly unconvincing as CO2Science's "We've found a temperature gauge in Oregon* that shows a reduction in temperature thus the globe cannot be warming" stuff. (*Oregon or wherever it was).

As I say it's Global, not local that counts because the net effect of the additional radiative forcing from CO2 is only viewable on a large scale.

 

[Andre]

fallacies per page? - it's full of them

Perhaps care to give an example?

 

[CobblyWorlds]

Hi again Andre,

No, I don’t intend to waste any more of my time on ClimateAudit. I’d rather discuss the issue at hand.

You started the thread by asserting that

“we.. ..see no troposphere warming in the measured radiosonde data and a distinct lower warming trend in the calculated satellite data:”

and re the strato

“…cooler now than usual albeit without a distinct trend. We see some distinct spikes and a distinct lasting drop between 1993 and 1994, the temperature seems to be slowly recovering again. Not nearly a steady trend inverted proportional to the increase in greenhouse gasses.”

I have produced reference to a graph from the Met Office’s Hadley centre http://www.met-office.gov.uk/resear...r_air_temps.gif which shows, a warming trend in the troposphere and cooling in the stratosphere. I have addressed the disturbance to that trend because of the Mount Pinatubo eruption, June 1991(i.e. accounts for 93/94).

In my post at 8:20 on 19/7/05 I have addressed your unfounded allegation of manipulation of data by the Met office when you said “So, did you discover how those profesionals indeed con us?”.

I have demonstrated that the Hadley Centre graph is consistent with the NOAA graph you posted.

I have also addressed the issue of apparent tropical cooling in the troposphere as seen by radiosonde. http://www.metoffice.com/corporate/.../cv_global.html

So do you accept that there is a distinct warming trend in the troposphere as calculated globally, and again globally, a cooling trend in the stratosphere?

CO2 is predicted by basic physics to reduce stratospheric temperatures. And whereas CFC cooling may account for the high latitude component of the strato trend, tropical CFC concentrations are not high enough to account for the tropical component of the strato trend. So do you accept therefore that, notwithstanding the (theoretically conjectural) issue of ‘upwelling’ in the tropics, it is reasonable, in the light of the lack of an alternate hypothesis to account for the observed warming*, to view the tropical strato cooling as having a significant component attributable to CO2 enhanced greenhouse effect?

*If you or others have such an alternate hypothesis to account for the warming demonstrated by all contemporary means of measuring global temperature. It may be tidiest to start a separate thread to champion that mechanism.

 

[Andre]

So you do not want to substantiate your grave claims. I'm afraid that's not how it works. I happen to know the main author of that site a little bit and I can attest that there is absolutely nothing wrong with his integrity. I demand you to prove otherwise before we can discuss details.

 

[pattylou]

It looks like Cobblyworlds is trying to keep the thread on topic. Maybe you should bring up the ClimateAudit in a separate thread? It might get more focused attention there.

That would also allow interested parties such as myself to understand Cobblyworld's most recent post a bit better, by allowing this thread to remain focused on the most recent points that were raised, which relate *directly* to the original post.

 

[CobblyWorlds]

I don't doubt their integrity. But back in february having spent a while using that site and others (JunkScience sic, and CO2Science). I decided RealClimate displayed less bias, my personal opinion. I concede that in the months since I may have confused the three sites I mention above.

If we were throwing around accusations of grave claims then accusing scientists at the Met Office's Hadley Centre for mispresenting data is equally 'grave'. But then, as I showed their work stands up in spite of what you claimed.

"I demand you to prove otherwise before we can discuss details." Which details, the details of my above post, or of ClimateAudit?

Off now, have a good evening. :)

 

[Andre]

compare the ground station data of theprofessional graph (upper graph heavy black line), with the formal GHCN data and see that they cranked down the ground surface data a few tenth of a degree to hide the current trend. Notice also that the data on my graph remain valid.

http://home.wanadoo.nl/bijkerk/data-manipulation.GIF , GNHC cranked down ~0.1-0.15th degree (red and blue horizontal lines). If I claim something I back it up.

And BTW I did not introduce realclimate here. CW did. Now either withdraw the accusations or back them up.

 

[CobblyWorlds]

1. What's GNHC?

2. Again, in the combination of the 2 plots, you're comparing the Land + Ocean in your graph against the SEA surface record in the Hadley Centre Graph. As is stated here http://www.meto.gov.uk/research/had...a/testfile.html the covering file (last section) for the graph I present, the surface data is a plot of Sea Surface anomalies, extracted from 150W and 90W, 5N and 5S. So you need to compare against the NOAA sea surface part of the 3 graphs you presented here http://lwf.ncdc.noaa.gov/img/climate/research/2005/jun/glob_jun_pg.gif.

Furthermore, the NOAA data is for Global June Mean Temp Anomalies, whereas what I posted is based on seasonal averages with a 3 month running mean. i.e. The Hadley Centre graph I presented is year round, yet the one you link to is for June alone!

So on 2 counts the graphs are not directly comparable to such a degree that you could claim "GNHC cranked down ~0.1-0.15th degree (red and blue horizontal lines)."

However all 5 graphs bear out my assertion of a warming trend, and Hadley Centre graph shows a cooling of the stratosphere.

Can you tell me why I am wrong in my assertion that the global average temperature of both troposphere and surface is increasing when measured by ALL available means, yet the global stratospheric temperature is decreasing?

Patty, or any other readers, please feel free to ask questions and I'll try to make issues more clear, sorry, if it's getting rather technical. But I feel that this IS an important point.

 

[Garlic Bread?]

Isn't it true that the stratosphere is cooling because of ozone - not as a result of global warming?

Isn't it also true that the Uni of Ala-Hunt's Christy adequately shows that the troposphere isn't warming (enough) - and that he tried Quang's methods but disregarded them as poor science because it means bringing in a layer of stratosphere?

 

[Garlic Bread?]

Cobbly, Andre means GHCN - Global Historical Climatology Network

 

[CobblyWorlds]

GHCN - Thanks Garlic Bread,

CFCs contribute to cooling in the lower stratosphere mainly over the poles, but as far as I'm aware their distribution is not enough in tropical regions to account for the tropical strato component of the cooling.

I don't get your second point about Christy/Fu. Surely you'd need to bring in the strato to consider it. Or is this about Fu's claim that stratospheric cooling had been one of the factors that reduced Christy's original low end calculation of Tropospheric temperature rise?