What's the difference between hurricanes, cyclones and typhoons? - CBBC Newsround
Now that you know the difference between a hurricane, typhoon, and cyclone, you may be wondering how these differ. Aug 7, What Is the Difference Between a Cyclone, Typhoon, and Hurricane? A tropical cyclone is a warm-core system that has a warm, humid. Sep 14, "Once a tropical cyclone reaches maximum sustained winds of the relationship between climate change and hurricanes a complex one.
The one pictured above was the "Chiclone" of Octoberwhich wound up being one of the most intense extratropical cyclones ever recorded in the United States its pressure dropped to near millibars.
Now that we've established that all low pressure systems are cyclones, we can look at what different regions of the world call ones that are tropical in nature. The embarrassingly-bad map above shows the very rough cutoff points for different names. Around North America, we call tropical cyclones "hurricanes. Anything lower than that and it's a buffet of different names. The dividing line for whether a tropical cyclone is called a hurricane, typhoon, or simply a cyclone is based on latitude and longitude.
A perfect example is Hurricane Genevieve. Once it crossed that line, it went from Hurricane Genevieve to Super Typhoon Genevieve simply because it crossed from one region into the other. Same storm, different name. If a storm like Genevieve forms in the CPHC's area of responsibility and moves west over the International Date Line, it becomes the responsibility of Japanese Meteorological Agencywhich is responsible for all tropical systems that form in the northwestern Pacific Ocean.
But what, exactly, is a typhoon? Here, an explanation of this type of storm. They're all the same, officially tropical cyclones. But they just use distinctive terms for a storm in different parts of the world. Hurricane is used in the Atlantic, Caribbean Sea, central and northeast Pacific. They are typhoons in the northwest Pacific.
In the Bay of Bengal and the Arabia Sea, they are called cyclones. Tropical cyclone is used in the southwest India Ocean; in the southwestern Pacific and southeastern India Ocean they are severe tropical cyclones. A storm gets a name and is considered a tropical storm at 39 mph 63 kph. It becomes a hurricane, typhoon, tropical cyclone, or cyclone at 74 mph kph. There are five strength categories, depending on wind speed.
The highest category is 5 and that's above mph kph. Hurricane Ike grew to a Category 4 hurricane temporarily but the Caribbean islands took away its steam. Once a hurricane hits land it loses its source of power, namely, the heat and moisture of the ocean. NOAA What happens during an extratropical transition? As it moves out of the tropics, a storm may encounter increased vertical wind shear, changes in humidity over distance, and decreased or quickly changing sea surface temperatures—all conditions that disrupt hurricanes.
Instead of rotating symmetrically around a core, the storm disarranges itself and spreads out to a much larger size. The high-level canopy layer of clouds, which is characteristic of a hurricane, no longer resembles a symmetrical pinwheel in satellite images.
The structure of the storm starts to look like it does when a warm and a cold front meet each other—a comma shape instead of a spiral shape. As it enters the mid-latitudes, the storm gets caught in the prevailing westerly winds, and it picks up speed, accelerating from perhaps 11 miles per hour in the tropics to 45 miles per hour at higher latitudes. After the extratropical transition, a storm can still generate lots of rainfall and large ocean waves, and sometimes even hurricane-force winds.
A mid-latitude cyclone can be just as dangerous as a hurricane under certain circumstances, even though its winds are not as fast. But it too will eventually lose steam.
In remnants of Tropical Storm Bill dropped over 10 inches of rain in one night in southern Oklahoma, a prime example of how cyclonic storms can cause major damage even far from the coast. Certainly, humans are capable of changing the natural world in many ways, from damming mighty rivers to breaking shipping passages through Arctic ice. People have wondered if humans could stop a hurricane by seeding it with silver iodide, placing substances on the ocean surface to inhibit the ocean-air heat transfer, cooling surface waters with ice, pumping cold water to the surface from lower down in the ocean, adding moisture-absorbing substances to the hurricane, and even attacking it with nuclear weapons.
The other ideas are also impractical. We can instead opt to spend resources on predicting them and building infrastructure to resist them. Variation Across the Globe The World Meteorological Organization designates seven different hurricane formation basins in the world.
A map of the hurricane basins around the globe. Hurricane-level storms that occur in the northern Atlantic Ocean and northeast Pacific Ocean are called hurricanes, while those in the Northwest Pacific are called typhoons. In other parts of the world, these storms are called severe tropical cyclones, severe cyclonic storms, and tropical cyclones.
This can get confusing, but the key similarity is that they all gain their power from tropical warmth. Calling hurricanes different things in different places is a matter of convention.
Hurricanes, typhoons and cyclones: What's the difference? - BBC News
However, there are substantive differences in the hurricane activity that occurs in different hurricane basins. For one thing, hurricane season varies from basin to basin. And, notably, the North Indian season has two peaks—one in May and one in November. The dip in hurricane activity between them is due to the way the monsoon affects wind shear.
Basins also differ in the number of hurricanes they see every year.
Hurricanes, Typhoons, and Cyclones | Smithsonian Ocean
In the Atlantic basin, the annual average is about six hurricanes. The Northwest Pacific sees by far the largest number of hurricanes each year, with an average of More hurricanes occur in the Northern Hemisphere 69 percent than the Southern 31 percent. Furthermore, of the hurricanes occurring in the Northern Hemisphere, 57 percent occur in the Pacific Ocean and 31 percent occur in the Indian Ocean, with only 12 percent occurring in the Atlantic.
While there are many different names for hurricanes across the globe, keep in mind that just because a storm swirls in a massive cyclone doesn't mean it is a hurricane from the tropics—there are other types of cyclones. Mid-latitude cyclones occur when a mass of cold air collides with a mass of warm air. Hurricane Tracks Knowledge of major atmospheric circulation patterns in different basins allows us to make generalizations about the most common tracks of hurricanes.
For example, a hurricane that forms in the tropical Atlantic will typically be blown westward by the easterly trade winds that dominate the low latitudes.
If you look at the aggregate of the paths of all Atlantic hurricanes over the past century or so, they will show you a broad-brush version of this recurvature. North Atlantic tropical storms and hurricanes NOAA General hurricane tracks can similarly be sketched for other hurricane basins, largely based on major atmospheric circulation patterns. For example, hurricanes in the Northwest Pacific basin tend to move westward towards the East China Sea and then recurve northward and northeastward around the area of high pressure in the Northern Pacific Ocean.
Those in the Southwest Indian basin tend to proceed more directly westward across the Indian Ocean towards Madagascar and the eastern coast of continental Africa. Infor example, a hurricane spotted off the coast of Florida was later reported to be moving north and northeast, seemingly following the typical Atlantic recurvature and remaining out at sea. But the next day, the hurricane hit Long Island, New York, bringing with it a foot wall of water called a storm surge and killing hundreds of people.
Studying Hurricanes The Hurricane Forecast Over the past thirty years, we have gotten dramatically better at predicting the tracks of hurricanes—what paths they will follow and where they will hit land. In the late s, the U. Nowadays, the NHC only misses by about miles. Except for sending pilots to fly through a hurricane and measure wind speed, using an algorithm called the Dvorak technique to interpret satellite images of hurricane shape is currently the best way to judge its intensity.
The satellites use specialized radar and microwave technology to map the precipitation of a hurricane and help scientists study the storm. This scan is of Hurricane Patricia in For instance, when Hurricane Irma hit Florida init made a big difference to the people living there whether the landfall was predicted for the west coast of the peninsula or the east coast of the peninsula.
The answer lies in a subdiscipline of mathematics called chaos theory that was developed during the s by a meteorologist named Edward Lorenz. It tells us that a very small variation in initial conditions can produce a huge and sometimes unexpected variation in eventual outcomes.
Typhoon? Hurricane? Cyclone? Here's the difference
Lorenz called this the butterfly effect—imagine a butterfly in Brazil stirring up a tiny amount of air by flapping its wings, influencing a tornado in Texas several weeks later. On September 8, it was still unclear whether Hurricane Irma would hug the eastern coast of Florida or steer towards the western coast along the Gulf of Mexico, leading many Floridians on both coasts to question whether they would bear the brunt of the storm.
Today, meteorologists use a range of models as well as their own savvy to make the very best predictions they can.What is a hurricane and where does it form? - Hurricane video for kids
Statistical models aggregate decades of historical data to predict what a hurricane is likely to do based on how past hurricanes have behaved. Dynamical models use powerful computers to model the atmosphere using equations and data from satellites, on-the-ground measurements, and hurricane flyers. Meteorologists use their expertise to sort through all the data from the field and results from the models, and then they make a prediction. In addition to predicting where a hurricane will go scientists must also predict to what extent it will intensify, and this too is a tough job.
In general, scientists use data about how warm the ocean is, how much moisture there is in the air, and how consistent the winds are throughout the layers of the atmosphere to determine how much a hurricane will build in intensity.
But there are other, smaller processes like thunderstorm formation, rain formation, and ice formation that can affect that intensification process.
Hurricane Michael ofthe third strongest storm to hit the continental United States, is a prime example of such intensification. The storm jumped from a Category 2 to a Category 5 in only 24 hours, an intensification that proved to be tough to predict.
Researchers from one such study combed through recently translated indigenous Hawaiian newspapers to find references to natural disasters, a process that revealed a reference to the notoriously devastating hurricane in By piecing together damage accounts from across the Hawaiian Islands the historians determined the trajectory and intensity of the hurricane.
Many things can throw a wrench into hurricane track predictions. First described by Japanese meteorologist Fujiwhara Sakuhei inthe Fujiwhara effect occurs when two hurricanes get within miles km of each other. Once they are within that distance, they will rotate around a point directly between their centers, like dancers circling each other. If the storms are about the same size, the interaction might simply alter their trajectories before they break apart.
On the other hand, if one storm is much smaller than the other, then the larger storm might absorb the smaller one once they get close enough. Meteorologists classify tropical cyclones depending on their wind speed. Once the winds reach 74 mph km per hourthe storm graduates to hurricane status. Usually, that is the wind speed necessary for an eye to form in its center.
Meteorologists sort hurricanes into five categories depending on their maximum sustained wind speed. Versions of the Saffir-Simpson Scale are used officially in the U. Terrifying Category 5 storms have petered out at sea without doing any human damage at all. Hurricanes and the Natural World When we think of hurricane damage, we tend to think of the way these storms impact people and human infrastructure—and for good reason. But even when hurricanes barely touch humans, they can wreak havoc on the natural world.
A hurricane can leave its mark by rearranging geography. Hurricanes change coastlines, uprooting trees with their powerful winds and moving earth with the force of water.
When Hurricane Agnes hit the Chesapeake Bay init reconfigured the hydrology of the area, eroding away the mouths of tributaries to the Bay and transporting huge amounts of sediment upstream.