This week's episode of Grammar Grater addresses a topic we've heard so much about in the news. On May 2, Myanmar (also known as Burma) was struck by Cyclone Nargis. Tropical storms have made the headlines many times in recent years, but we come across various words to describe them: cyclone and hurricane, to name but two.
To help us understand this better, we spoke to Minnesota Public Radio's chief meteorologist, Paul Huttner.
Equipped with his Glossary of Meteorology, Huttner explains that a cyclone is defined as a cyclonic circulation in the atmosphere, and the word cyclonic simply means a counterclockwise circulation in the northern hemisphere. "So basically any cyclonic circulation would qualify as a cyclone and there are many different types and scales of cyclones," he says.
A tornado, Huttner says, is one type of cyclone. "Cyclones generally have low barometric pressure," Huttner explains, "so they're sometimes called 'lows,' and low pressure is generally associated with stormsso cyclone kind of equals storm."
The tropical storm that struck Myanmar was a called a cyclone, but given the different names for tropical storms, it appears there are many types. Huttner was quick to clarify this. "Meteorologically, they're all the same," he says. "There is one type of storm that produces what we would call a tropical cyclone. That is the big generic header name for all of these different things we hear about called hurricanes or typhoons or cyclones."
According to Huttner, these different names for tropical storms are geographic in their naming; that is, different parts of the world use different names. In the Atlantic, the Caribbean and the Eastern Pacific, these tropical storms are called hurricanes. West of the International Date Line in the Pacific Ocean, they're called typhoons. In the southwest Pacific and the Indian Ocean, these storms are called severe tropical cyclones. Sometimes a name change happens when a storm crosses certain degrees of longitude. "It gets complicated, believe me," Huttner says.
Huttner says that there have been other regional names in the past. "Baguios in the Philippines, even willy-willies in Australiakind of nicknames for these severe cyclones."
With so many storm names being used, Huttner has some advice for keeping them all straight. "The biggest thing to remember is that tropical cyclone is the big overall term for any tropical stormshurricanes, that kind of thing," he says. "That's the generic header."
Paul Huttner is the author of the MPR weather blog, Updraft, and he hosts the weather podcast, Jet Streaming.
Sources: Glossary of Meteorology, edited by Todd S. Glickman.
Music from this Episode: "Once Upon a Time" by Air; "Sing a Powerful Song" by Saw Doctors.