Saturday, October 15, 2022

GISS September global temperature down by 0.06°C from August.

The GISS V4 land/ocean temperature anomaly was 0.88°C in September 2022, down from 0.94°C in August. This drop is very similar to the 0.061°C fall reported for TempLS.

As usual here, I will compare the GISS and earlier TempLS plots below the jump.

Here is GISS V4

And here is the TempLS V4 FEM-based plot

This post is part of a series that has now run for seven years. The GISS data completes the month cycle, and is compared with the TempLS result and map. GISS lists its reports here, and I post the monthly averages here.
The TempLS mesh data is reported here, and the recent history of monthly readings is here. Unadjusted GHCN is normally used, but if you click the TempLS button there, it will show data with adjusted, and also with different integration methods. There is an interactive graph using 1981-2010 base period here which you can use to show different periods, or compare with other indices. There is a general guide to TempLS here.

The reporting cycle starts with a report of the daily reanalysis index on about the 4th of the month. The next post is this, the TempLS report, usually about the 8th. Then when the GISS result comes out, usually about the 15th, I discuss it and compare with TempLS. The TempLS graph uses a spherical harmonics to the TempLS mesh residuals; the residuals are displayed more directly using a triangular grid in a better resolved WebGL plot here.

A list of earlier monthly reports of each series in date order is here:

  1. NCEP/NCAR Reanalysis report
  2. TempLS report
  3. GISS report and comparison with TempLS


  1. I notice the TempLS plot indicates a slightly weaker warm anomaly in the Arctic and a slightly cooler anomaly over much of Australia. With sparse data in the Arctic, who knows which is better, but there is plenty of data in Australia - so that's a bit puzzling.

    I haven't commented here in a while, so I'm hoping you and family are doing well in these increasingly trying times. I just recently hit 70 and can't complain too much at present - just wish so many economies weren't looking so gloomy.

    1. Good to hear from you, Bryan,
      Yes, we're a good deal past your milestone, but still soldiering on. And keeping up the temperature calcs keeps the mind active.

      Yes, there is a notable difference in Australia. GISS is using adjusted data, I use unadjusted. It doesn't usually make a difference with current data, but6 may have an effect here.

      I agree that sparseness in the Arctic makes it hard to work out which is right. I think the GISS grid may give trouble there - there are actually bits missing in the Antarctic.

    2. Yes, keeping the mind active is a good thing as we get older.

      Just for grins, I went and looked at the EU Copernicus ERA5 analysis for September 2022 and to me it looks closer to TempLS for both the Arctic and Australia, as near as I can tell with the different color scales.

    3. Hi Bryan
      I made a map using adjusted data. It matched the unadjusted in Australia and Arctic, so that isn't the explanation.

    4. Interesting. As usual, more questions than answers.

  2. Hi Nick, Off topic, but germane to the discussion on IPCC projections happening at WUWT. You might want to remind his Lordship of these words, from 2015

    "I had not recalled that IPCC had made its 1 k by 2025 prediction under Scenario A. However, Scenario A was its business-as-usual scenario, and it had incorrectly predicted a far greater rate of forcing, and hence of temperature change, than actually occurred."

    1. Thanks, Phil
      Yes, that is a good reminder. However, I'm currently having trouble getting him to acknowledge the very explicit FAR emissions plot, and the thread is running out of steam.

    2. Wow. Monckton's ability to totally ignore what he doesn't want to admit is truly impressive!

    3. Apparently you were too convincing for him to attempt to respond again by citing the "verbatim" quote in the "head posting", so he just stopped engaging entirely.

      Monckton: "Mr Stokes wriggles in vain. IPCC plainly predicted that on Scenario A CO2 emissions would increase by 10-20% compared with 1990 by 2020. The text is given, in full, in the head posting. No ifs, no buts."

      Everyone else: But... the IPCC never used the word 1990 in that sentence! All the buts, and all the ifs!

    4. Ah, I see that he created an entirely new post, with new and different confusions about what the IPCC said. Monckton Gallop!

    5. Yes, this stuff is funny. In the previous thread, scenario A tonnage emissions of CO2 were said to be 3-4 times lower than what happened. That if true would be serious, since A was the high emissions scenario. Now the claim is that the radiative forcing increase was higher, about twice what happened. But the logical conclusion of that is that a lower emissions scenario is what actually happened, and the forcing looks like B. We'll see how that develops.

    6. Monckton's amazingly graceless concession: "I had been misled by poor drafting on IPCC’s part. Buried in the body of the report was a paragraph making it clear that IPCC had not meant what it had said in its official definition of Scenario A."

      There is potentially an interesting question in his follow-up post: how did the IPCC do in terms of getting the carbon cycle right? However, since he compares CO2 emissions vs. total forcing from all GHGs, it is impossible to tell what's going on. And I'm not going to do the work for him of digging into the FAR to figure out.