Tuesday, September 19, 2017

GISS August up 0.01°C from July.

GISS showed a very small rise, going from 0.84°C in July to 0.85°C in August (GISS report here). TempLS mesh showed a very slight fall, which I posted at 0.013°C, although with further data is is now almost no change at all. I see that GISS is now using ERSST V5, as TempLS does.

The overall pattern was similar to that in TempLS. Warm almost everywhere, with a big band across mid-latitude Eurasia and N Africa. Cool in Eastern US and high Arctic, which may be responsible for the slowdown in ice melting..

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

Here is GISS


And here is the TempLS spherical harmonics plot



This post is part of a series that has now run for six years. 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.









8 comments:

  1. 0.85 C, Nick, not 0.65 C.

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  2. I was very surprised as TempLS mesh Aug cooled, because I expected an large rise of GISS Aug to about 0.93 because of a similar rise of GFS temp (even higher than Aug 2016!) on karstenhaustein.com
    Strong difference of GFS and NCEP this time.

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    1. GFS has upgraded to a newer model version. Don't know whether this affects the bias correction that I'm applying to match GISS. So far things seem unchanged, assuming that the positive NH-September bias (which I didn't see in the years before) is mainly down to the crazy US wildfire situation which naturally biases weather models warm. We will know better in a month or two ...

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    2. Looks like September could be warmer than August. Maybe GISS will catch up?

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  3. So it seems to me that as long as the globe averages better than 0.75 for the rest of the year (which seems more likely than not: the last 3 months averaged .79), that 2017 will rank 2nd warmest in the GISS temperature record. -MMM

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    Replies
    1. "...better than..."? The warmer, the better? I try to combat AGW.

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    2. Hah, good point. As a scientist, I should be more precise with my language and not fall into "horse race" terminology...

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