Circulating ocean waters of the past confuse Eric Worrall in the present, at WUWT

There was a new paper out in Science last week about past changes in ocean circulation. It's from a team led by  L. Gene Henry, a graduate student at Columbia University’s Lamont-Doherty Earth Observatory. What they were exploring was the past relationship between climate and ocean circulation in the North Atlantic, several thousand years ago. The paper focused on changes in the Atlantic meridional overturning circulation (AMOC).

Steve McIntyre's big blooper - mistaking water mass movement for water temperature!

Update: see below for the latest bit of continuing obstinate idiocy from Steve McIntyre, plus another diagram, plus another reference.

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There are undoubtedly a few knowledgeable people chuckling or groaning over an article Steve McIntyre wrote on his blog last week. In case you are, like me, loathe to visit a blog where the author has a tendency to both conspiracy ideation and alleging the work of scientists is a "scam" and their results "fake", these here are the nuts and bolts (as I understand it).

Steve McIntyre mistook water mass movement for temperature (archived here). Or more correctly, he mistook a measure which was used to indicate water mass movement as being used to indicate water temperature.

If you're wondering how anyone, even a climate science denier, could possibly make such a silly mistake, read on.

An AMOC early warning signal prompts panic at WUWT

There's a paper out in Nature Communications, in which PhD student Chris Boulton and colleagues say they've detected signals that can be used as an early warning of a collapse of the Atlantic Meridional  Overturning Circulation (AMOC). They used a coupled climate model that showed that these signals could become significant about 250 years before the start of any collapse, and, going by the charts in the paper, may start to be seen sooner than that.

The AMOC transports heat from the tropics northward in upper levels in the ocean in the northern hemisphere, sending cooler water southward at lower levels in the ocean. You can read more about it here at the Encyclopedia of Earth. Here's a video from YouTube: