Stratospheric water vapor decline credited with slowing global warming

By: Dr. Jeff Masters , 6:18 PM GMT on January 29, 2010

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After a steep rise in global average temperatures in the 1990s, the 2000s have seen relatively flat temperatures, despite increasing levels of CO2 emissions by humans. This reduced warming may be partially due to a sharp decrease in stratospheric water vapor that began after 2000, according to research published yesterday in Science by a team of researchers led by Dr. Susan Solomon of NOAA's Earth System Research Laboratory in Boulder. Water vapor is a potent greenhouse gas capable of significantly warming the planet, and its potency is much higher when it is located in the lower stratosphere where temperatures are extremely cold. Greenhouse gases located in cold regions of the atmosphere are more effective at heating the planet because they absorb heat radiation from the Earth's relatively warm surface, but then re-emit energy at a much colder temperature, resulting in less heat energy lost to space. Even though stratospheric water vapor can exist at concentrations more than 100 times lower than at the surface, the 10% drop in stratospheric water vapor since 2000 noted by Solomon et al. acted to slow down global warming by 25% between 2000 - 2009, compared to that which would have occurred due only to carbon dioxide and other greenhouse gases.


Figure 1. Stratospheric water vapor in the tropics, between 5°S - 5°N, as measured by the HALOE instrument on the Upper Atmosphere Research Satellite (UARS), between 1993 - 2005. The bottom portion of the plot shows the lower stratosphere, just above where tall thunderstorms are able to transport water vapor into the stratosphere. A strong yearly cycle is evident in the water vapor, due to the seasonal variation in heavy thunderstorms over the tropics. Once in the lower stratosphere, the waver vapor takes about 1.2 years to travel to the upper stratosphere, as seen in the bending of the contours to the right with height. Note that beginning in 2001, very low water vapor concentrations less than 2.2 parts per million by volume (ppmv) began appearing in the lower stratosphere, due to substantial cooling. Image credit: Rosenlof, K. H., and G. C. Reid (2008), Trends in the temperature and water vapor content of the tropical lower stratosphere: Sea surface connection, J. Geophys. Res., 113, D06107, doi:10.1029/2007JD009109.

The observations
We haven't been able to observe water vapor in the stratosphere very long--accurate global measurements only go back to 1991, when the HALOE instrument aboard the Upper Atmosphere Research Satellite (UARS) began taking data (Figure 1). Stratospheric water vapor showed an increase of about 0.5 parts per million by volume (ppmv) during the 1990s. But after 2000, a sudden drop of 0.4 ppmv was observed, and this decrease has persisted into 2009. To see how these changes impacted the amount of global warming, Solomon et al. fed the observations into a specialized high-resolution model that computed the change in heat from the fluctuating water vapor levels. They found that the increase in stratospheric water vapor in the 1990s led to about a 30% increase in the amount of global warming observed during that decade, and the decrease of 0.4 ppmv since 2000 led to a 25% reduction between 2000 - 2009.

How water vapor gets into the stratosphere
The stratosphere has two main sources of water vapor: transport from the lower atmosphere (the troposphere) via tall thunderstorms, and the chemical breakdown of methane gas into water vapor and carbon dioxide. With regard to greenhouse effect warming, transport of water vapor by thunderstorms is the most important source, since this mechanism delivers water vapor to the lowest part of the stratosphere, where temperatures are coldest and greenhouse gases are more effective at warming the climate. There is a limit as to how much water vapor that can enter the stratosphere via thunderstorms, though. Temperature decreases with altitude from the surface to the bottom of the stratosphere, where they begin to rise with height due to the solar energy-absorbing effect of the stratospheric ozone layer. As moisture-laden air rises in thunderstorms towards the lower stratosphere, it encounters the atmosphere's "cold point"--the coldest point in the lower atmosphere, at the base of the stratosphere. Since the amount of water vapor that can be present in the atmosphere decreases as the temperature gets colder, and moisture being transported to the stratosphere must traverse through the "cold point" of the atmosphere, the air gets "freeze dried" and loses most of its moisture.


Figure 2. The departure from average of tropopause temperature (dark line) and Sea Surface Temperature (light dashed line) for the tropical Pacific Ocean between 10°S - 10°N, from 1981 - 2007. The tropopause is the bottom boundary of the stratosphere. The SST data is for 139°W - 171°W longitude, and is from the NOAA Optimal Interpolation v2 data set. The tropopause data is from balloon soundings, for the region 171°W - 200°W. The SST is plotted so that the anomalies increase as one looks down. Note that prior to about 2000, tropopause temperatures and SSTs increased and decreased together, but that beginning in 2000 - 2001, a sharp climate shift occurred, and the two quantities became anti-correlated. The sudden drop in tropopause temperature in 2000 - 2001 caused a sharp drop in stratospheric water vapor. Image credit: Rosenlof, K. H., and G. C. Reid (2008), Trends in the temperature and water vapor content of the tropical lower stratosphere: Sea surface connection, J. Geophys. Res., 113, D06107, doi:10.1029/2007JD009109.

Why did stratospheric water vapor drop in 2000?
Tall thunderstorms capable of delivering water vapor into the stratosphere occur primarily in the tropics, particularly over the Western Pacific, where a huge warm pool with very high Sea Surface Temperatures (SSTs) exists. In 2000, this region experienced a sharp increase in SST of 0.25°C, which has remained consistent though the 2000s (Figure 2). Coincident with this increase in SST came a sharp drop in the "cold point" temperature of the tropopause--the lower boundary of the stratosphere. This reduction in "cold point" temperature meant that less water vapor could make it into the stratosphere over the Tropical Pacific, since more thunderstorm water was getting "freeze dried" out. Did global warming trigger this increase in Pacific SST, resulting in cooling of the "cold point" and less water vapor in the stratosphere? Or was it random variation due to some decades-long natural cycle? This key question was left unanswered by the Solomon et al. study, and observations of stratospheric water vapor don't go back far enough to offer a reasonable guess. One factor arguing against global warming having triggered a negative feedback of this nature is that prior to 2000, increases in Western Pacific SST caused increases in "cold point" temperatures--behavior opposite of what has been seen since 2000.

If global warming has triggered the decrease in stratospheric water vapor seen since 2000, it could mean that the climate models have predicted too much global warming, since they don't predict that such a negative feedback exists. On the other hand, if this is a natural cycle, we can expect the recent flattening in global temperatures to average out in the long run, with a return to steeper increases in temperature in the coming decades. Climate models currently do a poor job modeling the complex dynamics of water vapor in the stratosphere, and are not much help figuring out what's going on. Complicating the issue is the fact that about 15% of all thunderstorms capable of delivering water vapor into the stratosphere are generated by tropical cyclones (Rosenlof and Reid, 2008), and tropical cyclones are not well-treated by climate models. We also have to factor in the impact of stratospheric ozone loss, which acts to cool the lower stratosphere. This effect should gradually decrease in future decades as CFC levels decline, though. The stratosphere is a devilishly complicated place that can have a significant impact on global climate change, and we are many years from understanding what is going on there.

References
Romps, D.M., and Z. Kuang, "Overshooting convection in tropical cyclones", Geophysical Research Letters, 2009; 36 (9): L09804 DOI: 10.1029/2009GL037396

Rosenlof, K. H., and G. C. Reid (2008), Trends in the temperature and water vapor content of the tropical lower stratosphere: Sea surface connection, J. Geophys. Res., 113, D06107, doi:10.1029/2007JD009109.

Portlight Haiti update
Paul Timmons, who directs the Portlight.org disaster-relief charity that has sprung up from the hard work and dedication of many members of the wunderground.com community, was interviewed by NBC yesterday. The reporter doing the story is planning to follow the Portlight-donated goods to Haiti and interview the people with disabilities that receive the donations. It is uncertain when the story will be aired, but I'll try to give everyone a heads-up.

Next post
My next post will probably be Tuesday (Groundhog's Day), when I plan to discuss Phil's forecast for the rest of winter. I'll throw in my two cents worth, too.

Jeff Masters

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Quoting Ossqss:


How about this one? LoL

pneumonoultramicroscopicsilicovolcanoconiosis

BTW, I think this is the official longest word in an English dictionary. Don't ask how I know that :)


I prefer supercalifragilisticexpialidocious, which of course backwards is dociousaliexpilisticfragicalirupus. But said too loud it makes you sound precocious. :)
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Quoting KEEPEROFTHEGATE:
give it a rest already will ya
Ok, but consider what you post too. Have a nice weekend.
Member Since: September 22, 2005 Posts: 11 Comments: 2032
Quoting Ossqss:


How about this one? LoL

pneumonoultramicroscopicsilicovolcanoconiosis

BTW, I think this is the official longest word in an English dictionary. Don't ask how I know that :)


Don't forget about:

Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch - place in Wales

Taumatawhakatangihangakoauauotamateapokaiwhenuakitanatahu - hill in New Zealand, had to copypaste that one

nordostersjokustartilleriflygspanningssimulatoranlaggningsmaterielunderhallsuppfoljningssystemdisku ssionssionssinlaggsforberedelsearbeten - check the Guiness Book of World Records 2006.
Member Since: August 30, 2008 Posts: 8 Comments: 2834
the UN is not in any way a government...it's an alliance of governments...
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Quoting pottery:
484. Interesting quote from Mrnick there.
But, why would 'global government' (whatever that may be), be worse than what we have now?


Hey Pottery.

You have witnessed the UN, no?

Just a few Human Rights Commission member states for illustration:

- Sudan
- China
- Nigeria
- Saudi Arabia

No thanks. ;)
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Quoting AwakeInMaryland:


I still don't know what it means, but here it is:

Probabilistic method
From Wikipedia, the free encyclopedia
Link
This article is not about interactive proof systems which use probability to convince a verifier that a proof is correct, nor about probabilistic algorithms, which give the right answer with high probability but not with certainty, nor about Monte Carlo methods, which are simulations relying on pseudo-randomness.

The probabilistic method is a nonconstructive method, primarily used in combinatorics and pioneered by Paul Erdős, for proving the existence of a prescribed kind of mathematical object. It works by showing that if one randomly chooses objects from a specified class, the probability that the result is of the prescribed kind is more than zero. Although the proof uses probability, the final conclusion is determined for certain, without any possible error.

This method has now been applied to other areas of mathematics such as number theory, linear algebra, and real analysis.
--------------------------------------------------
And I'm pretty sure if it's on Wikipedia Pottery can slip ballistic in there somewhere.


Don't forget Wiktionary: Link
Member Since: August 30, 2008 Posts: 8 Comments: 2834
Good post Astro. 492.
But you are ignoring the fact that some of us ( I exclude myself, you, and others) cannot deal with Reality. It is worrisome and scary. Better to wallow in the status quo, and hope it all turns out all right.
'The Victims of Comfort'. By Keb Mo. U- Tube it if you can listen to good Blues music.
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Quoting AussieStorm:
Can anyone guess where ex-TC Olga is?



Wow. It's going to drift into New Zealand and then Antartica!
Member Since: August 30, 2008 Posts: 8 Comments: 2834
Quoting Patrap:


The recent cold air has been creating a gap of cold SSTs at the coast.
Member Since: August 30, 2008 Posts: 8 Comments: 2834
489. Indeed! And it would be a joy to see if anyone can come up with a meaningful answer.
I am not holding my breath...
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484 JFLORIDA:

Not quite, but the feet daggers and deniers manage to use it as a "good" argument to keep ultimately required advancement in green tech and production at bay:




Ya think?

UN Agenda 21 - Coming to a Neighborhood near You

http://www.un.org/esa/dsd/agenda21/index.shtml Core Publications
Agenda 21


Have a good evening - out
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445, 446:

Business-as-usual cannot continue much longer, for our own success as a species may prove to be our own downfall. Although some people are advocates for continuous, indefinite growth, that simply is not possible because resources are finite and we need to conserve what we have.

Although science is changing, and predictions about the future are somewhat speculative in nature, climate again is about averages. What computer models predict are a coarse smoothing of the averages, and the actual averages themsleves could turn out to be more extreme and erratic, while the extremes will be...extremely extreme. The departure from the current climate state could incite more extremes, then the rate that the extremes are intensifying would speed up. There is a great deal of uncertainty, but when we learn more about the subject we should add this new information to climate models, not try to disprove the science altogether. Constantly trying to disprove a theory without trying to add onto it is not science.

If you keep saying "we can't", we can't. If you say we can then we can. Opinions are influenced by what we want to believe, not what nessecarily is true, and not wanting to listen to the other side is both censorship and denial.

Not caring about the future is a terrible thing to do, even to yourself. We cannot keep living as a society that is morally detached from its surroundings, as this "shell" will inevitably break.

Global warming in the short-term doesn't mean we're going to die. It simply means that we will be affected by it in our daily lives, although it will always be difficult to ascertain what specific events are caused or influenced by global warming. These effects may be extreme, or benign, but maybe it's possible to look at events before they happen by making specific predictions which is difficult to do. "Listening to no-one but themselves" is what the climate deniers are doing. How ironic that this kind of argument is used by both sides.

Whether or not something is an "attack" might depend on how you look at it if it is not blatant.
Member Since: August 30, 2008 Posts: 8 Comments: 2834
Have a great weekend, Awake.
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Quoting pottery:
484. Interesting quote from Mrnick there.
But, why would 'global government' (whatever that may be), be worse than what we have now?


Instigator, lol!
Just popped in for a little bit;
good to see you Pottery, bye all for now.
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting pottery:
484. Interesting quote from Mrnick there.
But, why would 'global government' (whatever that may be), be worse than what we have now?


and THAT, boys and girls, is the $64,000 question...
Member Since: Posts: Comments:
484. Interesting quote from Mrnick there.
But, why would 'global government' (whatever that may be), be worse than what we have now?
Member Since: Posts: Comments:
"Urban Heat Island Effect" -- couldn't think of that earlier today, when trading posts with Taz...

White Roofs Could Reduce Urban Heating
LiveScience Staff
livescience.com Sat Jan 30, 10:25 am ET

To help combat global warming and urban heating, we might just need to paint the town white.

A new modeling study simulated the effects of painting roofs white to reflect incoming solar rays and found that it could help cool cities and reduce the effects of global warming.

The feasibility of such an initiative for cities remains to be seen, researchers caution, but the idea has been backed by U.S. Energy Secretary Steven Chu and other policymakers. And now there's some science behind the political support.

"Our research demonstrates that white roofs, at least in theory, can be an effective method for reducing urban heat," said Keith Oleson, the lead author of the study and a researcher at the National Center for Atmospheric Research (NCAR) in Boulder, Colo. "It remains to be seen if it's actually feasible for cities to paint their roofs white, but the idea certainly warrants further investigation."

Cities are particularly vulnerable to climate change because of a phenomenon known as the urban heat island effect. The asphalt roads, tar roofs and other artificial surfaces that permeate cities absorb heat from the sun, making temperatures in urban areas on average 2 to 5 degrees Fahrenheit (1 to 3 degrees Celsius) higher than in rural areas.
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Slow night huh lol
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Quoting WunderFul:
All of this climate change bickering is great fun, but regardless of your stance on the issue, if you've got clear skies right now, look east -- full moon with a very bright Mars directly above it. We are actually quite small and insignificant when you think about it.


Yes, thanks for that. If you have a telescope, look for the Beehive cluster above Mars. We all share the same sky, so not to create excess pollution and global warming.
Member Since: August 30, 2008 Posts: 8 Comments: 2834
heheheheheh
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Quoting pottery:
472, I agree.
But surely, you ought not to let it bother you so.
I mean, what if someone came up to you and whispered 'dynamism' in your ear?


I'd probably marry her...
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Quoting pottery:
472, I agree.
But surely, you ought not to let it bother you so.
I mean, what if someone came up to you and whispered 'dynamism' in your ear?

Promise?
Member Since: August 19, 2008 Posts: 32 Comments: 1918
472, I agree.
But surely, you ought not to let it bother you so.
I mean, what if someone came up to you and whispered 'dynamism' in your ear?
Member Since: Posts: Comments:
475...wow....a word should have vowels...
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Quoting presslord:
well...maybe it's a word, then...but...it's a stupid word...


Oh, it gets worse:

See also

* Probabilistic proofs of non-probabilistic theorems

I'm pretty sure AtmoAggie and Grothar colluded on this together as a practical joke...
Member Since: August 19, 2008 Posts: 32 Comments: 1918
actually...my wife made shrimp and grits...which is a Charlesston tradition...and is much better than it sounds
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Quoting drg0dOwnCountry:
This is your personal opinion which has absolutly nothing todo with the reality and contradicts the overwhelming evidence of sciene. You should know better as the facts are posted here over and over again, still you are to ignorant to accept those. You will start to worry soon, because your earlyer argument that we will not see any significant effects (which already massive) become more pronounced every day. Already there are western nations, which struggle with national security, distribution of energy, distribution of food/water and rising cost from damage of accelerating climate change effects. Imagine the situation you go to the supermakret and cannot afford or buy bread and milk. This happend this winter already in the UK.
give it a rest already will ya
Member Since: July 15, 2006 Posts: 163 Comments: 52173
Quoting presslord:
well...maybe it's a word, then...but...it's a stupid word...


How about this one? LoL

pneumonoultramicroscopicsilicovolcanoconiosis

BTW, I think this is the official longest word in an English dictionary. Don't ask how I know that :)
Member Since: Posts: Comments:
Quoting P451:


I think ... but we won't know.

Why? Because you can't predict climate based off of the 150 years of known records....

This is your personal opinion which has absolutly nothing todo with the reality and contradicts the overwhelming evidence of sciene. You should know better as the facts are posted here over and over again, still you are to ignorant to accept those. You will start to worry soon, because your earlyer argument that we will not see any significant effects (which already massive) become more pronounced every day. Already there are western nations, which struggle with national security, distribution of energy, distribution of food/water and rising cost from damage of accelerating climate change effects. Imagine the situation you go to the supermakret and cannot afford or buy bread and milk. This happend this winter already in the UK.
Member Since: September 22, 2005 Posts: 11 Comments: 2032
Quoting presslord:
I just had a blueberry PopTart...Does that count?
sure have two more
Member Since: July 15, 2006 Posts: 163 Comments: 52173
well...maybe it's a word, then...but...it's a stupid word...
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463, Ah!
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Aussie...It's a good idea...he may have talked with Flood...I'll follow up...thanks...
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Quoting presslord:
'Probabalistic' is simply not a word...
Quoting pottery:
"probabalistic" means probably ballistic. Or it should, anyway. I think.


I still don't know what it means, but here it is:

Probabilistic method
From Wikipedia, the free encyclopedia
Link
This article is not about interactive proof systems which use probability to convince a verifier that a proof is correct, nor about probabilistic algorithms, which give the right answer with high probability but not with certainty, nor about Monte Carlo methods, which are simulations relying on pseudo-randomness.

The probabilistic method is a nonconstructive method, primarily used in combinatorics and pioneered by Paul Erdős, for proving the existence of a prescribed kind of mathematical object. It works by showing that if one randomly chooses objects from a specified class, the probability that the result is of the prescribed kind is more than zero. Although the proof uses probability, the final conclusion is determined for certain, without any possible error.

This method has now been applied to other areas of mathematics such as number theory, linear algebra, and real analysis.
--------------------------------------------------
And I'm pretty sure if it's on Wikipedia Pottery can slip ballistic in there somewhere.
Member Since: August 19, 2008 Posts: 32 Comments: 1918
I just had a blueberry PopTart...Does that count?
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Quoting presslord:
KOG and pott...all is well...hope y'all are OK

Hey press, Has Bob gotten in touch with you or Floodman about putting an AD together about Portlight and what ya do and how people can help, to be broadcast over the WRBN network. It was just a thought i shared with him on Friday.
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Good one Babbit.

Hi Keeper. Glad to say we got nearly an inch of rain the last 2 days. It's the Moon, you know.
But yeah, it is looking like a long, dry, season ahead. The Resevoirs are low, because Nov. and Dec. only produced 1/3 of average rainfall.
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you been eating press need food to keep going and i know your going
Member Since: July 15, 2006 Posts: 163 Comments: 52173
Can anyone guess where ex-TC Olga is?

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post 451
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KOG and pott...all is well...hope y'all are OK
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...and anyway, where on Earth did you find such a word?
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hello pottery hows your winter been dry i know
Member Since: July 15, 2006 Posts: 163 Comments: 52173
Quoting mrnicktou:
AGW is only there so they can try to push a global government on us and its happening.
See this is your opinion, which btw has nothing todo with science or reality. If we argue on such assumption, i could say that you work for a fossil fuel company which spreads doubt about AGW by refusing to accept empirical data, to prevent regulation and phase out of fossil fuels.
Member Since: September 22, 2005 Posts: 11 Comments: 2032
Main Entry: prob·a·bi·lis·tic
Pronunciation: \ˌprä-bə-bə-ˈlis-tik\
Function: adjective
Date: 1864

1 : of or relating to probabilism
2 : of, relating to, or based on probability


That's Merriam-Webster.
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"probabalistic" means probably ballistic. Or it should, anyway. I think.
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Quoting presslord:
'Probabalistic' is simply not a word...
hello press how ya keeping
Member Since: July 15, 2006 Posts: 163 Comments: 52173
'Probabalistic' is simply not a word...
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AGW is only there so they can try to push a global government on us and its happening.
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A bit off topic (if that is OK?), but interesting from yesterday :)

Dinosaur Discovery Helps Solve Piece of Evolutionary Puzzle
ScienceDaily (Jan. 29, 2010)
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About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.