Correct understanding of storms and tropical depressions

Storms and tropical depressions (NTDs) are quite familiar words to people when unusual natural phenomena occur. However, not everyone is aware of these two natural phenomena.

What is a tropical depression?

According to science, tropical storms and low pressures (tropical depression) are called tropical cyclones (cyclone) is a whirlwind region, with a diameter of hundreds of kilometers, formed in tropical waters. In the northern hemisphere, the wind blew into the center in an anticlockwise direction.

Atmospheric pressure in the storm is much lower than around and usually below 1000mb. The difference in air pressure in the center of the storm with surrounding areas is the cause of a very high wind speed.

Storm, tropical depression can be likened to a giant cake, when cutting the cake, we see that inside it, there is also the cake of the storm and the eye of the storm.

Thus, it can be seen that the storm is a whirlwind from the blowing sides into the storm center, the closer the center is, the stronger the wind, sometimes up to several hundred kilometers an hour, but in the middle is a relatively windy area light or windy is called a storm eye. The surrounding air was centered in the middle, not in straight lines but in a spiral.

In a storm, on the floor near the surface of the four-sided air, moving in the middle, to the middle of the storm, the air moves high and then radiates all over. Typhoons originate from tropical seas, moving a huge mass of moist air. This humid air mass moves upward, the water vapor that it contains condenses into clouds and causes rain, so the storms not only have strong winds but also thick cloud cover and heavy rain.

A strong storm is approaching the land.(Illustration).

Differences between tropical depressions and tropical storms

When tropical depressions are strong enough to continuously develop enough energy to attract strong winds and steam, a tropical storm will form. Tropical storms are nouns translated from 'tropical storm' English words . The difference between tropical depression and tropical storm is distinguished by wind level.

According to the wind division of the Irish Admiral Francis Beautfort, the wind is divided into 13 levels from 0 to 12. When strong winds from level 6-7 are called tropical depressions.

Today, sometimes wind storms are described as being in the Beaufort scale from 12 to 16, which is closely related to the corresponding speed level of the Saffir-Simpson hurricane scale, in which real storms are measured. , in which level 1 of the Saffir-Simpson hurricane scale is equivalent to level 12 on the Beaufort scale. However, the extension levels in the Beaufort wind scale above level 13 did not match the Saffir-Simpson hurricane scale.

1. According to the international definition, tropical storms must have more than 64 km / h (or 35 knots) of wind , which is more than level 8. If the wind is weaker than 63 km / hour, it is called a tropical depression.
2. If it is 118 km / h (12, 64 knots), the storm is called a big storm with typhoon.
3. There is also a very strong storm or super typhoon (intense typhoon, super cyclonic storm, very intense tropical cyclone) with strong winds of more than 240 km / h (or more than 130 knots), ie level 4 in the Saffir hurricane ladder - Simpson or level 15 (Hurricane Beaufort) or more.

The noun 'typhoon' is used in the South China Sea and the Pacific Northwest; 'hurricane' in the Atlantic region; and 'tropical cyclone' in the Indian Ocean region.