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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Is the climate sensitivity to ozone perturbations enhanced by stratospheric water vapor feedback?
The climate response to a set of idealized ozone perturbations is investigated by integrations with a coupled atmosphere‐ocean model. Although all perturbations, including a homogeneous CO2 increase, induce the same stratosphere adjusted, tropopause radiative forcing, the climate response is quite variable within the set of experiments. Except for an upper tropospheric ozone increase, our model is more sensitive to ozone perturbations than to an equivalent CO2 perturbation. This applies in particular to a lower stratospheric ozone increase. The accompanying changes in the stratospheric water vapor (SWV) distribution are found to impose additional forcings on climate that may well exceed the forcings due to the original perturbations. Without SWV feedback on radiation the climate sensitivity to a lower stratospheric ozone increase draws remarkably near the respective value for equivalent CO2. This emphasizes the crucial role SWV may have in the forcing‐response relationship.
http://www.agu.org/pubs/crossref/2001/2001GL013000.shtml
Member Since: September 22, 2005 Posts: 11 Comments: 2032
Quoting GeoffreyWPB:
Is my cable going out or are they bleeping this guy singing now?

No your cable is fine they Bleeped him out and with all due respect they could have done the show with out that song....

Taco :0)
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Wow...I didn't know "England Dan" passed away last year...One of my favorite songs:

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Quoting GeoffreyWPB:
Is my cable going out or are they bleeping this guy singing now?


LOL! With Eminem...bleeping is a good bet.

I had the breaks, too...could be bad audio signal...or not.
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Is my cable going out or are they bleeping this guy singing now?
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Quoting GeoffreyWPB:
Although the Elton John and Lady Gaga opening gave me the creeps.


The predictably unpredictable Lady Gaga arrived looking like a space-age Tinkerbell with sunflower-yellow, shoulder-length locks. In her right hand Gaga held a giant, chrome-spiked star. She wore an Armani-designed sheer, pink dress ringed with Saturn-like circles.

(Does Astronomy count as weather-related?)

Geoff -- "Dump-Cake"? That could get you banned!

Really, easy to make is good!
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Aussie Storm -- that is a great story! Thanks for the laugh.

I've been posting every day or two about the earthquake swarm in Yellowstone -- well, today, the New York Times decided to take a look at what is going on there:

http://www.nytimes.com/2010/02/01/science/01yellowstone.html

Of interest, earlier today, a 2.9 earthquake hit about 30 miles east of the area where the vast majority of quakes have been hitting. This swarm is now the second largest on record in terms of numbers of quakes reported since 1/17 in Yellowstone.
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I will...called a "Dump Cake". Really easy to make.
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Although the Elton John and Lady Gaga opening gave me the creeps.
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Quoting GeoffreyWPB:
Is Grothar out of the Country again?


I got a brief message last week that he was home, but he's been really busy since he speaks so many languages, including the Haitian Creole. He could be anywhere, FL, DC, NY...

Oh, and have you seen the age of music producers?
Sorry, we're old!

ADD: Got your message. Did you send a recipe?
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Watching the Grammy's tonight...Guess I'm not that old...Know most of the songs and winners.
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Is Grothar out of the Country again?
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Funny Aussie. ROFLMAO.
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AUSSIE! ROFLMAO! That joke was actually worth waiting all day and evening for!

The moral of the story is....being concerned about public opinion can bring you much grief and misery...and even shorten your life. So be yourself and enjoy life...
Stop worrying about everyone else's ass and you'll be a lot happier and live longer!


And I give you an "AMEN" on that!

Thanks for the perfect end to this day!
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting tornadodude:


link ;)


OUch.... I knew I should not have looked! Back at ya!

With a disclaimer - LoL

Link :)

Note: please see the properties of the picture before you file suit. It's only fair :)
Member Since: June 12, 2005 Posts: 6 Comments: 8186
Skye - I like that. Thanks.
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Quoting presslord:
Anybody got a shower curtain I can hide behind?

just wondering why you want to be behind a shower curtain..... Do you have something to "hide"????

Taco :0)
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Quoting AwakeInMaryland:


Yes, please.


Pastor Humor

The pastor entered his donkey in a race and it won. The pastor was so
pleased with the donkey that he entered it in the race again, and it won
again The local paper read:

PASTOR'S ASS OUT FRONT

The Bishop was so upset with this kind of publicity that he ordered the
pastor not to
enter the donkey in another race. The next day, the local paper headline
read:

BISHOP SCRATCHES PASTOR'S ASS

This was too much for the bishop; so he ordered the pastor to get rid of
the
donkey. The pastor decided to give it to a nun in a nearby convent. The
local paper, hearing of the
news, posted the following headline the next day:

NUN HAS BEST ASS IN TOWN

The bishop fainted. He informed the nun that she would have to get rid of
the donkey, so she sold it to a farmer for $10.The next day the paper read:

NUN SELLS ASS FOR $10

This was too much for the bishop, so he ordered the nun to buy back the
donkey and lead it to the plains where it could run wild. The next day the
headlines read:

NUN ANNOUNCES HER ASS IS WILD AND FREE

The bishop was buried the next day. The moral of the story is....being
concerned about public opinion can bring you much grief and misery...and
even shorten your life. So be yourself and enjoy life...
Stop worrying about everyone else's ass and you'll be a lot happier and live
longer!
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Quoting tornadodude:


link ;)


Whose that, Matt?
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734. Skyepony (Mod)
Shaun & Tim are going to start doing a live WeatherUnderground internet radio show..
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Quoting ycd0108:
Well somebody thinks this "climate change" stuff bears watching:
The Pentagon will for the first time rank global warming as a destabilising force, adding fuel to conflict and putting US troops at risk around the world, in a major strategy review to be presented to Congress tomorrow. The quadrennial defence review, prepared by the Pentagon to update Congress on its security vision, will direct military planners to keep track of the latest climate science, and to factor global warming into their long term strategic planning.
From the U.K. Guardian


It does bear watching, without a doubt.
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Just throwing this out there as it is slow.

If an ice age is coming, be it 2K or 4K years from now, maybe the plan is to warm as much as possible to extend that.

The history of the earth, to our knowledge, shows clearly that life flourishes between ice ages and struggles tremendously during.

While ice ages have, in fact, been very inhospitable to life, all recorded warm periods (and, yes, including hotter than today and hotter than the worse case scenario predictions) have been teeming with life.

Do you know the grand plan? I don't.
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Well somebody thinks this "climate change" stuff bears watching:
The Pentagon will for the first time rank global warming as a destabilising force, adding fuel to conflict and putting US troops at risk around the world, in a major strategy review to be presented to Congress tomorrow. The quadrennial defence review, prepared by the Pentagon to update Congress on its security vision, will direct military planners to keep track of the latest climate science, and to factor global warming into their long term strategic planning.
From the U.K. Guardian
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Quoting Seastep:


LOL. Thanks again for the chuckle.

Still chuckling as I type.


link ;)
Member Since: June 28, 2006 Posts: 25 Comments: 8357
Quoting presslord:
Anybody got a shower curtain I can hide behind?


LOL. Thanks again for the chuckle.

Still chuckling as I type.
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Quoting Floridano:


Excuse me? :0.


I said ANYBODY GOT A SHOWER CURTAIN I CAN HIDE BEHIND!!
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Quoting presslord:
Anybody got a shower curtain I can hide behind?


Excuse me? :0.
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Anybody got a shower curtain I can hide behind?
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Howdy, Mr. Paul Timmons.
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Night Matt and thank you! (:
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723. Skyepony (Mod)
Looking at satellite data...I'd say easy bet..This month we just had goes down as hottest January recorded yet..



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well I'm off to do some homework, have a goodnight everyone! spread the word!
Member Since: June 28, 2006 Posts: 25 Comments: 8357
Quoting drg0dOwnCountry:
Uh, i have to regret im not so much into sports (beside running). Been to a san diego padres game once - which was quiet cool.



yup....just flip a coin...pick a team...and you're in...

and, just to help you out...it's really a matter of the Saints...or...well...nobody else...
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Edit: Ooops, wrong window/blog!

ROCK ON, PORTLIGHT!!!!!!
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It's for a good cause Country and you have a 50-50 chance. It's $10 which would help out a lot.
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Quoting GeoffreyWPB:
Country...go to Matt's blog and make your Super Bowl prediction. Come on, you have posted quite a bit on here and have been a member for quite a while.
Uh, i have to regret im not so much into sports (beside running). Been to a san diego padres game once - which was quiet cool.
Member Since: September 22, 2005 Posts: 11 Comments: 2032
Country...go to Matt's blog and make your Super Bowl prediction. Come on, you have posted quite a bit on here and have been a member for quite a while.
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Quoting drg0dOwnCountry:
Im very happy with my shares in solar ;)


Great!
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Quoting drg0dOwnCountry:
Renewable energy is helping China complete its economic transformation and achieve "energy security". China rapidly has moved along the path of renewable energy development.[1] About 16 percent of China's electricity came from renewable sources in 2006, led by the world's largest number of hydroelectric generators.[2] Total installations of hydropower reached 145,000 MW in 2007. China has set a target of 190,000 MW for 2010.[3] Technology development and increased amounts of investment in renewable energy technologies and installations has increased markedly throughout the 2000s in China, and investment in renewables is now part of China's economic stimulus strategy.[4] Researchers from Harvard University and Tsinghua University have found that China could meet all of their electricity demands from wind power through 2030
http://en.wikipedia.org/wiki/Renewable_energy_in_China


Hope it works out for them.
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714. xcool
lmao
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Quoting Seastep:


Maybe this can be a new arms war, ala Reagan, except we save and they spend. Win win for the US.

It's a bet, and no less, right now.

I put my money on mother nature.
Im very happy with my shares in solar ;)
Member Since: September 22, 2005 Posts: 11 Comments: 2032
Quoting LongStrangeTrip:


What a cool idea!! Very nice twist on a football pool, with no actual "betting" on the game, since the proceeds benefit Portlight's relief efforts in Haiti. Tdude, if you have the time, please contact individual blog owners and post this around with their permission. The first one that comes to mind is Pat's...we all know who he's picking!! :)

Geoff - I'm hoping ShelterBox can help now with Portlight's immediate need for tents in Haiti, but I'll make sure they're aware of our ongoing need in future relief efforts. I think they'd be a great long-term partner for us!



That's Great! After a crappy day at work...I feel a lot better :)
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am I gonna get flagged for spamming since I posted it twice ;)
Member Since: June 28, 2006 Posts: 25 Comments: 8357
Renewable energy is helping China complete its economic transformation and achieve "energy security". China rapidly has moved along the path of renewable energy development.[1] About 16 percent of China's electricity came from renewable sources in 2006, led by the world's largest number of hydroelectric generators.[2] Total installations of hydropower reached 145,000 MW in 2007. China has set a target of 190,000 MW for 2010.[3] Technology development and increased amounts of investment in renewable energy technologies and installations has increased markedly throughout the 2000s in China, and investment in renewables is now part of China's economic stimulus strategy.[4] Researchers from Harvard University and Tsinghua University have found that China could meet all of their electricity demands from wind power through 2030
http://en.wikipedia.org/wiki/Renewable_energy_in_China
Member Since: September 22, 2005 Posts: 11 Comments: 2032
so here is a repost:

So, GeoffreyWPB came up with a spectacular idea!

Go to my blog, pick the team you think will win the Super Bowl. If your team does not win, then you will donate $10 to Portlight! Great way to raise money for Portlight, have fun, and root on your favorite team!

so get to work! My blog
Member Since: June 28, 2006 Posts: 25 Comments: 8357
Quoting presslord:
OK...I'm in...


gotcha!

Quoting LongStrangeTrip:


What a cool idea!! Very nice twist on a football pool, with no actual "betting" on the game, since the proceeds benefit Portlight's relief efforts in Haiti. Tdude, if you have the time, please contact individual blog owners and post this around with their permission. The first one that comes to mind is Pat's...we all know who he's picking!! :)

Geoff - I'm hoping ShelterBox can help now with Portlight's immediate need for tents in Haiti, but I'll make sure they're aware of our ongoing need in future relief efforts. I think they'd be a great long-term partner for us!



will do! this should be exciting (:
Member Since: June 28, 2006 Posts: 25 Comments: 8357
I am in!
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706. xcool
hey matt
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OK...I'm in...
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Quoting tornadodude:


great, I'm gonna update my blog with the names and who they bet for each time someone decides who they are going for


What a cool idea!! Very nice twist on a football pool, with no actual "betting" on the game, since the proceeds benefit Portlight's relief efforts in Haiti. Tdude, if you have the time, please contact individual blog owners and post this around with their permission. The first one that comes to mind is Pat's...we all know who he's picking!! :)

Geoff - I'm hoping ShelterBox can help now with Portlight's immediate need for tents in Haiti, but I'll make sure they're aware of our ongoing need in future relief efforts. I think they'd be a great long-term partner for us!

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Quoting xcool:
hi


hey man
Member Since: June 28, 2006 Posts: 25 Comments: 8357

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

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