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Wednesday, October 22, 2014

Another blooper by Anthony Watts, on his supposed specialty - surface temperatures

Sou | 2:24 AM Go to the first of 6 comments. Add a comment

Anthony Watts is throwing caution to the wind. He is so over that little dinner he had with scientists the other week. That's done and dusted. Today he's forgotten it even took place. He's put firmly behind him any notion of presenting science, let alone "presenting science together".

Anthony's just failed ocean chemistry, now he's failed surface temperature 101 (archived here). Anthony took a shot at Andrew Freedman for this tweet:

Anthony claims:
Gosh, “giant conspiracy”.
Um, Andrew, they all use the same base surface data. The Global Historical Climate Network (GHCN) from NOAA’s NCDC. 

Except they don't all use exactly the same data. And what data they do share, they process independently.


This is what NASA uses:
Graphs and tables are updated around the middle of every month using current data files from NOAA GHCN v3 (meteorological stations), ERSST (ocean areas), and SCAR (Antarctic stations), combined as described in our December 2010 publication (Hansen et al. 2010). These updated files incorporate reports for the previous month and also late reports and corrections for earlier months....
...The GHCNv3/SCAR data are modified to obtain station data from which our tables, graphs, and maps are constructed: The urban and peri-urban (i.e., other than rural) stations are adjusted so that their long-term trend matches that of the mean of neighboring rural stations. Urban stations without nearby rural stations are dropped. 

This is what NOAA uses - No mention of SCAR. And it's processed differently:
What datasets are used in calculating the average global temperature anomaly?
Land surface temperatures are available from the Global Historical Climate Network-Monthly (GHCN-M). Sea surface temperatures are determined using the extended reconstructed sea surface temperature (ERSST) analysis. ERSST uses the most recently available International Comprehensive Ocean-Atmosphere Data Set (ICOADS) and statistical methods that allow stable reconstruction using sparse data. The monthly analysis begins January 1854, but due to very sparse data, no global averages are computed before 1880. With more observations after 1880, the signal is stronger and more consistent over time. 

This is what JMA uses, it's different to both NASA and NOAA, though it shares the GHCN up to 2000:
JMA estimates global temperature anomalies using data combined not only over land but also over ocean areas. The land part of the combined data for the period before 2000 consists of GHCN (Global Historical Climatology Network) information provided by NCDC (the U.S.A.'s National Climatic Data Center), while that for the period after 2001 consists of CLIMAT messages archived at JMA. The oceanic part of the combined data consists of JMA's own long-term sea surface temperature analysis data, known as COBE-SST (see the articles in TCC News No.1 and this report).
Here's a description of CLIMATE messages.

And this is supposed to be one area in which Anthony Watts claims expertise. Some expert he's turned out to be!

And here's a quick chart I did, just comparing GISTemp with NOAA, adjusting GISTemp to match the twentieth century mean used by NASA for the base period - you can spot slight differences:

Data Sources: NASA and NOAA


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From the WUWT comments


It's late - so here's just a couple. You can read a few more in the archive here.

Dyrewulf
October 21, 2014 at 7:03 am
The longer it’s out there, the more Twitter becomes the litmus test for stupidity…

Oh yes, but not in the way Dyrewulf imagines.


Louis Hooffstetter
October 21, 2014 at 7:04 am
Did anyone bother to tweet the answer back to this idiot?
If not, someone needs to tweet the answer with a link to this article. (I can’t because I’m not on twitter).

Don't panic Louis, I'm about to do just that :)

6 comments:

  1. Considering the 3 agencies use different datasets etc they are in pretty good agreement on yearly timescales.

    I am somewhat unhappy about the focus on monthly records, it seems a bit silly considering the uncertainty bounds and (I suspect) effects from seasons turning early or late. But considering the constant negative propaganda barrage from the cherry-picked trendlines, what can you do?

    ReplyDelete
    Replies
    1. I forgot to add one more point: monthly sometimes gets revised, and if a record is no longer a record you can be sure it will be spotted.

      Delete
    2. It is true Harry that we have record fatigue. They are being broken all the time. E.g. the last 12 months were the hottest on record. But it is the accumulation of records that is an indication of where we are headed.

      http://thinkprogress.org/climate/2014/10/21/3581943/hottest-12-months-on-record/

      "NOAA climatologist Jessica Blunden says “It’s pretty likely” that 2014 will break the record for hottest year.”

      Delete
  2. For those who think that the difference between GHCN and JMA is small: please note that they use different datasets for the sea surface temperature and remember that the ocean is 2/3 of the Earth's surface. We world is somewhat bigger than the land stations in the USA.

    The data for GHCN and GISS is very similar, (but not the SAME). GISS does some additional processing.

    The other main global temperature datasets. CRUTEM gathers much of its own data from national weather services. BEST and ISTI have much larger datasets as GHCN. GHCN only has about 8 thousand stations, whereas the ISTI has almost 32 thousand stations.

    They all find about the same answer.

    ReplyDelete
    Replies
    1. WUWT is already telling this wrong story that all global datasets have the same stations for a longer time. You would expect that they at least get such a simple fact right. It is not science. Thus I once embarrassed myself by claiming that CRUTEM has the same stations as GHCN.

      Which tells you that you should be very careful reading WUWT. You cannot assume that any part of any post is right. No matter how simple and factual. That is also why I am very happy that I can read HotWhopper to stay up to date about WUWT and do not have to read that cesspit too often. It is a danger to your brain. Often you do not know anymore where you got a fact from and you may wrongly assume that it was from a reliable source, when it actually came from WUWT.

      Delete
    2. Victor my acoustics lecturer taught me that random noise as long as it was 15dB above a real signal would completely obscure the real signal. This is their MO. Generate as much noise as possible to obliterate the unfortunate truth. I do not know how Sou flies through these storms of nonsense and keeps her world view at a rational level. Bert

      Delete

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