Why hasn't the stratosphere cooled for 15 years?

Question

http://www.ssmi.com/msu/msu_data_description.html#msu_amsu_time_series

As you can see from the TLS (bottom graph) on figure 7, the stratosphere has not cooled for roughly 15 year. Isn't it part of AGW theory that the stratosphere should cool? Why isn't it?

Answer 1

Good article on upper atmosphere cooling:

http://www.sciencemag.org/cgi/content/fu...

Discussion of overall cooling, showing the lower stratosphere data is not the best metric to show overall cooling of the upper atmosphere (since the data is contaminated from warming troposphere and ozone loss):

http://www.atmosphere.mpg.de/enid/20c.ht...

(See figure 3 for full explanation of why lower troposphere is not the best metric.)

(Tip of the hat to the folks at realclimate.org for the links!)

Edit:  Anyone interested in this topic would be advised to spend the half hour and listen to this:

http://ams.confex.com/ams/15isa14m/techp...

Answer 2

The correct answer is no-one really knows.  If you start off with the hypothesis that man is everything, then man must have caused everything and it must be carbon emissions.  If you start off believing in a creator, it is probable the creator.

Answer 3

Your own link provides this data:

Channel TLS  

Start Time: 1979

Stop Time: 2008-03

Number of Years: 29

Global Trend: -0.314 K/decade

Now I'm not sure what kind of "math" you studied in school, but in all my numerical analysis and statistics courses a trend of -0.314 K/decade would definitely be considered cooling.

You must be confusing weather with climate. Climate is defined as the average of weather over a long period of time (typically around 30 years).  Global warming is all about climate change, not weather.

Answer 4

One of the reasons suggested for stratospheric cooling is that more infrared (re-)radiation from the Earth is being trapped by increasing atmospheric carbon dioxide and is thus unavailable to warm the stratosphere (you are required to ignore any thought of saturation to believe this). Another, more plausible explanation would be reduced stratospheric ozone (ozone is a greenhouse gas) from whatever cause and the stratosphere is thus capturing less energy and cooling.

Or maybe humans are so Hot-headed that our chrome domes are preventing anything COOL from ever happening again.

Answer 5

The computer models have never been able to predict accurate outcomes.

AGW theory is based largely on computer models, need I say more.

Answer 6

Unfortunately you're wrong:

STRATOSPHERE TEMPERATURE DATA SUPPORT SCIENTISTS’ PROOF FOR GLOBAL WARMING

http://earthobservatory.nasa.gov/Newsroo...

“These results are consistent with the results that the Nature paper gets,” Fu said. “It is an independent check of the problem because we used completely independent data sets. The independent observations agree with our conclusions, and that’s quite powerful evidence.”

The Fu team’s work indicates the troposphere has been warming at about two-tenths of a degree Celsius, or nearly one-third of a degree Fahrenheit, per decade. That closely resembles measurements of warming at the surface, something climate models have suggested would result if the warmer surface temperatures are the result of greenhouse gases.

The findings are important because, for years, satellite data inconsistent with warming at the surface have fueled the debate about whether climate change is actually occurring.

So much for "anyone can see" reasoning.  If your premise were true, you could easily point to a peer-reviewed scientific paper confirming it.  Go ahead, provide the link, we'd love to see it...

Answer 7

Didn't warm either

Answer 8

The scientists who wrote the article disagree with you about what Channel TLS is saying.  Both in the line they draw through the data and:

"Channel TLS (Lower Stratosphere) is dominated by stratospheric cooling, punctuated by dramatic warming events caused by the eruptions of El Chichon (1982) and Mt Pinatubo (1991)."

No offense, but I'm going with them.

Answer 9

Pretty simple - even ignoring the long-term trend and focusing on the short-term (which is almost never a good idea), the tricky thing about the stratospheric temperature is that it also depends on ozone levels.  More ozone causes the stratosphere to warm, and the ozone layer has been recovering over the past decade or two.

"Ozone's impact on climate consists primarily of changes in temperature. The more ozone in a given parcel of air, the more heat it retains. Ozone generates heat in the stratosphere, both by absorbing the sun's ultraviolet radiation and by absorbing upwelling infrared radiation from the lower atmosphere (troposphere). Consequently, decreased ozone in the stratosphere results in lower temperatures."

http://www.giss.nasa.gov/research/featur...

Stratospheric temp vs. ozone graph illustrates the point perfectly:

http://www.giss.nasa.gov/research/featur...

That's why it's important to look at all layers of the upper atmosphere (which are cooling as AGW predicts) and not just the stratosphere.

http://answers.yahoo.com/question/index;...

http://www.realclimate.org/index.php/arc...

Answer 10

I can't find the data files in the link you give, so my analysis here is just based upon eyeballing the graph (i.e. exactly what you've done ; ) ).

What strikes me is that, while the trend for the past 15 years looks null or positive, the trend for the past 8 years appears to be negative. As a general rule, when your trend depends that much on what your starting year is (1993 as opposed to 2000), you're not looking at enough data.

So for now I'm writing this trend off as noise over a longer term trend (just like the period from 1984 to 1991). You just don't have enough data to obtain any meaningful result.

Edit:

Ah, wonderful. I don't know why I didn't spot that file before. Now we can get down to business.

"This is an odd thing to say anyway. Not only is the trend the same at both 93 and 2000, but by your logic, because the trend is different in 79 than in 93, your not looking at enough data."

You misunderstand. What I'm saying is that your trend depends entirely on the year you've chosen to start on. Check it out. The trend for the period from 1993-2007 (14 years) is approximately .00857 ºC/dec, while the trend for the period 1992-2007 is *negative* 0.0496 ºC/dec. What we have here is a classic example of cherry picking.

The reason your example is different is because we have enough data for the period 1979-1993 that if we were to start our trend in, say 1980, the resulting trend would be almost identical to the trend from 1979. (Try it and see.)

Here's an excellent article from RealClimate explaining this issue better than I can:

http://www.realclimate.org/index.php/arc...