Saturday, November 7, 2015

Temperature records broken in TempLS October

I've been following some very large spikes in the NCEP/NCAR index during October, with an eventual rise of about 0.2°C. Then followed big rises in the satellite indices, with UAH up about 0.18°C and RSS up 0.07. Here is the first surface index. TempLS mesh (report here) rose by 0.21°C, and TempLS grid by 0.03°C. There is rather a contrast here, which I'll say more about. However, TempLS grid had drifted well ahead of mesh, so this represents a degree of catch up. The result is that both are the hottest month (of all months) in their respective records, by quite a long way (plots below).

The reason for disparity seems to involve SST, and maybe sea ice. TempLS grid uses lat/lon grid cells, and has several without data. In this respect is resembles HADCRUT and NOAA, and often follows them closely. TempLS mesh has a full triangular mesh, so interpolates everywhere, more like GISS. In October, you can see a breakdown of the contributions to TempLS Mesh in the report (scroll down). A main feature is the reversal of Antarctica from cold to warm. The grid methods underweight this.

A paradox is that most indications are that SST did not rise. HADSST shows a small decrease. TempLS mesh shows an increased contribution from SST.

You can see the regional patterns in the report, and in more detail here. Antaarctica and Australia were big hotspots. Brazil is still missing. The heat in Australia is noted here.

So what does this all mean? I think there will be substantial rises in the main indices, setting more records for hottest anomaly. The rises probably won't be as high as the reanalysis, since SST will be a larger damping component. Below the fold, I'll show plots of the last 20 years of TempLS monthly, and a WebGL global plot of the differences going from September to October. Again Antarctica and Australia are the big factors.

Here is TempLS mesh



October stands out, though in TempLS there was also a big spike in 1998 - more so than in other indices. Here is TempLS grid:



Obviously the rise from September is less, but it followed a larger earlier build up. Now here is the WebGL gadget. It shows, in color shading, the changes going from September to October. Again Antarctica and Australia stand out, with seemingly no change in SST. SST changes are small and fairly even, so they tend not to show on the scale of the more volatile land. Europe cooled, central Asia warmed. As usual, the global is a trackball - right mouse button to zoom.






16 comments:

  1. Nick, re: layout :: in Safari , but not Firefox or Chrome, the globe overlays the graphs.

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    1. Thanks, David - I don't routinely check Safari. I'll see if putting it in an iframe helps.

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  2. Looks good in my Safari.

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  3. Temperatures are rising again ! After that incredible october, GFS forecast for 12 nov 2015 are even more impressive. Let's see your NCEP data in the next days

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    1. I'll watch for that. This time, Australia isn't pulling its weight, at least not here.

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    2. Ok, let's test the GFS forecast. My qualified guess is that NCEP/NCAR will peak at 0.78 C Nov 12, and the month-to-date temp Nov 18 will be 0.55 C..

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    3. For nov 19, I saw a month to date of 0,52°C (base 1981-2010, so a different one) for GFS. and peak of 0,82°C (81-10) on nov 12. If the month to date goes the same way all november, it will be a little behind october.

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    4. KC, it look's like we are using the same source: http://www.karstenhaustein.com/climate
      but I do some recalculation/adjustment of data to fit Nick's NCEP/NCAR. It is possible that the peak will come Nov 13 if Nick uses Australian time and not UTC

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    5. Olof,
      The NCEP/NCAR data comes as labelled days - I assume UTC. That's what I use.

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    6. Yes, Olof, it is the same source, karstenhaustein.

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    7. Good morning, Nick,
      I think that TempLS can get a real kick from Brazil, which shows quite high Oct anomalies (+2-4 C) in Ogimet. Northern Greenland was also that warm (at DMI) so we can expect large areas of Brazil and the Arctic to turn red on the map, and push TempLSmesh above 0.9 C

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    8. Olof,
      Thanks, we'll know tomorrow. On the interpolated map (as of today) Brazil shows as quite cool, so that will make a change.

      Temperatures in TempLS Oct have been creeping up anyway. Only 0.005 in mesh, but 0.02 in grid. That reduces the discrepancy a little.

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    9. Given the TempLS data for Oct, GISS could be really 1.00.

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    10. Anon, 1.00 C is a conservative estimate. The preliminary TempLSmesh for Oct is 0.13 higher than the previous monthly record anomaly in Jan 2007.
      If GISS rises 0.13 from its Jan 2007 record, October will be 1.10 C.
      Maybe 1.05, in the middle of those bounds, is a reasonable guess..

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  4. Olof, I did a multi-linear regression of the existing Oct 2015 data sets and get depending on the number of parameters and if I try to fit the residual annual cycle values between 0.95 and 1.04. The weighted mean if the models was 1.00.

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