While Odisha braces to face a major cyclone, we give you all the info on typhoons. Haima typhoon had forced the evacuations of 50,000 people in southern China after hammering northern Philippines with ferocious wind and rain, triggering flooding, landslides and killing at least 13 people
Tropical cyclones, better known as hurricanes in the US and typhoons in the Far East, are massively destructive weather events that at lower latitudes, begin as weaker, low-pressure weather systems. Tropical cyclones form over very warm seas, typically in late summer and autumn in each hemisphere. As they intensify they become driven by latent energy release from water vapour, which condenses to form the high storm clouds. Wind speeds of over 200 km hr have been recorded around the centre of a storm, but devastation is mainly caused by flooding as a result of the surge in sea surface height and the intense rainfall. The 1970 Bhola cyclone was one of the worst natural disasters of all time, killing half a million people in Bangladesh and West Bengal largely as a result of such flooding, but it was far from the most powerful tropical cyclone, rating a relatively moderate Category 3. The strongest, category 5, storms include Hurricane Katrina in 2005 with winds of over 280 km hr-1.
What is a Category 5 storm?
This storm occurs when hurricane has reached the most powerful classification of storms on the Saffir-Simpson hurricane intensity scale (scale to measure hurricanes), category 5. The scale measures wind speed, while storm surge can cause tremendous damage as well. A category 5 storm has winds stronger than 155 miles per hour. Such strong winds are associated with catastrophic damage: homes destroyed, trees and power lines felled, and other devastation. After a category 5, expect the power to be out for weeks, even months; a place that such a storm has blown through is not likely to recover soon. Some scientists have suggested that powerful storms like Patricia (second-most intense tropical cyclone which hit US in 2015) are showing the limitations of having just five categories, and that the scale should be expanded.
How and why tropical storms are named?
The first use of a proper name for a tropical cyclone was by an Australian forecaster early in the 20th century. While the Southwest Indian Ocean tropical cyclones were first named during the 1960/1961 season, the North Indian Ocean region tropical cyclones (which includes the Bay of Bengal and Arabian Sea cyclones) are being named since October 2004, added Sen. The months of May-June and October-November are known to produce cyclones and storms of severe intensity. Hurricanes developing during the monsoon months (July to September) are generally not so intense, added the met director. Prior to 2004, cyclones in the north Indian Ocean were nameless. In 2004, an international panel on tropical cyclones led by the World Meteorological Organisation decided to name the cyclones. Eight countries - India, Pakistan, Bangladesh, Maldives, Myanmar, Oman, Sri Lanka and Thailand attended the meet. They came up with a list of 64 names from each country for upcoming cyclones. Names can be suggested by the general public in the member country or by the government. India, for example, welcomes suggestions on the condition that the name must be short and easy-to-understand, not culturally sensitive, and not convey some unintended and potentially inflammatory meaning.
Global warming is causing more typhoons
Scientists have found support for the controversial idea that global warming is causing more frequent and destructive hurricanes, a subject that has been hotly debated during the past decade. Data gathered from tide gauges, which monitor the rapid changes to sea levels caused by storm surges, show a significant link between both the frequency and intensity of tropical storms and increases in annual temperatures since the tidal records began in 1923. The study found that during the 90-year period, when the average global temperature has increased by 0.7C, extreme hurricanes similar to Katrina, which devastated New Orleans in 2005, were nearly twice as likely in warmer years as colder years. Although scientists were not able to prove that climate change is causing more large hurricanes, they believe the study is consistent with the predictions that global warming and warmer seas could bring about more intense tropical storms. Hurricanes form when the sea’s surface temperature increases above 26C. However, they result from a chaotic interaction between the difference in sea and air temperatures, humidity and wind.
What is the difference between cyclone, hurricane, tornado and twister?
nA cyclone is any kind of circular wind storm. But now, it is only used to describe a strong tropical storm found off of the coast of India. Hurricanes and typhoons are the same thing, but in different places. On the coast of Florida, it is called hurricane. In the Philipines, it is called typhoon. Hurricanes occur in the Atlantic and typhoons, in the Pacific. Basically, hurricanes and typhoons form over water and are huge, while tornados form over land and are much smaller in size. A tornado is a violent windstorm characterised by a twisting, funnel-shaped cloud.
What they can do?
High winds typhoons have sustained winds greater than 70 miles per hour. Super typhoons aren’t officially on Japan’s scale, but colloquially are known to have 120 mile-per-hour sustained winds – similar to a category 4 or 5 hurricane.