Cyclones and hurricanes may sound like different kinds of natural disasters, but these tropical systems are actually quite similar. The two storms fall under the overarching category of “tropical cyclone,” which is “a rapid rotating storm originating over tropical oceans from where it draws the energy to develop,” according to the World Meteorological Organization (WMO).
The biggest difference is the terminology we used to distinguish them depending on their geographic locations:
- A tropical cyclone that reaches speeds of at least 74 miles per hour (119 kilometers per hour) and takes place in the Caribbean, the Gulf of Mexico, the North Atlantic Ocean and the central North Pacific Ocean is referred to as a hurricane.
- Those that occur in the Northern Indian Ocean (the Bay of Bengal and Arabian Sea) are called tropical cyclones.
- In the western South Pacific and southeast Indian Ocean, these storms are known as severe tropical cyclones.
- In the North Pacific the correct term is typhoon.
So why the different names? Well for one, hurricanes, cyclones and typhoons originate in specific locales on the globe and they form during different seasons. The tropical cyclone season in the Northern Indian Ocean, which includes the Bay of Bengal and Arabian Sea, has two peaks of activity. The first occurs from April until June and the second is from September until December. The strongest cyclones occur during the fall peak.
The Atlantic hurricane season, on the other hand, runs from June 1 to Nov. 30. But the most powerful and most destructive hurricanes usually occur in August, September and early October for several reasons: This is when African easterly waves are most developed; wind shear that can destroy potential tropical cyclones tends to be low; sea-surface temperatures are at their peak; and atmosphere instability also rises in the fall.
In the North Pacific, typhoons typically form from May through October, although they can generate all year.
The worst place for these storms is in the Bay of Bengal, where 26 of the world’s 35 deadliest tropical cyclones have been recorded. In May 2020, Super Cyclone Amphan made landfall in eastern India as the strongest storm ever recorded in the Bay of Bengal.
What makes it so deadly? Well the Bay of Bengal is the world’s largest bay, and it’s bordered by India, Bangladesh, Myanmar and Indonesia. It’s highly cyclone-prone because its shallow and concave bays are ideal for funneling cyclones as the storms travel, according to BBC. These bays, paired with a high sea surface temperature, are the perfect criteria for extreme cyclones.
But hurricanes in the Atlantic also are increasing in strength — and climate change may be the cause, according to a June 2020 paper published in the journal Proceedings of the National Academy of Sciences. Researchers studied 39 years’ worth of data to determine that not only are storms getting stronger, but major tropical cyclones also are increasing in frequency. This trend could be a “perfect coincidence of other trends,” according to Live Science, but the models and real-world observations indicate climate change is most likely to blame.