By Steve Goddard and Anthony Watts
Some of the excellent readers of the last piece we posted on WUWT gave me an idea, which we are following up on here. The exercise here is to compare GISS and satellite data (UAH and RSS) since the start of 2003, and then propose one possible source of divergence between the GISS and satellite data. The reason that the start of 2003 was chosen, is because satellite data shows a rapid decline in temperatures starting then, and GISS data does not. The only exception to the downward trend was an El Nino at the start of 2007, which caused a short but steep spike. Remembering back a couple of years, Dr. Hansen had in fact suggested that El Nino might turn into a “Super El Nino” which would cause 2007 to be the “hottest year ever.”
The last six years (2003-2008) show a steep temperature drop in the satellite record, which is not present in the GISS data. Prior to 2003, the three trends were all close enough to be considered reasonably consistent, but over the last six years is when a large divergence has become very apparent both visually and mathematically.
Since the beginning of 2003, RSS has been dropping at 3.60C/century, UAH has been dropping at 2.84C/century, and GISS has been dropping at 0.96C/century. All calculations are done in a Google Spreadsheet here:
The divergence between GISS and RSS is shown below. Since the start of 2003, GISS has been diverging from RSS at 2.64C/century, and GISS has been diverging from UAH at 1.87C/century. RSS has been diverging from UAH at minus 0.76C/century, indicating that RSS temperatures have been falling a little faster than UAH over the last six years, as can also be seen in the graph above.
Below is a 250km map of GISS trends from 2003-2008. One thing which stands out is that GISS has large areas with sparse or no coverage. Notably in Africa, Antarctica, Greenland, Canada, Brazil, and a few other places.
Click for larger image
Many of the GISS holes seem to be in blue regions on the map. Here is a post and video of the GHCN station loss over the past several years globally, created by WUWT contributor John Goetz:
Here are two images showing the difference between GISS global coverage in 1978 and 2008:
Click for a larger image
Click for a larger image
There is a tremendous amount of station dropout in 30 years. Dropout is worst in the high northern latitudes, most all of Canada, and about half of Africa. Of particular note is the red band at the southernmost latitude, which “seems” to indicate a continuous coverage there. Of course we know that is not true, given the paucity of stations in the Antarctic interior. Read more here.
By contrast, while it doesn’t hit both poles (neither does GISS) UAH has much broader global coverage as seen below. Could this be part of the explanation for the divergence between GISS and satellite data? What do the readers think?
![[Image]](https://i0.wp.com/discover.itsc.uah.edu/amsutemps/browse/AMSU_A_15.latest.a_04.png?resize=520%2C278&quality=75)
Click for larger image
![[Image]](https://i0.wp.com/discover.itsc.uah.edu/amsutemps/browse/AMSU_A_15.latest.d_04.png?quality=75)
Click for larger image
How different would the GISS graph appear, if it showed a -3.6C/century cooling trend over the last six years? For reference, the steep GISS warming trend from 1980 to 2002 was about 0.4 degrees.
Speaking of divergence, there is this from the NYT: http://www.nytimes.com/2009/01/22/science/earth/22climate.html?_r=1&hp
Meanwhile the ice ignores the debate: http://www.arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.south.jpg
Anthony, Just for the record, found on Gore Lied a.o in response to this posting :
Pigs are flying! An email below from Henry Geraedts [arbutuspoint@gmail.com]
I am drawing your attention to a significant change in GISS GHG temperature trend projections published by Jim Hansen’s team last week, and which appears to have gone largely unnoticed other than by Lucia Liljegren on her site “The Blackboard” [ http://www.rankexploits.com].
At the very end of the GISS update, under para #4 in the next to last paragraph, Hansen & Co state that: “From climate models and empirical analyses this GHG forcing translates into a mean warming rate of 0.15C per decade”. Given that Jim Hansen is one of the leading and vocal proponents of the AGW/ACC hypothesis, that the GISS temperature data series has yet again come close scrutiny recently [Lubos Motl, et. al] and that GISS temperature data is increasingly at odds with satellite data [ref: today’s posting on that subject at http://www.wattsupwiththat.com ] this revision is singularly noteworthy: the revised GISS GHG driven temperature trend is a whopping 25% lower than the IPCC’s [95% certain] “gold standard” of 0.20C per decade.
Absent a GISS press release advising all of us of this change [which clearly would have been expecting too much], I thought you and your readers would find this of interest.
Folks,
I’m incredibly impressed by this site and the thoughtful discussion. It’s very enlightening and, I think, very valuable to those of us who have been “smelling a rat” in the pablum from the media.
Thank each and every one of you, including the civil skeptics of the skeptics. The interplay is very instructive and helpful.
Mark
Definitely weakening: http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.1.22.2009.gif
Ron de Haan:
From Lucia’s site: click
It seems that the IPCC’s AR-4 has been falsified.
Andrew,
What happened to my comment on temperature retrievals from radiances that did
not agree with your messsage from Dr. Christy? Is this thread a result of that comment?
Clearly if the surface station data is being used in the retrievals as I Indicated, then a loss
of surface data would cause a divergence between the satellite retrievals and surface temperatures. You need to give credit where it is due and not a vague statement
as at the beginning of this thread.
Jerry
Uh, was that previous comment meant for Anthony?
Anthony,
What happened to my comment on temperature retrievals from radiances that did
not agree with your messsage from Dr. Christy? Is this thread a result of that comment?
Clearly if the surface station data is being used in the retrievals as I Indicated, then a loss
of surface data would cause a divergence between the satellite retrievals and surface temperatures. You need to give credit where it is due and not a vague statement
as at the beginning of this thread.
And what happened to the thread that contained the message from Dr. Christy
where he so adamantly insisted that there was no use of surface data in the temperature retrieval?
Jerry
REPLY: I don’t know what happened to your comment. I have no idea what it was and do not recall it. It has been months since this thread was active, and I have over 67,000 comments on this blog. If it contained something that put it in the spam filter or violated policy it probably was deleted. It is also possible your comment is on another thread. – Anthony Watts
Anthony,
Where is Dr. Christy’s response to your inquiry about the independence of satellite data
and surface temperature data. That seems to also have disappeared ( do a search on Christy). That message is why I wrote the my comment s and it seems a bit strange that both have disappeared?
Jerry
Anthony,
Please indicate a search key word that will bring up the response of Dr. Christy
to your inquiry about satellite temperature retrievals being independent of surfact temperature data. Thank you.
Jerry
Anthony,
According to the date at the beginning of this thread, it was started on January 18, 2009.
That is roughly when I sent in my comment in response to Dr. Christy’s message.
Once we find Dr. Christy’s message this should all be resolved.
Jerry
Gerry
1. I still have no idea what you are talking about
2. Search on “John Christy” in the search box upper right for any comments or threads
3. Nothing has been deleted, especially any comment by John Christy.
Are you certain it was this blog where you think you saw this? Because absolutely nothing you are saying rings any bells.
I think you may be talking about this comment at Climate Audit
http://www.climateaudit.org/?p=4687#comment-316393
-Anthony
Anthony,
I am positive it was this site. I have never had any problem on CA as all comments are time stamped and Steve keeps records of all threads.
Did you write a message to John Christy asking him about the dependence of satellite temperature retrieval being independent of surface temperature data (with words to the effect that you would go directly to the source to check if that was the case)?
Jerry
REPLY: If you’ll pay attention to the header for each comment, you’ll notice that all comments are time stamped here as well and that they remain here also. I wrote no such message to Dr. Christy in this thread. – Anthony
Anthony,
That is not the comment on CA. You only need to state whether or not you wrote a message to John Christy asking about satellite temperature retrievals.
Yes or no.
Jerry
REPLY: In this thread, most definitely no. But if you can speak to the context of the discussion perhaps I can figure out what thread you are talking about. The problem is you keep using the phrase “satellite temperature retrievals” and that does not ring a bell nor any search results. Given that you couldn’t even get my name right, (I’m not Andrew) perhaps you are mistaken about the terminology or phrase.
Like I said, you can search the entire blog on John Christy in the upper right. No posts from him have been deleted that I am aware of. It is not my responsibility to find things for you, but you are most welcome to search. – Anthony Watts
Gerry/Jerry
Well I though about a bit, this might be it, on UAH MSU technology, way back in August of 08 where I asked Christy about the technology.
http://wattsupwiththat.com/2008/03/08/putting-a-myth-about-uah-and-rss-satellite-data-to-rest/
There are two comments from you there, one of which where you can’t even spell your own name right. “Gerlad”.
You might want to work on that before you accuse me of deleting things or losing things. I don’t answer things not addressed to me. You addressed them both to “Andrew” who was also in the thread as another commenter.
Dr. Christy states in that thread that no surface data is used in the UAH MSU data process. If you have something that says otherwise, I welcome you to share it. – Anthony
Anthony,
> Well I though about a bit, this might be it, on UAH MSU technology, way back in August > of 08 where I asked Christy about the technology.
>http://wattsupwiththat.com/2008/03/08/putting-a-myth-about-uah-and-rss-satellite-data-to-rest/
Well so I see you finally found John Christy’s response to your inquiry about satellite
retrievals of temperature. I wrote John a message last night and asked hin to confirm his response to your inquiry in order to help your recollect ion of your message to him.
Conveniently you posted the initial date of the thread containing John’s response (August 8, 2008) and not the date of the comment just before mine (January 9, 2009) or the delayed posting dates of my comment (Jan 18 , 2009). Note the close proximity of the dates of my comments and the initial date of the posting of this thread.
> There are two comments from you there, one of which where you can’t even spell your > own name right. “Gerlad”.
Oh give me a break.
Are my comments applicable to the results on this thread (whether or not I mistyped the spelling of my first name that has nothing to do with the quality of the comments)?
And did this thread suddenly magically appear even though on the thread where John’s
reply appeared there was no indication of a problem associated with the use of surface data in satellite temperature data retrievals (until my comments). And I pointed out that even the wikipedia site mentioned on the other thread stated there was a problem associated with satellite temperature retrievals.
Now you suddenly find that the reduction in GISS surface data sites has led to a divergence in satellite temperatures and GISS station data .
> You might want to work on that before you accuse me of deleting things or losing things. I >don’t answer things not addressed to me. You addressed them both to “Andrew” who >was also in the thread as another commenter.
So you don’t read scientific responses on your site even if they have a direct bearing on mistakes you have blatantly made. That is a convenient excuse. But in this case the sudden 180 degree turnaround in your approach to the topic leads me to believe that
this is not the case.
>Dr. Christy states in that thread that no surface data is used in the UAH MSU data >process. If you have something that says otherwise, I welcome you to share it. –
Did you read the wikipedia article or understand the results you have obtained on this thread? If the satellite temperature retrieval did not depend on surface temperature data, then a reduction in GISS surface sites would have no impact on the divergence of the two. And yet that is exactly what has happened.
Did I spell everything correctly?
Jerry
Anthony,
RSS evidently doesn’t use surface data – they evidently use climate model temperature profiles. What a hoot.
BTW I see you were reading comments not addressed to you on the other thread, because you asked for a reference in a comment addressed to someone else.
Any other statements you would like me to check?
I can provide a discussion of the problem of using radiances to retrieve temperatures based on tomography concepts. The problems are very similar and the common problem can be seen in the manuscript results posted on CA under the name Sylvie Gravel
(plus one additional comment I made on CA related to that manuscript).
Jerry