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The global temperatures.

  1. Nov 20, 2008 #1
    Let's compare the four predominant data sets about the global temperature updated to include October 2008:

    Shown in thin lines are the monthly averages while the thick lines represent 12 months running averages.

    Red and orange are based on surface meteo station data as compiled by NASA (Hansen et al) and the British Met Office (HADCRU of Jones et al). Green and blue are two different products of the same satellite data series compiled by University of Alabama (Spencer et al) and Remote Sensor Systems (RSS).

    See how NASA creeps up, whereas Jones et al of the UK met office holds the midgrounds between Hansen and the two satellite temperature sets. Although the latter show differences in monthly values, both have a robust fit of the 12 months running mean (bold black).

    How would this compare to the predictions from the past?

    sources

    http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts+dSST.txt
    http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/monthly
    ftp://ftp.ssmi.com/msu/monthly_time...hannel_tlt_anomalies_land_and_ocean_v03_2.txt
    http://vortex.nsstc.uah.edu/public/msu/t2lt/tltglhmam_5.2[/
     
    Last edited by a moderator: Dec 31, 2008
  2. jcsd
  3. Dec 29, 2008 #2

    Xnn

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    One of the obvious differances is that the University of Alabama series is not of the surface. It is measuring the lower troposphere, a shifting target.

    Another observation is that ENSO adds considerable noise to the system and of course the oceans have much more heat capacity.

    There is also the National Climate Data Center series. Here is a graph of their data:

    [​IMG]
     
    Last edited by a moderator: Dec 30, 2008
  4. Dec 29, 2008 #3

    Ivan Seeking

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    Are you asking for amateur interpretations of data, which amounts to asking for personal theories, which are not allowed here?

    What are the peer-reviewed interpretations of this data?
     
  5. Dec 29, 2008 #4

    Evo

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    If it's based on the data from the official sources posted, what is wrong with that? Are you saying members aren't allowed to comment on legitimate, official data?
     
  6. Dec 30, 2008 #5

    Ivan Seeking

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    Most members aren't qualified to comment. The appropriate thing to do is to at least see what the real experts have to say, first. At least that way we know all of the variables that are considered.

    It would be do-it-yourself [crackpot] science for amateurs to engage is an analysis. And if someone wants to take a respectable shot at this, we have the IR forum for that.
     
  7. Dec 30, 2008 #6

    Evo

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    It's not an "analysis" of the data. It's looking at what these "official" sources predicted would happen as opposed to what actually happened. Like "it will rain Thursday" and on Friday you know it didn't rain Thursday.
     
  8. Dec 30, 2008 #7

    Monique

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    He's asking how the data compares to the predictions from the past. Of course the predictions (as well as the data) need to be from a credible source, otherwise it is not even worth discussing.
     
  9. Dec 30, 2008 #8
    That's the spirit of the scientific method, testing the predictions, and that's the intention of this post, to see if it rained on Thursday. No analyses, just comparing predictions with measured results.

    This is the prediction that started the global warning alarm Hansen et al 1988, centered around the model result, fig 3 (page 9347)

    So what happens if we merge the actual results of the NASA and RSS (12 month running average) with the predictions:

    Note that the vertical positions of the graphs depend on different definitions of the basic zero value. Therefore I have displaced the vertical plots of the both measured series to start at the average value between scenario A and B.

    Also important is to note the presumptions for the about the three scenarios in appendix B page 9361 - 9362

    So the next question is, which scenario is closest to reality.
     
    Last edited by a moderator: Dec 31, 2008
  10. Dec 30, 2008 #9

    Astronuc

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    Perhaps it's still too early to tell. The NASA 12 Mo RA and RSS 12 Mo RA oscillate quite a lot compared to the models, which seem smoother. Occasionally the measurements depart from the models. It's hard to tell A, B, C (but I assume C is the bottom one in the second plot). It would appear the measurements are dropping below C between 2006 and present.
     
  11. Dec 30, 2008 #10

    Monique

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    How are standard deviations or confidence intervals normally taken into account with these types of models and data?
     
  12. Dec 30, 2008 #11

    Astronuc

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    Perhaps those details are buried in the papers by Hansen et al., e.g. the one cited by Andre in post #8.

    I suppose they could use noise analysis. In some cases, I seen 5-year (rolling average) trending plots which smooth out variations. I'm not sure how the measured data are processed.

    Hansen/GISS make the following comments:

    Ref: http://data.giss.nasa.gov/gistemp/

    And with respect to 2008, GISS offers the following:

    A press release from Met Office Hadley Centre and the Climatic Research Unit (CRU) at University of East Anglia
    2008 global temperature
    Plot of temp anomaly by rank - http://www.metoffice.gov.uk/corporate/pressoffice/2008/images/latest_rankings_jan_to_nov.gif

    2008 ranks as tenth warmest in the set for the period considered.

    Variability (transient processes) on the order of ~.2-0.4°C seems to be expected.


    Hadley Center paper on uncertainties - http://hadobs.metoffice.com/hadcrut3/HadCRUT3_accepted.pdf


    MSU/AMSU atmospheric temperature products.
    Changes from RSS Version 2.1 to RSS Version 3.0 (pdf - use 'save target as')

    and

    Construction of the Remote Sensing Systems V3.2 atmospheric temperature records from the MSU and AMSU microwave sounders.
    http://www.ssmi.com/data/msu/support/Mears_and_Wentz_TMT_TTS_TLS_submitted.pdf
     
    Last edited: Dec 30, 2008
  13. Dec 30, 2008 #12

    Xnn

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    Hansen papers assumes in scenario A and B that CO2 emissions will grow 1.5% annually. Actual atmospheric CO2 concentrations have been growing only about 0.4% annually since 1980 for a total of 13.6%. Hansen also assumes a climate sensitivity of 4.2C per doubling of CO2.

    Since 1980, according to the NCDC data base, global 5 year average temperatures have risen about 0.51C, whereas NASA GISS finds 0.53C. Considering the actual increases in CO2, Hansen’s sensitivity assumption works out to 0.57C of warming. So, actual climate sensitivity to CO2 doubling looks to be less than 3.8C since CH4 has also played a role (at least up to the 1990's).

    Hansen should have assigned an uncertainty band for his CO2 sensitivity or anticipated solar irradiance falling as much as it has. On the otherhand, perhaps he seriously underestimated climate sensitivity to CH4. Go figure.
     
    Last edited: Dec 30, 2008
  14. Dec 30, 2008 #13

    Gokul43201

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    Why am I not surprised? Another thread that seems to be based on misinformation and fallacious arguments.
    Umm... NASA (GISTEMP) does NOT "creep up", nor does the UK Met (HADCRUT3) hold a middle ground between GISTEMP and the LT dataset.

    In fact, if you take the littlest trouble of adjusting for the baselines, one will find that 3 of the 4 datasets match fairly closely. The outlier is the UAH set, (not GISTEMP, as anyone reading any number of the threads in this forum - including this one - would have come to believe).

    Here's what you'd get for the means and trends of the 4 datasets (from a linear least squares fit to 12-month running averages from last 30 years of data) after correcting for the baselines by using the 1979-1998 mean values (which RSS and UAH use) for all four sets:

    GISTEMP: mean anomaly = 0.082C, trend = 0.16C/dec
    HADCRUT3: mean anomaly = 0.080C, trend = 0.16C/dec
    RSS: mean anomaly = 0.081C, trend = 0.16C/dec
    UAH: mean anomaly = 0.065C, trend = 0.13C/dec

    If anything, it looks like UAH is the outlier, not GISTEMP (NASA)!

    Please check these numbers for yourself and let us know if you get something different.

    And oh yes...
    That's just flat out ridiculous!

    UAH and RSS do not share the same indistinguishable 12-month running average. In 1980, for instance, the difference in the 12-month average is nearly 0.1C (after matching almost exactly in 1979). Whoever made the plot in the OP will need to make that "bold black" line about 20 times thicker in order to pull off the story that UAH and RSS share the same running mean for every month of the last 360 months!

    As I've said above, they do not even posses closely matching trends.
     
    Last edited: Dec 31, 2008
  15. Dec 31, 2008 #14
    Indeed I made a mistake, using the same UAH data twice for the 12 month running average in the OP giving a RA slightly above UAH. I should have more cautious because it's meaningless and has nothing to do with misinformation. UAH is indeed the outlier with the lowest trend, however NASA is the only of the four not having 1998 as the warmest year which results in an optical outlier.

    The second graph in my last post does not suffer from that error because it has been generated differently, calculating the running average from the correct data manually

    for scrutiny:
    http://rapidshare.com/files/178377031/the_big_tempfile-3.xls
     
  16. Dec 31, 2008 #15

    Gokul43201

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    Well Evo, I guess this answers your question: "If it's based on the data from the official sources posted, what is wrong with that?" The plot in the OP was NOT a true representation of the data from the official sources! I guess that leaves Ivan's question unanswered.

    UAH is the only of the four that has 1980 as the warmest year in the 1979-1987 period. Does that make UAH an optical outlier?

    What is an "optical outlier"?

    Is a judgment of the quality of a dataset based on one single "optically" chosen year of any real scientific value?

    Can we please stop scapegoating NASA (or anyone else, for that matter) with hand-waving "optical" arguments?
     
  17. Dec 31, 2008 #16

    Evo

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    But the links to the official sources are valid, so what I said stands.
     
  18. Dec 31, 2008 #17

    Gokul43201

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    Then can we please delete all the plots that are not copied from published papers (such as the one in the OP, which we know is wrong), as well as any description of such unverified plots?
     
  19. Dec 31, 2008 #18

    Evo

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    Yes, that's a good idea.
     
  20. Dec 31, 2008 #19

    mheslep

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    Note that while that may be be correct for concentration, CO2 emissions did increase as Hansen assumed and more: 28% from '90 to '04, peaking at 5% in 2004. Thus Hansen's '88 accumulation model was flawed:
     
  21. Jan 6, 2009 #20
    There is no such thing. The temperature is defined for a system in (cvsi)equilibrium.
    That's it. The "global temperature" the statisticians talk about is something else than a "temperature" (that is, a system parameter, a physical property, blablabla). It's not something that has a physical meaning. It should be named bull...rature, to avoid equivocation.
     
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