For most people , slowing or even stopping the Gulf Stream could only be a sci-fi story.This vast oceanic current on the surface of the Atlantic , wich runs from the intertropical zone towards the shores of Europe (thus ensuring our mild winters and temperate summer) cannot simply "break down".
However , a reduction in its intensity , or even its coming to a complete halt , is not impossible.The climatic history of our planet shows this.The Gulf Stream has already seen some major disturbances to its "flow".Canadian , American and British researchers , whose work was partly funded by the European Union's 5th Framework Research Programme , reckon that over the past ten years , the global warming of our planet has modified the salinity of ots oceans , wich in turn may disturb the circulation of marine currents ( know as thermohaline circulation).
If the Gulf Stream malfunctions , then Europe , deprived of ots effects , will in turn lurch towards a new era of lower temperatures. In other word , winters in Lisabon may become as rigurous as those in New York. Fact or fiction ? The climatic history of our planet shows that such a development in the past - a considerable influx of fresh water in the North Atlantic resulting from a massive offloading of ice from the American ice sheet - has already seen the Gulf Stream mechanism put "out of order".A question of salinity It is the increased evaporation of surface water in temperate regions , generating a significant surplus of water vapour in the atmosphere and more precipitation of fresh water at higher latitudes , that could be briging about such a change in the salinity of the North Atlantic.
Water with a lower salt concentration does not drop easily to the ocean depths , wich is what usually happens to the Gulf Stream to the north of Iceland. It is here that this famous current plunges to the ocean floor before returning to the tropics and then , further south , towards the Antartic Ocean .In other word , this deep ocean current is the "return" of yhe surface Gulf Stream. After more intense rainfall , however , the additional fresh water in the mix inhibits the Gulf Stream's drop towards the ocean floor, and jams up this vast , worldwide climatic mechanism.This in turn interferes with , or even blocks off , the Gulf Stream on the surface.
Source: RDTinfo Magazine on European Research.
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