By Steve Goddard
There has been an active discussion going on about the validity of GISS interpolations. This post compares GISS Arctic interpolation vs. DMI measured/modeled data.
All data uses a baseline of 1958-2002.
The first map shows GISS June 2010 anomalies smoothed to 1200 km. The green line marks 80N latitude. Note that GISS shows essentially the entire region north of 80N up to four degrees above normal.
The next map is the same, but with 250 km smoothing. As you can see, GISS has little or no data north of 80N.
Now let’s compare the GISS 1200 km interpolation with the DMI data for June 2010.
Daily mean temperatures for the Arctic area north of the 80th northern parallel, plotted with daily climate values calculated from the period 1958-2002.
http://ocean.dmi.dk/arctic/meant80n.uk.php
DMI shows essentially the entire month of June below the 1958-2002 mean. GISS shows it far above the the 1958-2002 mean. Yet GISS has no data north of 80N.
Conclusion : GISS Arctic interpolations are way off the mark. If they report a record global temperature by 0.01 degrees this year, this ↑↑↑↑↑↑↑ is why.
——————————————————————
Straight from the horse’s mouth.
the 12-month running mean global temperature in the GISS analysis has reached a new record in 2010…. GISS analysis yields 2005 as the warmest calendar year, while
the HadCRUT analysis has 1998 as the warmest year. The main factor is our inclusion of estimated temperature change for the Arctic region.
– James Hansen
In other words, the GISS record high is based on incorrect, fabricated data. Why did Hansen apparently choose to ignore the DMI data when “estimating” Arctic temperatures? GISS Arctic anomalies are high by as much as 4 degrees, and yet he claims a global record measured in hundredths of a degree. As Penn and Teller would say …. well I guess I can’t say that here.
The common theme being presented here is that the high arctic is much colder than the GISS data would lead you to believe. The statement given in a prior thread that the area is “frozen solid” and, by implication in the graph above, that little or no melting occurs below 273.15 K, should be met with some skepticism. Watch the movie in the link below, from the North Pole PAWS buoy, and judge for yourself.
http://www.arctic.noaa.gov/np2010/cam2-2010.mov
The Northern Cryosphere continues to lose ice at an alarming rate and will likely reach a minimum this year that is well below the 1979-2000 average. The vagarities of different Global Warming temperature analyses, although all are in very close agreement, will not alter this eventual outcome.
Just take temperature measurements where they are. Don’t adjust them and just look at how they change over 160 years. Make no pretence that you can construct a global average temperature. What you measure is what is happening. Why it’s happening and what will be the consequence is a guessing game. I’ll admit that CO2, the sun, aerosols, earths magnetic field, urban heat islands, CH4 etc etc have an influence on climate but whether it will prove dangerous is a guess. I’m now totally fed up with pundits pontificating on what will happen…they are like snake oil salesmen. And when it comes to using these pontifications to determine global energy policy I despair.
H.R. says:
July 28, 2010 at 9:32 am
DL says:
July 28, 2010 at 7:13 am
“Steve,
The link to GISS say’s June 2012 instead of 2010.
Unless they are making these maps 2 years ahead of time.”
If you’re making it up, does it matter which year it’s for?
===============
How lucky we are that AGW “scientists” practice pure science.
They did not mak it up 😉
http://whatreallyhappened.com/WRHARTICLES/globalwarming2.html
Steve:
You keep saying that DMI has buoys north of 80º. Could you point me to where you’re seeing this fact? I haven’t seen it indicated anywhere.
Frederick Michael says:
July 28, 2010 at 9:37 am
What’s up with all the nervousness about the use of the word, “model”? Apparently, that word is commonly used for any averaging or smoothing technique. Sometimes common usage of English is imperfect but still useful for communication.
If DMI uses buoys in the Arctic to measure temperature while GISS only uses land based stations, the DMI data (and their “modeling” of Arctic temps) should be superior, since the Arctic is mostly ocean.
You can’t refute this by nit-picking someone’s use of the word, “model.”
————Reply:
My intent here is not to be insulting, but I’m certain you know nothing about “modeling”. As a geologist I’ve used modeling on everything from geochem samples to grade-control blastholes to deposit reserves (and I did this for more than 20 years). The latter results I fed into stochastic valuation programs (another form of modeling) that measures parameter sensitivities, among other things. And I could make these models say practically anything I wanted (even if the data was factual), especially if I had an agenda.
So models are grand and models are tools but models are not necessarily a smaller or virtual version of reality. Quite often models are someone’s grandiose projection and are worse than erroneous data because the methodology easily allows hidden deception.
“The question is ‘why is the difference so significant?’ GISS shows June temperature anomoly as +4C higher,…”
I don’t know; maybe it’s because DMI is estimating the temperature of the sea and GISS is estimating the temperature of the air.
James Sexton says:
July 28, 2010 at 9:12 am
“What makes you think they use 1200 km smoothed data when the calculate the temperature?”——–Answer, because they said they do.
You linked back to a graph of 1200km smoothing. Goddard makes the argument that the global record, if a new record is set, will be the result of said smoothing and interpolation over 80 north, (and I suppose 80 south as well). What I’m asking for is some indication that the calculations used to arrive at the global mean are using data from the 1200km smoothing rather than the original data used to produce that smoothing. You haven’t provided that any more than Goddard has given us a calculation showing what the result would be without the model-generated data.
Goddard,
a consensus among the same geologists who believe in the blague hypothesis but then say CO2 can’t effect climate on short time scales?
Either way. This article may be interesting but you have to consider that the UK met office has already shown that warming is greater in the north than predicted by CRU and perhaps making it closer to GISS
http://www.metoffice.gov.uk/corporate/pressoffice/2009/pr20091218b.html
I mentioned this on another posting, but I’ll mention it again. DMI is based on a numerical model that assimilates whatever real observations are available into it’s forecasting model, and it will include rawinsonde and satellite observations when possible. It is not the same thing as comparing the interpolated surface temperature observations from surface stations in GISS. The forecasting model is the ERA-40 (you can find this out by going to DMI’s website).
From Peter Thorn at the Met Office:
Reanalyses are numerical weather-prediction systems run in hindcast
mode considering all globally available observations. Strenuous
efforts are made to take account of both time-varying biases in the
data and the impacts of the very substantially changing mix and
coverage of observations. However, many aspects of the long-term
behaviour of reanalyses remain unreliable and their suitability for
use in monitoring atmospheric temperature trends has been questioned
by a recent expert panel.
In addition, studies have shown that:
(1) data from satellites and weather balloons indicate that the ERA-40 trends
are increasingly unrealistic polewards of 62 N;
(2) that the other reanalyses datasets exhibit very different polar trends; and
(3) that the vertical profile of polar trends in ERA-40 is unrealistic, particularly
above the troposphere.
EFS_Junior says:
July 28, 2010 at 8:47 am
One metric (DMI) uses air temperature over the ice, while the other metric (GISS) uses SST under the ice.
Reading through all the comments, DMI uses bouys in the Arctic ocean (over the ice) and GISS uses land based stations stretching out 1200km into the ocean.
stevengoddard says:
July 28, 2010 at 9:31 am
“It is trivial to prove that the GISS data is wrong and the DMI data is correct. If temperatures at the North Pole really were 4C above normal in June, the ice would have been melting like crazy. ”
Interesting, average temp for the north pole is around 0 C in July. Recently, it is +11, (Well , that’s in the camera, which could be above ambient air, but then, in is cloudy.) and I do see meltwater in the view.
http://www.arctic.noaa.gov/latest/noaa2.jpg
My don’t we have a lot of trolls in today. Must be the hockey stick thread over at RC that’s got them all lashing out.
DMI says its cold, giss says its four degrees warmer than it “should” be. Is it, is it really?
Of course not or the arctic would be slush.
How much of the Earth’s surface is at 80°N or above? Sine 80° = 0.985 so that means 1.5 % of the Northern hemisphere is above 80°N or more appropriately 0.575% of the Earth’s surface area.
BTW extrapolation over 1000km is a proven technique that has stood the test of time since the 1980s: http://pubs.giss.nasa.gov/docs/1987/1987_Hansen_Lebedeff.pdf
I forgot to add that Poleward of 80N there is very little in situ data available to constrain the model. You don’t have many rawindsonde’s that far north, and satellite angles are off-nadir. There have always been problems with the surface data in reanalysis because of very little surface data available, so if you’re doing to look at temperature trends from reanalysis datasets, it is best to look at air temperature at 925mbars since studies have shown those to be more accurate than at the surface level.
Oops that should be 0.75%
Steve: You use the term interpolate for GISS Arctic data. Yet appears that GISS is extrapolating. Which is it in your opinion?
Can you explain your use of terms in light of the New Oxford Dictionary definitions below:
“interpolate |inˈtərpəˌlāt|
verb [ trans. ]
insert (something) between fixed points : illustrations were interpolated in the text. See note at insert .
• insert (words) in a book or other text, esp. in order to give a false impression as to its date.
• make such insertions in (a book or text).
• interject (a remark) in a conversation : [with direct speech ] “I dare say,” interpolated her employer.
Mathematics insert (an intermediate value or term) into a series by estimating or calculating it from surrounding known values.”
“extrapolate |ikˈstrapəˌlāt|
verb [ trans. ]
extend the application of (a method or conclusion, esp. one based on statistics) to an unknown situation by assuming that existing trends will continue or similar methods will be applicable : the results cannot be extrapolated to other patient groups. | [ intrans. ] it is always dangerous to extrapolate from a sample.
• estimate or conclude (something) in this way : attempts to extrapolate likely human cancers from laboratory studies.
• Mathematics extend (a graph, curve, or range of values) by inferring unknown values from trends in the known data : [as adj. ] ( extrapolated) a set of extrapolated values.”
Thanks.
Any use of reanalysis products, or products such as GISS needs to take into account the limitations of each data set. And given the differences in availability of data sources over the ERA-40 data record, it would be best to use the data from 1979 onwards when the satellite data record was assimilated into the ERA-40 model so at least ther.e is some consistency in processing. Biases will be introduced by inconsistent availability of in situ data throughout the data record.
Steven Goddard:
So, how many actual temperature measuring points does DMI have above 80N?
comparing the 2 globes, you can see a nice blockish structure to the 250 km version.
One would expect to see even more obvious blocks with the 1200 km version, but you don’t. There’s some kind of smoothing that creates gentle curves. Which also serves to mask the sparseness of the data, imo.
Julienne,
If temperatures at the North Pole had of been between 3-5C during June – as GISS seems to be implying – what would that have done to the ice there?
Jim G
I see only one active site north of 80N
Nord Ads 81.6 N 16.7 W 431043120000 rural area 1952 – 2010
http://data.giss.nasa.gov/cgi-bin/gistemp/findstation.py?datatype=gistemp&data_set=1&name=&world_map.x=274&world_map.y=25
GeoFlynx says:
July 28, 2010 at 10:15 am
The common theme being presented here is that the high arctic is much colder than the GISS data would lead you to believe. The statement given in a prior thread that the area is “frozen solid” and, by implication in the graph above, that little or no melting occurs below 273.15 K, should be met with some skepticism. Watch the movie in the link below, from the North Pole PAWS buoy, and judge for yourself.
http://www.arctic.noaa.gov/np2010/cam2-2010.mov
The Northern Cryosphere continues to lose ice at an alarming rate and will likely reach a minimum this year that is well below the 1979-2000 average. The vagarities of different Global Warming temperature analyses, although all are in very close agreement, will not alter this eventual outcome.
——-
Sorry, but looking at this movie I see nothing special about melting,
GeoFlynx
Ice loss in July has actually been the lowest in the JAXA record.
Recent 2010 Atmospheric Data near the North Pole from the North Pole Environmental Observatory
http://psc.apl.washington.edu/northpole/PAWS_atmos_recent.html
How right Pamela Gray is . Hansen is a slave and an addict in one . Climate-Exaggaration-Operator would be a proper description of his daily routine and this is exactly the way he feels , like a CEO nurturing his uncritical ego . Basically he is a civil servant with taxpayers money enabling him to gather climate-data and to publish it . He should be accountable to the taxpayers and show gratitude that he is allowed such a position in our society . It was all given to him and what did he do in return ? Fool the public ? Is the wish of superiors an excuse ? Or is he trembling because mr BO already fired some of his colleague civil servants who were straightforward and stood for the truth ?
Though I haven’t done any actual statistical analysis the PAWS buoy temp data seems to be in pretty good agreement with DMI
http://psc.apl.washington.edu/northpole/PAWS_atmos_recent.html
A constantly moving buoy doesn’t qualify as a climate reference station, but it ought to be more trustworthy than a 1200 km interpolation.