How strong is a storm?

Hurricane Isabel took from ISS International Space Station in 2003

Storm is a state of turbulence in the atmosphere . The storms form when a low pressure center appears the same high pressure system around it. The combination of opposing forces can create wind and lead to the formation of storm clouds.

In Vietnam, the term "storm " is often used for tropical storms, accompanied by strong winds and heavy rain. Whirlwinds range from 6 to 7 (Beaufort scale) on a large scale called tropical depressions . Vortex wind from level 8 or more on a large area, possibly accompanied by heavy rain is referred to as storm.

In addition to the Beaufort scale, there is a Saffir-Simpson scale . According to the Saffir-Simpson scale, the strongest level of the storm is 5. Livescience said the level 1 storm has a speed of 118 to 152 km / h. A storm level 5 moves at a speed of 250 km / h or more. Many scientists believe that, if level 6 is born, storms in that level will have speeds of 280 to 314 km / h.

The storm strengthened by warm waters in the ocean. In the context of global warming, ocean surface temperatures also increase. Therefore, scientists predict that the storms are also stronger.

But physicists insist that the power of a storm cannot rise to infinity. Based on the conditions of the atmosphere and oceans today, Kerry Emanuel - a meteorologist at the Massachusetts Institute of Technology in the US, thinks the maximum speed of a storm is 304 km / h.

However, the upper limit of the speed of the storm is not an absolute number. It may change according to climate fluctuations. The scientific world predicts that as the global warming continues, the maximum intensity of the storm will increase in the future.

The satellite image of NASA shows the devastating devastation of super typhoon Haiyan as it moves deeper into the Philippines.

Emanuel and some meteorologists stated that, if the ocean surface temperature increases by a degree C, the storm speed will increase by 5%.

But Chris Landsea, an expert at the US National Hurricane Center, disagrees with this prediction. Landsea said that even if the ocean surface temperature increased by 6 degrees Celsius in this century, the wind speed would only increase by 5%. That means the speed of the storm cannot exceed 320 km / h.

However, according to the World Meteorological Organization, in 1961 super typhoon Nancy in the northwest Pacific region reached a maximum speed of 344 km / h.

On April 12, 1934, a storm swept across Mount Washington, New Hampshire, USA at a speed of 370 km / h. But that is not yet the highest intensity of the storm. In a tornado in Oklahoma, USA, scientists measured wind speeds of 509 km / h.