2010-09-04 18:19:44Basic Rebuttal 39 "Satellites show no warming in the troposphere"
dansat
dannysatterfield@mac.com
15
24.214.40.2

Satellites can be used to measure the temperature of the troposphere but it's not that straight forward. Sensors called microwave sounding units have flown in space on a variety of different satellites since 1978. There is enough overlap of the data for a record of temperatures from 1978 to the present.

Each sensor is slightly different and more recent satellites have used improved designs with greater resolution. These sensors have to be calibrated to match and errors removed.

Another problem develops when measuring the upper troposphere. The sensors do not just see the middle troposphere but also are influenced by the lower stratosphere. Adjustments must be made to "ignore" the stratosphere and derive a temperature trend in just the troposphere. This is further complicated even because the stratosphere should be (and is) cooling due to climate change.

John Christy and Roy Spencer of the University of Alabama published a series of papers starting about 1990 that indicated the troposphere was warming at a much slower rate than the surface temperature record and climate models indicated. One early version of their data even showed a cooling trend.

Temperature trends of the troposphere now match well with the surface based trend.

Several groups of scientists began looking closely at this discrepancy. With so many other pieces of evidence indicating warming, it seemed unlikely that the troposphere would not be warming. Errors were soon found in the UAH data.

The satellites must pass over the same spot on Earth at the same time each day to get a temperature average. In reality the time the satellite passes drifts slightly as the orbit slowly decays. To compensate for this and other orbital changes a series of adjustments must be applied to the data.

The adjustments that Christy and Spencer originally applied were found to be incorrect. When the correct adjustments to the data were applied the data matched much more closely the trends expected by climate models. It was also more consistent with the historical record of troposphere temperatures obtained from weather balloons. 

At least two other groups keep track of the tropospheric temperature using satellites and they all now show warming in the troposphere that is consistent with the surface temperature record. Furthermore data also shows now that the stratosphere is cooling as predicted by the physics.

All three groups measuring temperatures of the troposphere show a warming trend.  The U.S. Climate Change Science Program produced a study in April 2006 on this topic. Lead authors included John Christy of UAH and Ben Santer of Lawrence Livermore National Labs. The first page has this quote "Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the reliability of climate models and the reality of human-induced global warming...This significant discrepancy no longer exists because errors in the satellite and radiosonde data have been identified and corrected. New data sets have also been developed that do not show such discrepancies."

2010-09-04 19:06:38Sin of omission
gpwayne
Graham Wayne
graham@gpwayne...
81.152.234.172

Hi Dan. Do you think there might be too much technical detail here, which could just be boiled down to a brief overview of the difficulties, adjustments etc. In some ways, you've put in more detail here than there is in the intermediate version.

But the main thing is you have not mentioned the uncertainties about the tropics. I believe we must be very candid, for if it can be made to look as if we are concealing uncertainty, it can be used against us, and this site.

And could you include the figure caption in text underneath (rather than just in a pop-up), plus an attribution of copyright and a link to the source?

2010-09-04 19:17:44Another point
nealjking

nealjking@gmail...
84.151.49.66

As I recall, the Spencer/Christy discrepancy was a problem for about a decade. During that time, it was a source of cheer to deniers, whilst the scientists kept saying that there must be a problem somewhere, because of the record on the ground.

The fact that it took so long to finally pin down the problem shows two valuable things:

- Experimental science is not easy: Sometimes it takes a very long time to pin down a problem; and

- Sometimes it makes sense to believe that the data are wrong, if there is otherwise too much disruption to well-established science. 

Of course, this can only be justified finally by ultimately finding the resolution; otherwise, it becomes time for a "Kuhn-ian revolution'. But nobody is suggesting this now, because there is no alternative coherent theory for what is going on with the climate. 

 

2010-09-05 00:31:59
doug_bostrom

dbostrom@clearwire...
184.77.83.151

I w/Graham here Dan. I think you could remove the first three paragraphs and get straight to the argument, then simply change "Errors were soon found in the UAH data." --> "Errors were soon found in Christy and Spencer's analysis due to problems with how they were deriving temperatures from the raw satellite data."

The rest of the writeup is good!

2010-09-05 07:11:45I don't think it's quite fair
nealjking

nealjking@gmail...
84.151.49.66

to say that "Errors were soon found in the UAH data." I haven't been able to pin it down and I'm not familiar with the original literature, but a Wiki article (http://en.wikipedia.org/wiki/File:Satellite_Temperatures.png) indicates that the UAH problem was noticed at least as early as 2003 and was not fixed until 2006. 3 years is not "soon"; and from what I remember reading before, it was really more like 10 years.

I think this is an important point, because it shows that when it's a choice between your entire intellectual framework and some data, that sometimes you're better off going with your intellectual framework, and assuming that the data will eventually be straightened out. There are still discrepancies in the data (tropospheric hotspot, for example); I sent a note to Gavin Schneider about one of them, and he said that it could very likely be a bad-data issue.

 I think it's a win for science when you take a guess on the most likely result, and are eventually vindicated.

 

Neal

 

 

2010-09-06 05:54:16Thanks!
dansat
dannysatterfield@mac.com
15
24.214.40.2

Good ideas all.

I considered the tropical uncertainty question. It seemed to be getting long, so I left it out and I think the quote at the end may not be needed.

Doug, You make a good point will adjust and try to get more quickly into the gist of it.

Neal and GP, Points taken and I like the idea of using the original data to point out how science works. I had that in mind as I wrote it but you are right, it should be directly stated. I've often used this issue to make just such a point. 

Dan 

2010-09-06 14:36:00Revised #39 Satellites show no warming
dansat
dannysatterfield@mac.com
15
24.214.40.2

Here is a revised draft. I added in the uncertainty in the tropics and deleted the first two paragraphs to tighten it up. I also added a bit about how this episode is a good example of how science works.

*** 

John Christy and Roy Spencer of the University of Alabama published a series of papers starting about 1990 that indicated the troposphere was warming at a much slower rate than the surface temperature record and climate models indicated. One early version of their data even showed a cooling trend.

Several groups of scientists began looking closely at this discrepancy. With so many other pieces of evidence indicating warming, it seemed unlikely that the troposphere would not be warming. Errors were soon found in the UAH data.

The satellites must pass over the same spot on Earth at the same time each day to get a temperature average. In reality the time the satellite passes drifts slightly as the orbit slowly decays. To compensate for this and other orbital changes a series of adjustments must be applied to the data. 

Temperature trends of the troposphere now match well with the surface based trend.

The adjustments that Christy and Spencer originally applied were found to be incorrect. When the correct adjustments to the data were applied the data matched much more closely the trends expected by climate models. It was also more consistent with the historical record of troposphere temperatures obtained from weather balloons. 

At least two other groups keep track of the tropospheric temperature using satellites and they all now show warming in the troposphere that is consistent with the surface temperature record. Furthermore data also shows now that the stratosphere is cooling as predicted by the physics.

All three groups measuring temperatures of the troposphere show a warming trend.  The U.S. Climate Change Science Program produced a study in April 2006 on this topic. Lead authors included John Christy of UAH and Ben Santer of Lawrence Livermore National Labs.

The first page has this quote "Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the reliability of climate models and the reality of human-induced global warming...This significant discrepancy no longer exists because errors in the satellite and radiosonde data have been identified and corrected. New data sets have also been developed that do not show such discrepancies."

There are still some discrepancies between satellite measured temperatures in the tropics and those measured by radiosondes. Most researchers believe this difference is likely due to instrument errors. 

The original discrepancy is an excellent example of how science works and of critical thinking. With many different indicators showing warming it did not make sense that the troposphere would be cooling. Instead of asuming that all the other lines of evidence were wrong, the new evdence was first examined closely.

Science advances by trial and error. This error has taught researchers a lot about measuring the temperature of our planet from space.  

2010-09-06 15:59:16Still missing discussion on wisdom of holding out
nealjking

nealjking@gmail...
91.33.100.6

dansat,

 As we discussed above, it would be useful to capitalize on the way that science self-corrects. Indeed, your final paragraphs state:

"The original discrepancy is an excellent example of how science works and of critical thinking. With many different indicators showing warming it did not make sense that the troposphere would be cooling. Instead of asuming that all the other lines of evidence were wrong, the new evdence was first examined closely." (btw, spelling errors)

 However, an earlier paragraph still says:

"Several groups of scientists began looking closely at this discrepancy. With so many other pieces of evidence indicating warming, it seemed unlikely that the troposphere would not be warming. Errors were soon found in the UAH data."

However, your write-up indicates that the original report from UAH was in 1990, and the errors were not identified until 2006. 16 years is not "soon".

I think you should say something like:

"Several groups of scientists began looking closely at this discrepancy. With so many other pieces of evidence indicating warming, it seemed unlikely that the troposphere would not be warming. However, this discrepancy remained an outstanding problem for many years."

LIKEWISE:

"The satellites must pass over the same spot on Earth" SHOULD BE CHANGED TO:

"To understand what was wrong: The satellites must pass over the same spot on Earth"

 

"The adjustments that Christy and Spencer originally applied were found to be incorrect." SHOULD BE CHANGED TO:

"After many years, it was found that the adjustments that Christy and Spencer had originally applied were incorrect."

 

 "Instead of asuming that all the other lines of evidence were wrong, the new evdence was first examined closely." SHOULD BE CHANGED TO:

 "This discrepancy was taken very seriously by the scientific community, and the consistency and accuracy of all relevant data were examined intensely."

2010-09-06 16:36:42
doug_bostrom

dbostrom@clearwire...
184.77.83.151

Awful ninky point: two occurrences of "indicated" in first sentence. Maybe:

"John Christy and Roy Spencer of the University of Alabama published a series of papers starting about 1990 indicating the troposphere was warming at a much slower rate than the surface temperature record and climate models predicted." 

 

 

  

2010-09-06 16:51:22Good to go in my view
gpwayne
Graham Wayne
graham@gpwayne...
81.152.234.172
Hi Dan - like this a lot now and think it's ready to go, hence the thumb...
2010-09-06 16:52:49...brainless...
gpwayne
Graham Wayne
graham@gpwayne...
81.152.234.172
...or it would be 'hence the thumb' if I remembered to click on the damn thing. Why JC doesn't program some telepathy into this site is beyond me :)
2010-09-06 17:13:54We're all friends...
gpwayne
Graham Wayne
graham@gpwayne...
81.152.234.172
Hey Neal - I'm sure we all appreciate your contributions, but could I just suggest that when you say things like "SHOULD BE CHANGED TO" (in caps, no less) it appears rather more like an instruction than a suggestion. We all have our opinions, but we are also obliged to respect each other's point of view and be constructive when we agree to differ.
2010-09-06 18:36:37THE CAPS
nealjking

nealjking@gmail...
91.33.100.6

were just a device to clearly separate the texts.

Not intended as admonishment.

2010-09-07 00:16:49Take account of Neil's suggestions and run.
jimalakirti

jimalakirti@gmail...
70.58.169.156

I think the article is good to go, and would be even better of some of Neil's suggestions were incorporated (particularly the matter of "time").

 I took the CAPS to mean "THIS IS MY SUGGESTION AND NOT PART 0F THE QUOTED TEXT!".

 

Pardon me. I appear to be shouting.  

2010-09-09 01:38:11
doug_bostrom

dbostrom@clearwire...
184.77.83.151
Oops, I intended to vote when I lodged my earlier remark about "indicated." 
2010-09-09 03:59:32links
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.249
I'd suggest adding some references.  For example, Spencer and Christy (1992) can be the reference for the first part of the article.  For the corrections to their analysis, you could reference Mears et al. (2003) and Mears et al. (2005).  I'd also include a link to the U.S. Climate Change Science Program study.
2010-09-09 20:28:21
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.155.213
A layman's perspective here, but maybe the basic version should include a paragraph or two briefly summing up what the MSU instruments on the satellites actually are and how the satellite data set is created?. I suspect a lot of non-experts think they are sky based thermometers & the less educated skeptics will be disappointed that it involves modelling. 
2010-09-10 13:08:06Good suggestions
dansat
dannysatterfield@mac.com
15
76.164.173.162

All your comments are helpful. Will do a third revision. I did plan on adding is references as well. I need to a little research on the time table between Christy's early 90's paper and the corrections. I bases a lot of it on the U.S.Climate Change program study. Ben Santer was one of the authors and told me some of the details of how difficult that was to get settled... ;)

 Dan

2010-09-10 17:57:52Satellites and warming - 3rd Revision
dansat
dannysatterfield@mac.com
15
24.214.40.2

Here is the 3rd revision and you will notice I have taken the suggestions to heart. I have also rearranged the end slightly. References added and spelling checked. Also changed the first indicated to implied.

**** 

John Christy and Roy Spencer of the University of Alabama published a series of papers starting about 1990 that implied the troposphere was warming at a much slower rate than the surface temperature record and climate models indicated Spencer and Christy (1992). One early version of their data even showed a cooling trend (Christy et al. 1995).

Several groups of scientists began looking closely at this discrepancy. With so many other pieces of evidence indicating warming, it seemed unlikely that the troposphere would not be warming. Errors were discovered in the methods the UAH group used to adjust the data.

To understand what was wrong: The satellites must pass over the same spot on Earth at the same time each day to get a temperature average. In reality the time the satellite passes drifts slightly as the orbit slowly decays. To compensate for this and other orbital changes a series of adjustments must be applied to the data. 

Temperature trends of the troposphere now match well with the surface based trend.

There are also differences between the sensors that were onboard each satellite and merging this data to one continuous record is not easily done. It was nearly 13 years after the orginal papers that the adjustments that Christy and Spencer originally applied were found to be incorrect. Mears et al. (2003) and Mears et al. (2005)

When the correct adjustments to the data were applied the data matched much more closely the trends expected by climate models. It was also more consistent with the historical record of troposphere temperatures obtained from weather balloons. As better methods to adjust for biases in instruments and orbital changes have been developed, the differences between the surface temperature record and the troposphere have steadily decreased.

At least two other groups keep track of the tropospheric temperature using satellites and they all now show warming in the troposphere that is consistent with the surface temperature record. Furthermore data also shows now that the stratosphere is cooling as predicted by the physics.

All three groups measuring temperatures of the troposphere show a warming trend.  The U.S. Climate Change Science Program produced a study in April 2006 on this topic. Lead authors included John Christy of UAH and Ben Santer of Lawrence Livermore National Labs.

The first page has this quote "Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the reliability of climate models and the reality of human-induced global warming...This significant discrepancy no longer exists because errors in the satellite and radiosonde data have been identified and corrected. New data sets have also been developed that do not show such discrepancies."

There are still some discrepancies between satellite measured temperatures in the tropics and those measured by radiosondes. Most researchers believe this difference is likely due to instrument errors. 

The original discrepancy is an excellent example of how science works and of critical thinking. With many different indicators showing warming, it did not make sense that the troposphere would be cooling. This discrepancy was taken very seriously by the scientific community, and the consistency and accuracy of all relevant data were examined intensely. 

Science advances by trial and error. The result is an increased knowledge of how to measure the temperature of the troposphere from space.

 

2010-09-10 18:52:22I think this is much improved
nealjking

nealjking@gmail...
91.33.124.196

The discrepancy issue is woven into the narrative, and it makes the case that confidence in the science is ultimately boosted by surviving this challenge: "What does not kill me makes me stronger."

However, at the very beginning, you still have:

"Several groups of scientists began looking closely at this discrepancy. With so many other pieces of evidence indicating warming, it seemed unlikely that the troposphere would not be warming. Errors were soon found in the UAH data."

It is not clear which errors were found "soon": the rest of the narrative states explicitly that the calculated corrections were only realized to be wrong 13 years later. I think the only thing that was noticed soon was the discrepancy between the data trends.

Maybe something like, "The UAH data became a focus of concern for the climatological community." 

2010-09-11 02:36:12formatting
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.249

A formatting correction - the references should be within the sentences citing them.  Like so:

a much slower rate than the surface temperature record and climate models indicated (Spencer and Christy 1992). One early version of their data even showed a cooling trend (Christy et al. 1995).

It was nearly 13 years after the orginal papers that the adjustments that Christy and Spencer originally applied were found to be incorrect (Mears et al. 2003 and 2005). 

In addition to neal's comment above, I'd also change the sentence to state that errors were found in the data analysis, not the data itself.

2010-09-11 06:13:22Comment
Robert Way

robert_way19@hotmail...
142.162.205.242
I think it is good to go. I might suggest that plotting the actual data might make the graphs a bit less choppy but either way good work.
2010-09-11 06:56:42
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.253.185

Dansat, ditto on changing "Errors were soon found in the UAH data" to "errors were found in the UAH analysis"

"The MSU satellite data is collected from a number of satellites orbiting & providing daily coverage of some 80% of the Earth's surface, each day the orbits shift and 100% coverage is achieved every 3-4 days.  The microwave sensors on the satellites do not directly measure temperature, but rather radiation given off by oxygen in the Earth's atmosphere. (trying to reduce technical jargon here - radiative brightness, upwelling etc). The intensity of this radiation is directly proportional to the temperature of the air and is therefore used to estimate global surface temperatures.

"To understand what was wrong...............the orbit slowly decays, changing the angle at which measurements are taken and east/west drift of the satellites alters the time of the day when readings are taken."

 

2010-09-11 08:54:32Satellites and warming 4th rev.
dansat
dannysatterfield@mac.com
15
76.164.173.162

Here is the 4th rev. 

 Formatting corrected and I changes the second paragraph to fix the data implications. Thanks for catching that! I also added in Dappledwater's suggested paragraph but dropped surface from temps. I was still wanting to put a more basic explanantion of the process and that was short and sweet. Again thanks.


Also I dropped soon and just said errors were discovered in the methods without stating when since the comments began almost immediately after the first papers were published with the major errors found in the early 2000's.

Take a look and see what you all think.

Dan

***********************************

 

John Christy and Roy Spencer of the University of Alabama published a series of papers starting about 1990 that implied the troposphere was warming at a much slower rate than the surface temperature record and climate models indicated Spencer and Christy (1992). One early version of their data even showed a cooling trend (Christy et al. 1995).

Several groups of scientists began looking closely at this discrepancy. With so many other pieces of evidence indicating warming, it seemed unlikely that the troposphere would not be warming. Errors were discovered in the methods the UAH group used to adjust the data.

To understand what was wrong: The satellites must pass over the same spot on Earth at the same time each day to get a temperature average. In reality the time the satellite passes drifts slightly as the orbit slowly decays. To compensate for this and other orbital changes a series of adjustments must be applied to the data. 

Temperature trends of the troposphere now match well with the surface based trend.

The MSU satellite data is collected from a number of satellites orbiting & providing daily coverage of some 80% of the Earth's surface. Each day the orbits shift and 100% coverage is achieved every 3-4 days.  The microwave sensors on the satellites do not directly measure temperature, but rather radiation given off by oxygen in the Earth's atmosphere.  The intensity of this radiation is directly proportional to the temperature of the air and is therefore used to estimate global temperatures. 

There are also differences between the sensors that were onboard each satellite and merging this data to one continuous record is not easily done. It was nearly 13 years after the orginal papers that the adjustments that Christy and Spencer originally applied were found to be incorrect. Mears et al. (2003) and Mears et al. (2005)

When the correct adjustments to the data were applied the data matched much more closely the trends expected by climate models. It was also more consistent with the historical record of troposphere temperatures obtained from weather balloons. As better methods to adjust for biases in instruments and orbital changes have been developed, the differences between the surface temperature record and the troposphere have steadily decreased.

At least two other groups keep track of the tropospheric temperature using satellites and they all now show warming in the troposphere that is consistent with the surface temperature record. Furthermore data also shows now that the stratosphere is cooling as predicted by the physics.

All three groups measuring temperatures of the troposphere show a warming trend.  The U.S. Climate Change Science Program produced a study in April 2006 on this topic. Lead authors included John Christy of UAH and Ben Santer of Lawrence Livermore National Labs.

The first page has this quote "Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the reliability of climate models and the reality of human-induced global warming...This significant discrepancy no longer exists because errors in the satellite and radiosonde data have been identified and corrected. New data sets have also been developed that do not show such discrepancies."

There are still some discrepancies between satellite measured temperatures in the tropics and those measured by radiosondes. Most researchers believe this difference is likely due to instrument errors. 

The original discrepancy is an excellent example of how science works and of critical thinking. With many different indicators showing warming, it did not make sense that the troposphere would be cooling. This discrepancy was taken very seriously by the scientific community, and the consistency and accuracy of all relevant data were examined intensely. 

Science advances by trial and error. The result is an increased knowledge of how to measure the temperature of the troposphere from space.

2010-09-11 10:18:51Looking good
nealjking

nealjking@gmail...
91.33.124.196
Go
2010-09-11 10:47:38
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.150.110
Dansat, yeah noticed the "surface temp" after I'd clicked "submit", whoops. Sorry to be so picky, but I think the order of paragraphs 3 & 4 should be reversed, otherwise good to go I reckon. 
2010-09-11 13:09:44formatting again
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.137.148.215

The formatting's still not quite right - see my last post again, the parentheses should be around the authors' names as well as the year if at the end of a sentence.  You got it right with the Christy 1995 reference.

 If you're citing them like "According to Spencer and Christy (2003)....", then the parentheses just go around the year.  But when it's like "Later studies discovered their error (Mears et al. 2005)", then the parentheses go around the whole thing.

Also make sure you don't have a period before the citation.

Other than that it's good to go.

2010-09-12 20:10:18Published
John Cook

john@skepticalscience...
121.222.93.62

Great post, Dan, many thanks! One minor tweak, turned the USCCSP quote into a blockquote - I like the visual structure you get when you indent quotes, it visually breaks up the text, makes for more readability (can you spot I'm a typographical nerd by day?)

2010-09-14 19:21:27for dansat
nealjking

nealjking@gmail...
91.33.111.29

There was a suggestion regarding the Intermediate version of this topic in the Intermediate Rebuttal listing. Maybe you would be in the best position to consider that point?