In discussions about climate change, concern is expressed about the stability of the Gulf Stream. this current is important to the climate of Europe, because it sends warm water flowing into the North Atlantic-if it ever ceased flowing, the climate of England and Western Europe would become drastically colder. Is these such a current in the South Atlantic? Does is play a big role in the climate of South America?
The Gulf Stream is part of a set of currents called the North Atlantic Gyre (the other parts of it being the North Equatorial Current, the North Atlantic Current, and the Canary Current). This gyre circulates water generally clockwise around the North Atlantic.
There is also the South Atlantic Gyre, the North Pacific Gyre, the South Pacific Gyre, and the Indian Ocean Gyre.
The Brazil Current (part of the South Atlantic Gyre) is the southern equivalent of the Gulf Stream. It is much weaker than the Gulf stream though and doesn’t have as much of an effect on climate.
All of these currents do affect climate and ecology, though.
The wikipedia articles are a bit sparse, but they make a good starting point:
There are links to pages for the individual gyres there.
The role of the Gulf Stream in Europe’s climate is overinflated, as explained here:
A good example is the cold outbreaks in Europe in recent winters, which were caused by a reversal of the normal atmospheric circulation. Also, consider how mild the Pacific Northwest is compared to New England, for the same reasons.
I read or heard this story somewhere:
Once upon a time, North America was mostly covered by a huge glacier. There was a puddle of melted water on top of the glacier, forming a massive lake. One year, a portion of the glacier, forming the “shore” of the lake towards the east (Atlantic) coast broke away, and some massive amount of chilled water flowed out of the lake into the Atlantic.
This disrupted the Gulf Stream, and within another year to two, Europe fell into an Ice Age because of it.
(I’m having a somewhat vague recollection that I heard this story from Al Gore, in his movie “An Inconvenient Truth”.)
Many people confuse the Gulf Stream with the thermohaline circulation, which is what would make (mainly northern) Europe colder, as dramatically shown here (including a map, note that the pattern of cooling, over the entire North Atlantic, is nothing like what you might expect from a collapsed Gulf Stream, which should only cause cooling in its path). Of course, one has to again look at climates like the Pacific Northwest, where there is no such warming effect (if anything, it appears that the cold part of the THC (see link) rises in the North Pacific, cooling it down), yet they aren’t that cold compared to places like Atlantic Canada.
“The gyres! the gyres! Old Rocky Face, look forth;
Things thought too long can be no longer thought,
For beauty dies of beauty, worth of worth,
And ancient lineaments are blotted out.
Irrational streams of blood are staining earth;
Empedocles has thrown all things about;
Hector is dead and there’s a light in Troy;
We that look on but laugh in tragic joy.”
James Burke’s “After the Warming” 1989?
Lake Agassiz a vast meltwater lake in central Canada which began flowing into the Atlantic through the St. Lawrence River
The effect is due to the change in salinity in the Gulf Stream, not temperature
Although I know what you’re saying is true, it sounds hysterically like a Bond villain’s plot:
“You are too late, Mr. Bond! The machine has already reversed the normal atmospheric circulation over Europe, plunging the continent into an icy grip – mine!”