On the Divergence Between the UAH and RSS Global Temperature Records

Permanent Link to Global Temperature UAH-versus-RSS

By Dr. Roy Spencer

…or, OMG! HAS UAH BEEN BOUGHT OFF BY GREENPEACE!?

Over the last ten years or so there has been a growing inconsistency between the UAH and Remote Sensing Systems versions of the global average lower tropospheric temperature anomalies. Since I sometimes get the question why there is this discrepancy, I decided it was time to address it.

If we look at the entire 30+ year record, we see that the UAH and RSS temperature variations look very similar, with a correlation coefficient of 0.963 and linear trends which are both about +0.14 deg. C per decade:

(In the above plot I have re-computed the RSS anomalies so they are relative to the 1981-2010 average annual cycle we use; this does not affect the trends…just makes it more of an apples-to-apples comparison).

But if we examine a time series of the DIFFERENCE between the two temperature records, we see some rather interesting structure:

Read More Here

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Also, based on a conversation with Roy at ICCC and minor change in naming conventions, I am pleased to announce that Dr. Roy Spencer’s UAH Lower Atmosphere Temperature Chart is now available on WUWT’s Global Climatic History Page and Atmosphere Page.

If you really like to keep an eye on Atmospheric Temperatures it is recommended that you visit the University of Alabama at Huntsville’s Discover AMSU Temperature Page, which offers daily atmospheric temperatures from a range of heights based upon the Aqua satellite.

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49 thoughts on “On the Divergence Between the UAH and RSS Global Temperature Records

  1. I appreciate the integrity of the UAH dataset and really don’t care so much about the comparison to RSS. For me – its all about the comparison to the surface temperature record……

  2. The warmistas love UHA because it shows warming of late.. Unfortunately there has been no increase since 2002 (its flat), so no warming as stipulated by the IPCC. But at least the warmistas like to cite or trust it, so its actually very good news for the skeptical side as they (AGW) will not be able to whinge when and if it goes down

  3. HenryP

    The satellite record of 0.14C/decade is unlikely to be the long term trend as the whole satellite record is contained by the warm side of the Atlantic Multidecadal Oscillation (AMDO) and will be hit by the 30-year long cool side of the oscillation now. I believe the long term trend is only about half of that or 0.07C/decade and we can attribute maybe half of that to anthropogenic CO2, a tenth or two anthropogenic methane, and the last couple tenths to the modern maximum (solar activity). The real test is coming up what with the AMDO turning negative and the sun believed to be entering a grand minimum for a few decades or more. If we’re lucky it won’t totally eliminate the recent decades of warming because the warming has been quite beneficial for agriculture.

  4. Dr. Roy,

    Can you understand why many of us do not trust ANY of the data anymore? For one reason or another It appears to get bent, twisted, adjusted, by each agency, to suit their own agenda be they warmers, coolers or guys in between and then people who are not even good at statistics really go to work on it all!

    To be honest I think, on the whole, there are honest people working on the subject but you are all miles away from figuring how to get this chaotic system together before modelling graphs and telling me what is happening.

    You can throw all the formula you want at the data but you cannot even keep a satellite in the orbit without calibration to adjust for its drifting! Its all just guessing really.

  5. OT but the warmist will really be jumping on this one (even though temps have flattened). Could be lower than 2007 in which case the agenda will be pushed through and we will all be impoverished

    http://ocean.dmi.dk/arctic/icecover.uk.php

    Of course they will not mention Antarctica which has been above or normal for years now

  6. This comment from Roy Spencer says it all really

    But, until the discrepancy is resolved to everyone’s satisfaction, those of you who REALLY REALLY need the global temperature record to show as little warming as possible might want to consider jumping ship, and switch from the UAH to RSS dataset.

    It’s OK, we’ve developed thick skin over the years. You can always come home later

    Actually, Roy, I think you’ll find HadCrut is currently in favour – though it’s noticeable that RSS is making an increasing number of appearances on certain blogs (not this one).

  7. The real divergence is GISS from the others. These should open your eyes more than a cup of coffee:

    Part 1

    Part 2

  8. Latitude says:
    July 8, 2011 at 7:13 am

    Can we add .3 to it………….because CO2 is heavy?
    ==================================================
    Of course we can, and probably will when it becomes apparent the sat data isn’t matching our belief systems. lol

  9. “Pete H says:

    July 8, 2011 at 7:07 am

    Dr. Roy,

    Can you understand why many of us do not trust ANY of the data anymore? For one reason or another It appears to get bent, twisted, adjusted, by each agency, to suit their own agenda be they warmers, coolers or guys in between and then people who are not even good at statistics really go to work on it all!

    I think this is a very good point, and keep in mind that so much of this data is cherry-picked, flung around like dung as strawmen, and otherwise ignored if it does not show the truth as “some people think the truth is.”

    If that seems just a bit crypic, maybe its because it really is. Its not about what the temperature series(s) really say or do not say, its all about keeping the funding going for third-rate scientists or other people who sold their souls to the global warming band-wagon and really can not do anything else at this point.

    So yes, I would say at this point I don’t care if you use GISS or UHA or whatever series you want to. Because in the end, they are all corrected with statistics differently, and whether these corrections really correct things can be debated endlessly. Even the satellite data is “Corrected”…and when this is done, the trends are all changed. What are we the thinking people supposed to think? I just laugh at the end of the day at all the antics of the warmists with difference metrics. – IE we only use temp scales that show warming currently and forever.

    They have to use so many different series’s just to be able to continue to beat that old drum that its really funny now. They are becoming laughing stocks, and as much as I admire the science here and elsewhere, we have to realize at some point that fighting PMS is not going to work with real science. We will never win as realists/sceptics or whatever we want to call ourselves.

    The only thing we can do is to show how out-right wrong these people are. Until they work at McDonalds, keep a close eye on them, and especially on people who correct the data and put them under a microscope. At the same time , we need to show divergence issues such as this more. As sceptics, divergence problems are something common people can understand, kind of like the “hide the decline” which caused so much damage. One email did all of that to Dr. Mann, what kind of issues are we still missing?

    I would hazzard to guess Dr. Santer is worth a looking into at some point, he is after all the current scientist adjusting (correcting?) satellite data to show that maybe the satellite data is missing the hot-spot! What hubris! This from the same man who corrected the IPCC 1996 report to claim that yes, we found a human imprint in the climate!

    Oh so much to say, but I will leave it at that.

  10. Bob roege that’s well within normal deviation . Er temps are NOT rising and ice is melting OMG

  11. “Of course we can, and probably will when it becomes apparent the sat data isn’t matching our belief systems. lol”

    Yes the next few years will be interesting. People who clamor for the return to normal science will continue to ignore observations or question observations… IN THE SAME BREATH they will point to believers in AGW who ignore observations.

    People pick and choose the observations they happen to like. When all the observations go against their belief system… they

    1. Attack observers
    2. Question knowledge and prediction altogether ( its chaotic!)
    3. Point to what we dont know ( It could be another cause!)

    selective skepticism

  12. BTW re:polar ice caps: What happens if mean global temps fall to say 0 or below anomaly and NH ice melts completely (or say below 2007 minima) how will this be interpreted?

  13. Steven Mosher says:
    July 8, 2011 at 10:04 am

    “Yes the next few years will be interesting. People who clamor for the return to normal science will continue to ignore observations or question observations… IN THE SAME BREATH they will point to believers in AGW who ignore observations.”

    Steven, instead of pointing out our collective deficiencies, lets give Dr Spencer credit for scrupulous honesty. I think it can be said that although Dr. Spencer is a skeptic (to my perception at least), he does not fudge, and when he sees a discrepancy he investigates it. I am sure he will engage constructively with Mears and Wentz to address this issue and that they will by their efforts set an example for the rest of climate science to follow.

  14. Steven Mosher says:
    July 8, 2011 at 10:04 am
    People pick and choose the observations they happen to like. When all the observations go against their belief system… they
    ==========================================================
    Oh for the good old days…………
    When all you had to do was kill a chicken or throw a virgin in the fire………………

  15. NWS Monterey:

    500 MB HEIGHTS ARE EXPECTED TO BE MORE THAN -2 STANDARD DEVIATIONS FOR THIS TIME OF YEAR SO HIGHS WILL BE MUCH COOLER THAN NORMAL NORMAL FOR MOST OF NEXT WEEK. IN FACT MOST INLAND SPOTS WILL BE IN THE 65 TO 75 DEGREE RANGE BY NEXT WEDNESDAY (MID 50S TO LOW 60S AT THE COAST) AND COASTAL COMMUNITIES COULD GO MULTIPLE DAYS WITH VERY FEW BREAKS IN THE CLOUDS. COASTAL DRIZZLE IS POSSIBLE FOR MANY MORNINGS AS WEAK IMPULSES ASSOCIATED WITH THE TROF ROTATE THROUGH.

    ===============================

    Each update this seems to be strengthening. Will it ultimately be an actual rain producing mid latitude (as opposed to tropical or SW Monsoon) system? In mid summer … in California.

  16. Pochas, if you go to the good Dr’s. blog you will see that Dr. Mears has posted there.

  17. I’ve asked this before but I don’t think it was in the context of satellite measurements. As more parts of the world develop and industrialise will there not be an increase in the amount of DIRECT warming of the atmosphere by human activity? By “direct” I mean the warmth given off by the burning of fossil and nuclear fuels, which is used for residential heating, transport, industry, power generation, and so on, but which which must eventually leak out into the environment. Could direct warming be large enough to be detected by the satellites? Has anyone tried to quantify it?

  18. Steven Mosher says (July 8, 2011 at 10:04 am): “People pick and choose the observations they happen to like. When all the observations go against their belief system…”

    Tell me about it. The last century’s “unprecedented” warming isn’t, the “endangered” polar bears aren’t, our “increasingly disrupted” weather isn’t, and fuel-saving “green energy” doesn’t, but hey we’re still gonna DIE!!! if we don’t mend our ways!

    In a way, I really wish humanity did have its collective hand on the earth’s thermostat, because I don’t care much for the current setting — a bit too chilly. Unfortunately the earth is a lot like my own house, where my wife controls the thermostat and I…don’t.

    Grrrr.

  19. SJF says:
    July 8, 2011 at 12:27 pm

    Yes, the amount of direct heat from human processes has been quantified, and it is still insignficant. A year or two ago, I came across a paper that looked at this. They did an exponential extrapolation of human energy use and conclude that after 7 more doublings (128 times increase), the amount would start to be noticeable in the global climate system.

  20. SJF says:
    July 8, 2011 at 12:27 pm
    I’ve asked this before but I don’t think it was in the context of satellite measurements. As more parts of the world develop and industrialise will there not be an increase in the amount of DIRECT warming of the atmosphere by human activity? By “direct” I mean the warmth given off by the burning of fossil and nuclear fuels, which is used for residential heating, transport, industry, power generation, and so on, but which which must eventually leak out into the environment. Could direct warming be large enough to be detected by the satellites? Has anyone tried to quantify it?

    Per Wikipedia, solar irradience it 3,850,000 exajoules per year. Human energy consumption (2005) is 487 exajoules per year. The earth receives the human energy budget in approximately 1 hour. The natural variation is 3.5%, so plus or minus 134,750 exajoules. The human contribution to direct warming doesn’t even qualify as noise.

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

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

  21. I wrote: “I’ve asked this before but I don’t think it was in the context of satellite measurements…” Apologies, as I’ve now found the thread where I asked about “direct” warming of the atmosphere before (i.e. no need for CO2 / greenhouse effect) and it WAS in the context of the satellite record. I do still wonder why this effect is not talked about more as a possible contributor to or even cause of the observed warming trend. On the previous thread, commenter ‘pft’ answered my question thus:-

    “Hoyt (2006) indicated the US generated heat at about 0.34 W/M2, about 1 W/M2 in urban areas and much higher in cities. For this reason you would believe satellites are much better than surface temperature stations, at least 1/2 or more are in urban areas. Of course, land accounts for only 29% of the globes surface area.

    “He estimated that since 1900 a population increase of 1 billion to 6 billion could account for 0.5 deg C, which is close to the observed warming. Of course, it’s complicated by land useage changes, aerosols, more active sun, and of course more CO2, etc.

    “Thats from David Rapps book on Assessing Climate Change”

  22. Steven Mosher says: July 8, 2011 at 10:04 am
    …the next few years will be interesting.

    Don’t see why.
    CO2 is already running out of ‘gas’, the ‘grand sunspot minimum’ will turn out be a climatic damp squid, warmers fading into background and deniers left with not much to deny.

  23. GISS/NASA is a Green Gang front god-fathered by the notorious James Hansen, he of the $1.2-million emolument scraped together while supposedly a Devoted Public Servant (DPS). Research? Science? Puh-leeze! DIPS are in charge, that’s all we need to know.

  24. Vuk.

    I realize your a voice in the wilderness that no one is listening to. At some point, perhaps it will occur to you that there is a reason for that. And it won’t have anything to do with other peoples lack of understanding. Instead, quite the opposite.

  25. gary:

    “Tell me about it. The last century’s “unprecedented” warming isn’t, the “endangered” polar bears aren’t, our “increasingly disrupted” weather isn’t, and fuel-saving “green energy” doesn’t, but hey we’re still gonna DIE!!! if we don’t mend our ways!”

    yes, it’s true the CAGw crowd says all sorts of silly things. There is no need to copy them

    There is a epistemological lemming effect.

    back in 2007 the warmists starting screaming about the ice. My advice to them was this:

    “the ice melts for many many reasons. The ice melt is not the BEST evidence for AGW,
    so please do not run for the ice”

    And of course skeptics follow them in debating evidence that is really not central to the case.
    espistemological lemmings.
    Then of course there are the other debates, debates over “unprecedented”. Again, weak evidence that you dont want to hang your hat on.. either FOR the case or Against the case.

    And now with the sun. all manner of people who should be skeptical are saying definitive things.
    So much for rigorous thinking.

    It’s fun to watch.

  26. Steven Mosher says:
    July 8, 2011 at 10:04 am

    1. Attack observers
    2. Question knowledge and prediction altogether ( its chaotic!)
    3. Point to what we dont know ( It could be another cause!)
    selective skepticism
    ===========================================================
    Indeed. Though, in this case, while # 1 would be an indication of “selective” skepticism(and silliness given the history of Dr.s Spencer and Christy), I think it fine and rational to both question the knowledge and show what we don’t know. Given the large degree of variance between RSS and UAH, and the professional disagreement as to why…..(see here for Carl Mears’, of RSS, comment. I would say your #s 2&3 would by symptomatic of healthy skepticism.

    To view the divergence, see here.

    While the divergence may not appear to be significant, in this context(a decade), +/- 0.1 degree is huge.

    On an aside, given what I’ve recently seen about satellites, I’ve little expectation that they could be much closer than that.

  27. SJF says:
    July 8, 2011 at 12:27 pm

    do you mean in energy terms? if so its something like 174 Petawatts of energy incoming from the sun (1.74×10^17 W) and human energy use is 16TW or 1.6×10^13 W. Estimated actual surface solar energy reaching earth is 8.9×10^16 W – or in round figures 5000 times the human energy production?
    so in terms of heating the planet directly – no, I don’t think human energy use is important!

  28. Steven Mosher says:
    July 8, 2011 at 3:39 pm
    It’s fun to watch.
    =================================
    So how’s the climate way up there…..above it all

  29. @Mosh
    you are right in pointing out the deficiencies in either side pinning their hats on any single piece of so called evidence.
    true skeptics dont believe a word of anything, unless they can see it/do it/ test it for themselves! But the trouble is that the AGW theory and its political agenda has been force fed to us for soooo long that the skeptics will naturally want to jump at any chance to knock the concensus.
    when the data is collected and ready it hopefully will tell us what we need to know – but in the meantime, everyone MUST remember to point out what it currently DOES tell us – and that is that we do not KNOW it all – and the CONCENSUS was/is almost certainly based on incomplete data and understanding and moreover, any crazy ideological actions based thereon could be more risky than cautious action.
    What annoys me the most about the whole AGW argument is the tipping point/alarmist scenarios – which we know from geological history – must be complete twaddle! If the warmists were saying – ‘yeah man, CO2 is probably warming the planet – lets ease off a bit and see what gives’ – I could go along with that kind of attitude, I might not agree, but it’s the pragmatic approach. But the gung ho, ‘Cut everything because the planet’s gonna die in a few years’ alarmism just don’t make sense and worse still, when the (false) alarmism is exposed as easily as in AR4 – it is gonna make everyone loose faith, the boy who cried wolf to often and all that! If the warmists had been a little less keen to be ‘groundbreaking’ and seeking fame in the media – this debate would never have got to the crazy warmist/denialist stance we know have.

  30. Steven Mosher says (July 8, 2011 at 3:39 pm): “Then of course there are the other debates, debates over “unprecedented”. Again, weak evidence that you dont want to hang your hat on.. either FOR the case or Against the case.”

    Actually, I consider the “precedented” argument to be the strongest against the CAGW bogeyman. Current temperatures, sea level, CO2, weather, etc. are all “precedented” in the earth’s history and yet life thrives. All the “evidence” for incipient CAGW is theoretical, yet there’s theory against it, too (e.g. no detectable tropical tropospheric “hot spot”, and differing estimates of “climate sensitivity”). So with uncertain theory and no physical evidence, I see no need to take drastic measures (with definite negative consequences) against a decidedly indefinite “threat”. The best course is to push the economic growth and scientific advancement that will improve our ability to deal with ANY future threats, e.g. asteroid collisions, solar (in)activity, and global cooling/heating.

    Just so we’re clear, what do you consider the strongest non-silly things the “CAGW crowd” says?

  31. Steven Mosher says:
    July 8, 2011 at 3:32 pm

    Vuk.

    I realize your a voice in the wilderness that no one is listening to. At some point, perhaps it will occur to you that there is a reason for that. And it won’t have anything to do with other peoples lack of understanding. Instead, quite the opposite.

    No effing way you were an English professor.

  32. Steve Mosher @ several
    Whilst I appreciate that skeptics can and do get carried away in the moment when arguing the toss over all things CAGW, THEY did not set the agenda in the debate (alarmists did). THEY did not attempt to indoctrinate masses of the global population in an extremist ideology that has more to do with cultist behavior than anything representing analytical thought! You project your own self perpetuating belief system onto all sides of the debate except your own. We are ALL subject to the constraints of our own egotism, yourself included, which no ivory tower intellectual viewpoint can hide. Your expertise is clearly of a extremely high level, far higher than mine for example, but it is important to realize that we are all fallible and can view data with the “eye of faith”, including lukewarmers like yourself. The onus of proof remains wholly and completely in the hands of alarmists who are asking us to radically transform the economic and geopolitical landscape predicated on very weak evidence with error bars almost as high as the level of warming seen. Remember the total surface temperature warming is less than 3/4 of a degree in almost 150 years. No need for any drastic measures, radical wealth redistribution or massive increase in taxation. NONE.

  33. So, what is the theoretical or rational basis for approximating any trend of any type on the satellite temperature record as any kind of a straight line?

    There is a 60-66 year short climate cycle that predictably varies measurable global temperatures by 0.25 degrees, superimposed on a longer 900-1000 year cycle (Roman Warm Period, Medieval Warm Period, Modern Warming Period…. We don’t know the theoretical reason behind either cycle (yet!) but they are demonstrable and repeatable across all records and all proxies at locations all over the world.

    So, go back to the figure: Why is a slowing rising sine wave not projected on the graph? It is what is observed after all. (Near flat in 1980 since it was rising from the mid-1970’s when the record begins in 1978-79, then rising until its high point as a flattened curve across the peak from 2000 – 2010.) Why is a linear trend extrapolated when one does not exist?

    Longer term, still to be determined, is whether the Modern Warming Period will peak in 2000-2010, or 60 years later between 2070 – 2080, or still one cycle later between 2140 – 2150.

    Mendeleev did NOT know the theoretical basis for any part of the Periodic Table when he used it to predict future elements, future element properties not yet measured, and even found errors in experimental results that not match the Table properties. Newton could not develop the theoretical Laws of Gravity – but he used what was actually observed to develop the practical laws of physics. That list could be continued, but i predict that no real understanding of the earth’s climate will occur until the first man or woman is courageous enough to stop drawing straight lines, and begin to explore why there are periodicies in the real world.

  34. Jeff Alberts says:
    July 8, 2011 at 7:54 am
    LearDog says:
    July 8, 2011 at 4:42 am
    I appreciate the integrity of the UAH dataset and really don’t care so much about the comparison to RSS. For me – its all about the comparison to the surface temperature record……
    It’s too bad that neither one is giving us useful information.

    Jeff;
    Thanks for that. Walking my way thru, and enjoying the clarity and rigor.
    One of many take-aways:

    If there is no preferred coordinate system given for the average because the physics does not provide one, then any value in the data set can stand as an average of the temperature field.

    In lay-speak, the “true” average of a list of temperature measurements can be whatever you want; there’s no choosing by physical criteria. I.e., it’s meaningless.

  35. HenryP says:
    July 8, 2011 at 5:26 am

    Well, the 0.14C increase per decade is in line with what I find: 0.13C per decade.
    What those sat. records do not show is what caused the warming.
    Either the sun shone a bit brighter or there were less clouds.
    —————————————————————————
    AND OR,OUT OF SIGHT,OUT OF MIND,3 MILLION +++ submarine thermal vents volcanic activity AND
    SEISMIC that ALL show several hundred percent INCREASE,Professor Ian Plimer WILL prove to be correct and vindicated soon and george moonbat will be forced to apologize to him.

  36. Kev-in-Uk says:
    July 8, 2011 at 4:11 pm


    If the warmists had been a little less keen to be ‘groundbreaking’ and seeking fame in the media – this debate would never have got to the crazy warmist/denialist stance we know have.

    And here’s where the “it’s just science” and “it’s fundamentally a power-grab” POVs part company. The direness of the predictions and extrapolations and implied necessary remedies are CORE, not derivative. It is not desire to “scoop” the science community that drives the (C)AGW bus.

    Edits: It’s “consensus”, and “lose faith”, not “concensus” and “loose faith”.

  37. Brian H says:
    July 8, 2011 at 8:54 pm

    agreed – I wasn’t trying to suggest the current crop of pro-AGW climate scientists or their warmist agendas are in any way interested in ‘Saving the Planet/Humankind’ or anything these days as their driving force! For them it seems to be all bravado and hot air on the most part, or simply trying to get recognised as some kind of ‘expert’ in the MSM. I suppose, perhaps 20/30 years ago, someone in the climate field may just have shown some genuine concern, but within a short time the political agenda input must have been introduced (along with all the funding of course!).
    BTW, apologies for typos – it was the last thing I did before hitting the sack!

  38. I am not a denier of any objective measure of what is going on with the Earths climate ,there are always different ways of measuring anything.I am not a denier because I refuse to accept the political interpretations made by the left and right about “climate change”.Governments would like to make a set of rules of how we should all behave with regard to the Earth’s changing climate and this is similar to the rules of economics which have been imposed on us by Governments over the years.Left or Right economics?We can criticise both the rules of the “free market” and “Socialism” they are not the natural order of society that both claim to be.I think that the Earths climate should be left to the scientists to study and we should not have Governments or the UN involved in “climate change”.

  39. Steven Mosher says:
    July 8, 2011 at 3:32 pm
    Vuk. I realize your a voice in the wilderness that no one is listening to.

    Hey Steven
    In your consciousness: Bee Gees or prophet Isaiah ?
    In your world of climate science: Fool’s false hope or wise man’s depths of despair ?

  40. Isn’t it about time that we stopped chasing degrees around the world and averaging them? As someone said, it’s about as useful as averaging the phone book to get the next number to call.

    Temperature averages for the MWP or LIA according to some ‘authorities’ vary scarcely from ‘noise’ yet the effects of these periods had very real and sometimes disastrous consequences for many populations around the world from drought , rain and cold such as we have never seen.

    Incursions of the Polar Jet Streams close to, or beyond the equator have occurred in the southern hemisphere over the past two years and moved further south than normal in the NH. These are signs of a cooling climate, which consists of increased weather extremes according to the father of modern climatology Hubert H Lamb (whose Christian name I got wrong in a previous post, by quoting from “The Hunting Hypothesis”)
    An internal CIA paper on the effects of a cooling climate can be seen here,

    http://www.climatemonitor.it/wp-content/uploads/2009/12/1974.pdf

    which makes interesting reading some 36 years on. Perhaps they got the timing wrong, but will the consequences be much different if they are right about cooling this time?

  41. Henry@Barry Day

    I don’t have a problem with adding the probablity that volcanism did play a role in the warming of earth. But, like GHG warming, it looks difficult to prove.

  42. Are you trying to tell me that those two graphs are different ? If the climate outcome depends on the difference in those two data sets, then we are all doomed.

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