Slashdot Mirror
Rare South Atlantic Hurricane Heads Toward Brazil
jellisky writes "An unprecendented sort of weather event has been occuring recently, without much fanfare at all. A tropical cyclone in the south Atlantic is slowly drifting toward Brazil. The southern Atlantic ocean isn't exactly a hurricane hotbed, as pointed out by National Hurricane Center forecaster Jack Beven, "We know there hasn't been a hurricane in that area since at least the satellite era, the mid-60s at the minimum." The storm is a small one, though, but has estimated winds near minimal hurricane strength (74-95 mph). It's quite an interesting sight, perfect for piquing the weather curiousity that many of us have."
Oh, but I think that's what makes them so interesting though... The more we know about these storms (their patterns, forces behind them, etc.), the more we can do to be better prepared for them -- potentially saving people's lives that would otherwise be lost.
huzzah
Global warming is just that - a warming, on average, of the globe.
The fact that the majority of the South Atlantic is cooler than average could reflect any one of a number of causes, one of the most likely of which is a warming of the Antarctic leading to increased melting of the icecap, thus releasing lots of cold water into the South Atlantic.
Looking at the chart, this seems plausible, as the concentration of colder water is away from the continental shelf of South America, and appears to skirt around the South Atlantic islands (notice the finger of yellow / orange sticking out from the coast of Argentina).
Cyclone formation is driven by temperature gradients, rather than average temperature, and the fact that the (normally slightly warmer) water on the continental shelf is warmer than usual, whereas the deepwater areas are colder, leads to the conclusion that the temperature gradient is much higher than usual.
So it's not surprising that a cyclone has formed, and the anomalous temperature gradients are perfectly consistent with global warming.
One thing from the map - I'd love to be in a boat off Namibia right now, watching the dolphins and whales - that extra cold water will be full of food, and it'll be a bumper autumn's fishing all along the South-West coast of Africa.
oh brave new world, that has such people in it!
Not to say that you are wrong and this does have anything to do with global warming, just that I think only looking at water temperature is not enough to be conclusive.