Tropical storms getting stronger, say scientists

SCIENTISTS have found the clearest evidence yet that warming oceans are whipping up more powerful cyclone storms, such as Hurricane Gustav.

The strongest tropical cyclones appear to be getting stronger, a study of satellite data spanning 25 years has shown. With the exception of the South Pacific, the same pattern was seen all round the world.

The greatest changes occurred in the North Atlantic and northern Indian oceans, both of which were lashed by violent storms this year.

Hurricane Gustav, which caused the mass evacuation of New Orleans, is an example of a powerful north Atlantic cyclone.

In May the “very severe” cyclone Nargis, which developed in the Bay of Bengal, killed up to 50,000 people and left millions homeless in Burma. It was the worst natural disaster in the region since the 2004 Indian ocean tsunami.

Powerful rotating storms are known as hurricanes in the Atlantic, typhoons in the Pacific and cyclones in Asia. All come under the general heading of “tropical cyclones”.

A recent trend of increasing sea surface temperatures in the tropical Atlantic had already been linked to strengthening hurricanes in the region.

The study led by Dr James Elsner, from Florida State University in Tallahassee, US, and reported in the journal Nature, looked at maximum wind speeds in an archive of satellite data.

A significant upward trend was seen for the strongest cyclones, which was linked to rises in sea surface temperature.

The scientists wrote: “The results clearly show the strongest tropical cyclones are getting stronger.”