[ROCKMAN]

"...to the understanding of average individuals.". Average individual which means half the population isn't that smart. LOL.

[dolanbaker]

update A curious cold spot in the Atlantic has scientists thinking their worst fears have come true
http://inhabitat.com/a-curious-cold-spo ... come-true/

Well we did experience colder than average spring temperatures here, but I'm only talking a couple of degrees (C) or so, after an exceptionally wet winter.

More recently, we've had "an Irish Heatwave", maximum temperatures exceeding 25 degrees for more than three days, it's back to normal now (showers & 16C with light westerly winds).

These sort of variations really are in the noise as far as climate change in concerned.

[vtsnowedin]

If the Gulf stream is slowing down would there not be less warm water showing up between Norway and Svalbard island and less ice being melted by it?
It seems in the Arctic ice thread they are at record lows for the date so something doesn't add up.

[dolanbaker]

From what I can gather, it's not "cold" water that is sitting in the Atlantic, just water that is not as warm as in previous years, it is still warm enough to melt the ice off the Norwegian coast as usual.

[AdamB]

https://robertscribbler.wordpress.com/2015/03/23/world-ocean-heartbeat-fading-nasty-signs-north-atlantic-thermohaline-circulation-is-weakening/#comment-37034

http://www.realclimate.org/index.php/ar ... -atlantic/

https://www.youtube.com/watch?v=L-bXLPLCyek#t=11

http://forum.arctic-sea-ice.net/index.p ... 199.0.html

This is big, folks.

So...like more than a year later...anyone noticed...anything...yet? What does it take to be "big" nowadays?

[dohboi]

AB, we're talking about climate here. Usually, notable climate trends take about 30 years (or more) to even be able to clearly identify and at least that to consistently feel the effects of. The actual world, you know, is not a Hollywood movie.

There's still a big blob of anomalously cool water in the NW Atlantic last I looked, so the dynamics are still in play and likely getting stronger. We don't know exactly what all the effects will be. It has already caused periods where the British Isles and parts of Western Europe got pummeled over and over again by major storms riding along the differential between the cold blob and the warmer parts of the ocean further south. The slowdown seems to be increasing rates of sea level rise in Florida and other parts of the East Coast, iirc.

But I haven't kept up on all the latest science around this. Was there something in particular you were wondering about or wanted to contribute?

[vtsnowedin]

From what I can gather, it's not "cold" water that is sitting in the Atlantic, just water that is not as warm as in previous years, it is still warm enough to melt the ice off the Norwegian coast as usual.

Sounds like a distinction without a difference to me.

[dohboi]

?

Not sure what point you're trying to make, but then I'm coming down with a cold and am a bit fuzzy today, and so maybe I'm missing something obvious.

Meanwhile...looking further into it, it turns out that there is, in fact, a recent study that purports to show that earlier concerns were perhaps premature and that the enormous melt from GIS can not reliably be shown to have measurably slowed down the AMOC...yet.

https://www.washingtonpost.com/news/ene ... rculation/

Last year, a bombshell scientific study suggested a scenario that has long worried scientists was coming to pass: a slowdown in the North Atlantic ocean currents that usually redistribute warm and cold waters, thanks to massive ice melts in Greenland and other Arctic changes.

If this is really happening, it’s a big deal.

The circulation, sometimes called the Atlantic meridional overturning circulation or AMOC, transports enormous amounts of warmth northward from lower latitudes. If it slows down, there will be less heat transport to Europe and higher latitudes, as well as key consequences for warming and sea level rise along the U.S. east coast.

However, this is a vast, enormously complicated and inadequately studied ocean system, and there are well-known patterns of natural variability in the Atlantic that could also drive things.

Indeed, the circulation had already been observed to be slowing over the past decade, but it is less clear whether this slowdown is the result of climate change or, simply, part of that variability (or both).

[vtsnowedin]

?

Not sure what point you're trying to make, ....
....

Just pointing out the contradiction between record rates of arctic sea ice melt and having the gulf stream slow down and or having a cold area in the North Atlantic. If both are true simultaneously there has to be some rather complicated explanation for it.
The ocean currents are complicated by the position of the continents, the rotation of the earth, the tidal force of the moon and the angle and intensity of the sun.
But to look at it at it's simplest it is a thermosyphon loop that is driven by the temperature differential between the equator and the poles. Sunlight hitting equatorial water warms it and it expands out away from the equator and travels on the surface both north and south towards the poles. Upon reaching the polar regions the heat that was absorbed in the tropics is given up and radiated out into space and the water contracts becoming denser and sinks and heads back toward the tropics at a lower level completing the loop.
So what happens if the temperature differential changes? Less heat radiates out into the arctic night because it is held in by green house gasses.
So if before the equator year round average temp was +35 C and at the pole it was -20C there was a differential of 55C driving the loop. So now perhaps we have still +35 at the equator and -10C at the poles. for a difference of 45C. That is going to drive the loop at a slower rate but would certainly not stop it. On the other hand if the temperature at the equator rose as well then the differential would stay the same and there should be no change in the speed and volume of the current.
That is my simplified explanation of how it works and I don't see anyway it will stop as long as the sun continues to shine.

[dohboi]

I don't think the major focus is on temperature differentials between the North Pole and the equator for AMOC shut down (or even much slowdown).

What more immediately is making people concerned is the change in salinity with lots of fresh water coming into the current from increasingly huge melt from the Greenland Ice Sheet.

It's the increase in salinity as the warm water continues north that is the main driver of the current sinking at some point in the north. If you think about it, the water isn't likely to become colder than the water that is already up there, so temperature differentiation is not likely to be a major player in AMOC circulation, at least not in the direct way you seem to be implying. But perhaps I'm missing something?

[ennui2]

What you're missing is that VT is not a climate scientist and should not cast skepticism on a theory based on an incomplete grasp of the topic. As the years progress, VT has been kind of dragged from his initial denialist position (where he came across as denialist but wanting to shy away from self-describing as a denialist) over to what sounds like a downplaying position. That's the way he's gonna be, always trialing behind the current party-line on where we're headed.

[vtsnowedin]

What you're missing is that VT is not a climate scientist and should not cast skepticism on a theory based on an incomplete grasp of the topic. As the years progress, VT has been kind of dragged from his initial denialist position (where he came across as denialist but wanting to shy away from self-describing as a denialist) over to what sounds like a downplaying position. That's the way he's gonna be, always trialing behind the current party-line on where we're headed.

I suspect I'm just as much of a climate scientist as you are Ennui2.
Go back to the question I posed up thread and put forward a plausible explanation.

Just pointing out the contradiction between record rates of arctic sea ice melt and having the gulf stream slow down and or having a cold area in the North Atlantic. If both are true simultaneously there has to be some rather complicated explanation for it.

[dohboi]

" If both are true simultaneously there has to be some rather complicated explanation for it."

???

The explanation is rather straightforward, actually.

Perhaps you could be clearer about what you find 'contradictory'?

[vtsnowedin]

" If both are true simultaneously there has to be some rather complicated explanation for it."

???

The explanation is rather straightforward, actually.

Perhaps you could be clearer about what you find 'contradictory'?

If you don't understand my question how can you be sure the answer is straightforward?

[dohboi]

Your question is incoherent. Melt of ice IS going to be the major cause of any AMOC slowdown that happens, mostly because it will freshen the surface water, but also cool it.

Yet for some reason you seem to think that melting ice is some kind of proof that the AMOC can't slow.

But if you don't want to talk about it, that's fine.

[vtsnowedin]

Your question is incoherent. Melt of ice IS going to be the major cause of any AMOC slowdown that happens, mostly because it will freshen the surface water, but also cool it.

Yet for some reason you seem to think that melting ice is some kind of proof that the AMOC can't slow.

But if you don't want to talk about it, that's fine.

The surface "water" is ice. Melted ice is warmer then it was before it melted so melted ice will make the surface warmer then it was. Right?

[AdamB]

AB, we're talking about climate here. Usually, notable climate trends take about 30 years (or more) to even be able to clearly identify and at least that to consistently feel the effects of. The actual world, you know, is not a Hollywood movie.

Read the title to the thread. Note that it doesn't say "Gulf Stream Shut Down happening now, effects to be seen by your grandchildren. Maybe. But its big!"

I am simply asking that an effect, claimed to be happening NOW, when NOW was more than a year ago, really need to be labelled big when indeed, it was not? The question might be, "Is fear mongering really required?".

I realize this is a peak oil site, and once that was redefined to be glut and low prices, something else cool and scary might have been necessary to keep up morale among those looking for the trigger to their next apocalypse dreams. Lets face it, right now there are legions of barrier island real estate owners along the eastern seaboard horrified that their great grand children might have to sell the property before rising seas wash it away in a century or so, but I'm betting that even they, with skin and money in the game, aren't thinking of it as a "big" thing quite yet.

Whereas THIS thing...happened more than a year ago. The Gulf Stream shut down. Amazing. And England has not been returned to climate more similar to what its latitude otherwise would imply?

[AdamB]

"...to the understanding of average individuals.". Average individual which means half the population isn't that smart. LOL.

Find me an average individual. I dare you. The average human has one testicle and one breast. I've never met one.

[vtsnowedin]

Find me an average individual. I dare you. The average human has one testicle and one breast. I've never met one.

I'm quite sure I wouldn't want to.

[dohboi]

"something else cool and scary might have been necessary to keep up morale"

Ah, I see you're an idiot. Thanks for letting me know so I can put you on my ignore list.