Mysterious Jump in Ocean Temperatures

Back in 2018 Jo Nova publicised Dr John McLean’s exposé of the many ridiculous flaws in HadCruT4, the global temperature dataset, which included until a year ago the oceanic component, HadSST3. That was bad enough, with some data from positions 100km inland from the nearest sea. But in June 2019 the long awaited HadSST4 was released, in which many corrections were made to reduce “problems” in the sea surface temperature record.

Corrections indeed.

Figure 1 is a comparison of HadSST4 with HadSST3.

Figure 1: HadSST3 and HadSST4 since 1850

And figure 2 shows the extent of the “corrections”.

Figure 2: Adjustments: HadSST4 minus HadSST3

You will no doubt note how the “corrections” have made the past cooler, as is standard practice for all those curating temperature records. Indeed, apart from a small foray in the 1940s, the whole 100 years from 1875 to about 1975 has been made ever so slightly- up to a tenth of a degree- cooler.

But in an interesting move, all temperatures since then have been corrected, and, would you believe, upwards. Who would have thought that the average sea surface temperature measured just a couple of years ago in September 2017 was 0.1875 degrees too cool, and needed revising upwards?

Figure 3: HadSST3 and HadSST4 since 2010

Modern thermometers just aren’t what they used to be.

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3 Responses to “Mysterious Jump in Ocean Temperatures”

  1. Peter Newland Says:

    Some syndicated Melbourne suburban newspapers often publish graphs that encourage people to take action re climate change. Their graphs include: reduced “rain-DAYS/year” trends implying water shortages; and, increasing temperature trends over the last 50 years for suburbs that have grown rapidly in that time. But how/where can I do fact-checking to find the actual rainfall-MILLIMETRES/year and the temperature records for a nearby area where the land use has not changed dramatically in the past 50 years. Hopefully you can point me in the right direction.

    • kenskingdom Says:

      Hi Peter. Go to . At 1., use the drop down box to select rainfall. (You can get temperature here as well). Then select whether you want daily or monthly/ annual data. At 2., type in a town name e.g. melbourne. Click find, then select any one of them. Under that, click on a station you might like, then at 3., click on Get Data. You will then go a page of the current year, but you can select any year. I’d go the top right part and click on “All years of data”. This downloads a file which you can unzip and open, showing you all past data. You would be better off typing in towns a bit out of Melbourne e.g Geelong will give you a much wider list. I don’t know the area but you get the idea. Good luck.

  2. Peter Newland Says:

    Thanks Ken. Much appreciated.

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