Gulf Stream

Gulf Stream Origins

The origin of the Gulf Stream is debatable. One group of scientists believes that the Gulf Stream is driven both by the rotation of the Earth and by a deep-water current called the thermohaline circulation. Another group of scientists accept the theory propounded by Henry Stomme in 1948, that the Gulf Stream is a wind-driven phenomenon. Heating and cooling affect its temperature and other properties, but not its basic existence or structure. Stomme theorized that as long [Page 484]as the sun heats the Earth and the Earth spins, there will be winds, and there will be a Gulf Stream.

A NASA satellite image shows the Atlantic Ocean, off the shore of Georgia and the Carolinas, where the Gulf Stream current curves out to sea away from the North American continent.

There is some speculation that global warming could decrease or shut down thermohaline circulation, and therefore reduce the North Atlantic Drift. The time frame for this might happen is unclear; estimates range from few decades to a few hundred years. This could trigger localized cooling in the north Atlantic and lead to cooling (or lesser warming) in that region, particularly affecting areas such as the Scandinavian countries and the United Kingdom. The slowdown, which climate modelers have predicted will follow global warming, has been confirmed by the most detailed study yet of ocean flow in the Atlantic. Most alarmingly, the new research reveals that a part of the current, which is usually 60 times more powerful than the Amazon River of South America, came to a temporary halt during November 2004.

Recent research has shown that changes are occurring in the Gulf Stream. According to scientists, in the absence of the Gulf Stream and its two northern branches, the north Atlantic Drift and the Canary Current, the weather in the United Kingdom could be more like that of Siberia, which lies on the same latitude. According to Peter Wadhams of the University of Cambridge, changes are occurring in the water of the Greenland Sea. Historically, large columns of very cold, dense water in the Greenland Sea, known as chimneys, sink from the surface of the ocean to about 9,000 ft. (2,743 m.) below, to the seabed. As that water sinks, it interacts with the warm Gulf Stream current flowing from the south. However, the number of those chimneys, according to Wadhams, has decreased from about a dozen to just two. That is causing a weakening of the Gulf Stream, Wadham asserts, which could mean less heat reaching northern Europe. It is possible that the coastal areas of western Europe could be converted into deserts. However, this would require much more extensive research on changing land use patterns in coastal areas.

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