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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Good morning folks!

Paul and I have both heard from Richaard this morning; he's on the ground in Port au Prince and from what he's seen, the biggest need right now is tents...food is certainly an issue, but tents are in very short supply. Please think about who you know that might be able to help with this need and if you can, do the initial legwork (make the contact) and pass them to either Paul or I. We are currently looking at Army/Navy surplus but any connections you folks mught be able to make for us would be greatly appreciated!
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AOI

AOI

AOI

AOI

Humor in Comments
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting Skyepony:
Taz~ wish you water table was as recovered..

A 996
MB GALE LOW IS CENTERED OVER THE E ATLANTIC NEAR 29N30W.

FORMOSA

here is a sat image to go with it

Member Since: July 15, 2006 Posts: 170 Comments: 53526
600. Skyepony (Mod)
Taz~ wish you water table was as recovered..

A 996
MB GALE LOW IS CENTERED OVER THE E ATLANTIC NEAR 29N30W.

FORMOSA
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this is Unbelievable!!!


WOOOOOOOOW you got too take a look at this what a big big turn a round WOW WOW WOW WOW we went from drought too all most no drought



Unbelievable!!!

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598. Skyepony (Mod)
here's the swirl in the east Atlantic.

(Click on that & zoom in)

hhmm..lighting up the probability map..


phase analysis has had it warm core.

Best windsat in the last day
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Quoting Orcasystems:


KOG, WTH happened to your team last night???
i kinda like the term

they choked on that and alot more latly
Member Since: July 15, 2006 Posts: 170 Comments: 53526
Quoting P451:
I hear ya Atmo. I just don't feel like fighting.

If people are going to be rude there's nothing I can do about it. I got no ego to bruise so I don't need to be 'standing up' for myself if you will. It's just a blog afterall. He makes some good points. I disagree with them and I disagree with the attitude but hey it's not under my control.

Been a rough couple of days in the ole' noggin.

So I'm just gunna step back and let sleeping dogs lie.

Apologies to the blog for being a jerkoff the past few days.



Hey my Friend, Look no Apologies... You can disagree with them, me and anyone else if you choose too. But the fighting does get out of hand sometimes and thats when it is wrong..... If we all stepped back from our Laptops and or Computers just for a moment and breath it might not get out of hand.... Now I will tell you I donot agree with "GW" either but I will not get into a fight about it, and if I'm wrong then I'm wrong..... I am "Man Enough" to say that I'm wrong then I move on..... Over the last few years I have found out that it is just not worth it to argue over something that I or anyone else in here has any control over.... I have "great respect" for a lot of people in here and Dr Masters for what he has done for this Community (weather Underground).... So no "Apologies Needed"

Telford AKA Taco :0)
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. wrong spot
Member Since: October 1, 2007 Posts: 81 Comments: 26511
593. IKE
Another heavy rain maker late this coming week for the gulf-coast on the 12Z GFS.
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Quoting KEEPEROFTHEGATE:
well they didn't win what else is new


They were winning 3-0 and ended up loosing 3-5,
thats just bad.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting Orcasystems:


KOG, WTH happened to your team last night???
well they didn't win what else is new
Member Since: July 15, 2006 Posts: 170 Comments: 53526
Quoting KEEPEROFTHEGATE:
LOOKS LIKE ITS TIME FOR SOME EMPTY SPACE TO BE CREATE


KOG, WTH happened to your team last night???
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Golly, here's an interesting article on why people react the way the do.

If people vote against their own interests, it is not because they do not understand what is in their interest or have not yet had it properly explained to them. They do it because they resent having their interests decided for them by politicians who think they know best. There is nothing voters hate more than having things explained to them as though they were idiots. As the saying goes, in politics, when you are explaining, you are losing.

This article has a different focus, but the GW aspect and loathing for Al Gore seems to follow this line. Of course, this is nothing new. Eons ago when I asked my father why Woody Dumas could be mayor of BR for so long and come across as such a doofus, he explained that voters don't want someone in office who is smarter than they are.
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Quoting AussieStorm:
WOW, interesting article i have found. Very much hope its not true.
Link


Ok, now that is hilarious.. how gullible do they think people are?
Member Since: October 1, 2007 Posts: 81 Comments: 26511
587. Inyo
Why would the US even WANT to take over Haiti? It is poverty stricken and stripped of most of its natural resources? If the US were going to start unjustified wars in search of resources to take, well.... maybe you are on the wrong side of the globe.
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584. LOL -- yes, that's a universal tornado we can all agree on!

Whoops, I mean cyclone. See, I'm still getting weather events confused.
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LOL, Good afternoon, Bordo!
I was actually looking forward to Aussie's joke.
But okay, here's one I had actually pulled up for another WU person's blog (I'm pretty sure you'll recognize the theme)! :)

It's relevant because it takes place at least 50 percent under water (pfft)!



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Quoting AwakeInMaryland:


Yes, please.


Oh yes AIM, please post a joke, you're a real live firecracker :0)!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
comment 557 558 streching the blog posts hidden
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Quoting AussieStorm:
Can i post a joke?


Yes, please.
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Quoting GrtLksQuest:


No! Conspiracy theories are so much more gripping than reality - and unfortunately often pervasive and enduring. How do you prove you didn't do something?


That reminds me of the old "joke" about getting security clearances...
"How often would you say s/he beats the children and/or dog?"
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LOOKS LIKE ITS TIME FOR SOME EMPTY SPACE TO BE CREATE
Member Since: July 15, 2006 Posts: 170 Comments: 53526
Quoting AussieStorm:

do you think this is what happened?


No! Conspiracy theories are so much more gripping than reality - and unfortunately often pervasive and enduring. How do you prove you didn't do something?
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I don't have a bucket list.
Should my bucket list be to make a bucket list?
Oh, what a good idea for my blog sometime.
As long as it's weather-related... :)
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Quoting atmoaggie:

No, P451, I disagree. No, I don't sink it is "all good".

All of a sudden we have 2 noobs show up that are instant professionals at digesting earth science data and telling us about all of the wild changes afoot that they have never seen before. When, as best I can tell, these 2 have never analyzed these data sets in the presence of an El Nino, much less, a winter. One is more tuned to data and the other is all about manufactured fear industry.

One of them does actually try to learn how it all works, though misses badly on the normal effects of El Nino. The other just misses, is more than a little abrasive, at times, and gets off on telling us/you to just let him post CC data and his alarmist claims without challenge?

No. I don't sink it is all good. Otherwise we would need to be preparing for our world to end in the next couple of months and I would need to work exclusively on my bucket list.

Not at all "all good".



I've been adjusting my ignore list accordingly. I don't mind listening to people have civil conversations about the climate, but when you start being totally closed down and uncivil with other people, it's just not right. My personal opinion, and that's just it is my opinion, is that if people feel that strongly about what is going on, they should stop spending time arguing and being harsh to others and try and spend their time being constructive, and putting into practice practical solutions to help our environment.


As for me I believe in taking care of what we've been given and I do what I can. I drive a car with good gas mileage, I try and recycle. I don't use hardly any energy, use my windows when I can, and I try too use my fans if I can without putting the A/C on. Those things make sense to me. They're practical.

Forcing one anothers opinions down each others throats is not. We all share this planet together, might as well at least be civil with each other. I'll leave this with a quote from Mother Teresa:

"If we have no peace, it is because we have forgotten that we belong to each other."
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Quoting atmoaggie:

Otherwise we would need to be preparing for our world to end in the next couple of months and I would need to work exclusively on my bucket list.

Not at all "all good".
No, you are not alarmist.
Please elaborate more on your plans. And btw i'm longer active than you at WU - so much for the noob.
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Quoting P451:
It's all good.

No, P451, I disagree. No, I don't sink it is "all good".

All of a sudden we have 2 noobs show up that are instant professionals at digesting earth science data and telling us about all of the wild changes afoot that they have never seen before. When, as best I can tell, these 2 have never analyzed these data sets in the presence of an El Nino, much less, a winter. One is more tuned to data and the other is all about manufactured fear industry.

One of them does actually try to learn how it all works, though misses badly on the normal effects of El Nino. The other just misses, is more than a little abrasive, at times, and gets off on telling us/you to just let him post CC data and his alarmist claims without challenge?

No. I don't sink it is all good. Otherwise we would need to be preparing for our world to end in the next couple of months and I would need to work exclusively on my bucket list.

Not at all "all good".
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Quoting drg0dOwnCountry:
Ops, meant to respond to 562.

maybe you should check which post you are replying too.
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Quoting GrtLksQuest:


We can't predict earthquakes but we can cause them?

do you think this is what happened?
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Quoting AussieStorm:

why did u post that video, it doesn't relate to the quake in anyway.
Ops, meant to respond to 562.
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Quoting P451:
Wow, interesting. I was on a flight that got struck by lightning. Damndest thing I ever saw. It's pretty insane to see a lightning bolt about a foot from your face but I did see it.

Last week or so i read about 2 airplane crashes and if i remember correct. Everytime they contributed it to severe weather ...
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Quoting drg0dOwnCountry:


why did u post that video, it doesn't relate to the quake in anyway.
Member Since: September 30, 2007 Posts: 9 Comments: 15935
Quoting AussieStorm:
WOW, interesting article i have found. Very much hope its not true.
Link

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Can i post a joke?
Member Since: September 30, 2007 Posts: 9 Comments: 15935
564. unf97
Good morning to all of my fellow WU bloggers!

It is a morning you would expect for the last day of January, a bit chilly and nippy in Jax area. Currently, skies are cloudy and the temp is 42.7 degrees at 9:15 a.m. At my north Jax location. The morning low was 39.6 degrees.

The ice ans snow storm that moved through the Southern Plains, Tennessee Valley and Mid Atlantic states during the past 36 hours has left a very decent snow pack in those areas. The result is the shallow polar air mass has been slower to modify. This has also kept a large area of cold low level status deck of clouds over the SE US, which has been very slow to erode. Eventually, subsidence will erode these clouds as the day progresses. These clouds will help keep the temps from rising much today. We will be lucky to make it to 50 degrees, especially if clearing doesn't occur until late.

Another wet week ahead for the Florida peninsula as the active EL Nino pattern continues. It appears that the models are forecasting two Low pressure areas to move out of the GOM, with both systems appearing to track farther south. The first Low is projected to move over Central FL Tuesday. The other GOM Low is forecast to move through during the Thursday-Friday period. The second system later this week appears to be the stronger one glancing at the models.

Just a cool and wet week ahead of NE FL. Thankfully, it appears that we won't see any arctic air intrusions at least for the next week.

Have a great day everyone.
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Here is an interesting article for those who are interested in understanding why some folks get so emotional about ecological issues, including CC:

Link
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Quoting AussieStorm:
WOW, interesting article i have found. Very much hope its not true.
Link


We can't predict earthquakes but we can cause them?
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Quoting AussieStorm:
WOW, interesting article i have found. Very much hope its not true.
Link


Conspiracy theories really are fun, aren't they? I still enjoy reading about whether we really landed on the moon. Of course, we did but it is still fun to read.
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WOW, interesting article i have found. Very much hope its not true.
Link
Member Since: September 30, 2007 Posts: 9 Comments: 15935


Phytoplankton bloom in the southern Pacific Ocean, off Chile

__________________________________________________________________________________________________
Could this be cause by the high SST's?
Member Since: September 30, 2007 Posts: 9 Comments: 15935
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Quoting Patrap:
Recent Greenland ice loss responsible for one sixth of sea-level rise
I belive what many do not know yet is the fact that warmer temperature also increases sea level rise.


Attaining maximum density


Almost all known substances undergo thermal expansion in response to heating, meaning that a given mass of substance contracts to a low volume at low temperatures, when little thermal energy is present. Substances, especially fluids in which intermolecular forces are weak, also undergo compression upon the application of pressure. Nearly all substances therefore reach a density maximum at very low temperatures and very high pressures, characteristic properties of the solid state of matter.

Maximum density of water

An especially notable irregular maximum density is that of water, which reaches a density peak at 3.98 °C under standard conditions of pressure due to the low-density crystal structure of typical ice. This has important ramifications in Earth's ecosystem; see Water (molecule)#Density of water and ice.

http://en.wikipedia.org/wiki/Maximum_density_of_water

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Quoting P451:


Is your word science?

Is your opinion science?

I think not.

You're close minded which is a shame. Seems to be the same for all AGW theorists however. Your opinion is fact and you don't want to hear what anyone else has to say.

Just seems to be the norm. Not sure why.


I base my argument on news and yes scientific evidence. If you don't than well - just don't. However this is a weather and climate blog and i acknowledge your post on weather, i mean it. But if you post things which contradict science evidence than you need to provide - scientific evidence.
I suggest you stay with weather reports and let me post my climate stuff. Cheers.
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Quoting tornadodude:
wow, definitely was a slow night in here! have a great one everyone! (:
I been out to party ;) Which btw was quiet a task as almost all the streets and sidewalks are completly iced.
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About

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