Florida Current is weaker now than at any point in the past century | Hacker News Reader

Florida Current is weaker now than at any point in the past century

whoi.edu

71 pointshhs15 comments

There is a nice video explaining the AMOC (Atlantic Meridional Overturning Circulation) by Just Have a Think https://www.youtube.com/watch?v=6Yz8nZbZPE8

Wow, incredibly informative video. That was actually worth 10 minutes to watch!

Please read the original paper to look at the data otherwise there is not much to discuss

https://www.nature.com/articles/s41467-020-17761-w

Thanks for the link, the thing I wanted to know and this paper answered was how they measured the current and this was the cool part! They used voltage induction caused by salt water flowing past abandoned submarine telephone cables. [1]

[1]https://journals.ametsoc.org/jtech/article/31/5/1169/262

From the conclusions:

> I applied Bayesian data analysis to observations from submarine cables and tide gauges to infer the changes in the Florida Current transport at 27°N during 1909–2018.

These are important techniques for deriving a proxy for missing historical flow data. I have no confidence that the algorithms model a real-world trend but it seems to have promise as one component of a decent future model.

I did open the article/Ctrl + F for submarine cables(where did that come from?)

But was curious what can you tell from those cables? Aren't they inaccessible? Is it a strain thing or do they somehow have positioning?

I followed qserasera's link to the Nature paper. The Methods [1] section says:

> I also use Florida Current transport from submarine telephone cables at 27∘N between West Palm Beach and Grand Bahama (Figs. 1b and 2). Using electromagnetic theory, one can estimate changes in the flow from voltages induced across the cable due to the transport of charged particles by the variable current.

[1] https://www.nature.com/articles/s41467-020-17761-w#Sec8

What... wow. I was thinking maybe resistance (fiber?) or something but wow. Anyway thanks for that, very interesting.

Is this implication of this that the gulf stream will weaken and Northern Europe will cool?

I don't think there's enough information to make that conclusion. The strongest conclusion I think we can make is that ocean current's changing is almost certainly going to change regional climates in unexpected ways.

Just a theory there is not enough information

https://en.wikipedia.org/wiki/Shutdown_of_thermohaline_circu...

Not for the Snowball Earth-deniers. But for everyone else, Mexican real estate is cheap... for now.

Would be really interesting to have a qualitative description of where global ocean flows are increasing, if they are decreasing here? Or if in general, ocean circulation / transport is undergoing some change?

Or watching the video commented below, maybe it's the weakening that's happening because of the warming and freshening of arctic waters like around Greenland.

There isn't a "conservation of flow" principle for liquids, so there's no need to go looking for a flow increase somewhere else because this flow is decreasing.

My takeaway from a one year oceanography course is that ocean currents have more in common with biology than computing: they're complex, can change as the result of propagation of relatively small changes, and are inconceivable in scale.

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