In the previous article, we mentioned the differences between extratropical and tropical cyclones. But what is the difference between hurricane, typhoon, cyclone and tornado?
Hurricane, typhoons and cyclones are just different names for the same objects. They all mean tropical cyclone, but historically the cyclones are distinguished by the region of appearance. It is an object in the atmosphere which has very low pressure in its centre and therefore causes the wind to spin around.
What is a tornado?
Tornado is a phenomenon which appears in convective storms mostly in supercells. it is created differently than the tropical cyclone. It forms from a downburst in a storm when cold air subsides and warm air rises from the Earth. Tornado is even smaller and lasts not as long as a cyclone.
What direction hurricane spins
Hurricane is widely known for its destructive power. The destruction is mainly caused by its winds speed, which reaches 74 mph (119 km/h) and more. The casualties caused by tropical cyclone going from ocean to land depend on the orography of the coast and direction of the wind circling around its centre. So, what direction does a hurricane spins?
Hurricane or a tropical cyclone is a low-pressure object in the atmosphere. Simply said, the centre has the lowest pressure and therefore the wind should go straight from the edge to the centre. This could be true only if the Earth doesn’t spin. Since the Earth rotates every 24 hours around its axis, we must add physics in a form of Coriolis force to our little model.
Coriolis force is a force that affects only those particles that move in a system that is moving itself. Even when you walk down the street, the Coriolis force is present, but it is small due to slow movement and friction. On the northern hemisphere, the Coriolis force causes all particles to change the direction of movement slightly to the right, on the southern hemisphere, to the left.
Adding the Coriolis force to our little model, the wind on the northern hemisphere will be moving still radially from the edge to the centre of the cyclone, but it will also turn right (in the southern it’s to the left). The little deviation in the motion causes the wind in the northern hemisphere to circle anticlockwise and in the southern hemisphere to circle clockwise.
Where do hurricanes form
Hurricane is a name for tropical cyclones in the Atlantic Ocean and north-eastern Pacific Ocean. The Hurricanes in the Atlantic Ocean form close to the shores of Africa. The best place there is near Sahara where are extreme differences between hot and dry desert and colder and humid ocean. There are common waves in the atmosphere too, which is one of the seven conditions needed to form a tropical cyclone.
In the north-eastern Pacific Ocean, the hurricanes form near the west shores of Middle America (from Panama to Mexico) or can be once again strengthened hurricane from the Atlantic. They all head westerly and therefore they usually end in the Pacific Ocean. They can in rare situations turn back when going northerly and reaching the westerlies.
And there is one interesting fact to add. The English word “hurricane“ originates in Mayan god of wind, storm and fire “huracán“. The Carib Indians took the name and gave it to their god of evil, “huricán“. And then the Spanish came and turned it back into “huracán“, which is a Spanish word for a hurricane since then. The last modification was in the 16th century by the English to “hurricane“.
Where do typhoons form
In the north-western Pacific Ocean basin, tropical cyclones are called typhoons. They all form in the North Pacific Ocean a few degrees from the Equator and goes as usually all tropical cyclones westerly. The typhoons can move slightly to the north and sometimes they reach westerly winds that cause the typhoons to move back to the east. The returning cyclones disappear in the Pacific and causes.
The reason for naming the cyclones “typhoons” and not “hurricanes” was linguistic. The word “typhoon“ has a bit of difficult origin. It is thought to be old Mandarin Chinese word for big wind “dàfēng“ that evolved through Cantonese word “daai fung“ to Hakka “thai-fûng“ and then to modern common known word “typhoon“. But it is quite interesting that an ancient Greek name for the father of winds is “Tuphôn“. Do you think they could have an impact on the word or is it just coincidence?
South Pacific and Indian Ocean: Simply a cyclone
In South Pacific, Cyclone is mostly used the name for tropical cyclones or cyclonic storms. The cyclones form in the South Pacific Ocean a few degrees away from the Equator and move to the west mostly threatening Australia.
In the Indian Ocean, the Cyclones form in the Bay of Bengal again a few degrees from the Equator and moves westerly or northerly.
The term “Cyclone” is a simply short version of words “Tropical Cyclone”. And the word “Cyclone” has a straight origin. It comes from Greece, where the word for “moving in a circle” is “kyklos“.
Štěpán Šubík
Prague based student of meteorology eager for science, who likes to learn, but also wants to live to the fullest every day. Follow me on Twitter.
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