The Fujiwhara Effect
2017-09-19 15:22:06.000 – Taylor Regan, Weather Observer
A few weeks ago, I wrote a post about the formation of hurricanes, to usher in the start of the hurricane season. Since then, we’ve seen multiple tropical cyclones form, even concurrently! Sometimes, these systems appear to revolve around each other as they move across the oceans. This is known as the Fujiwhara effect, after Japanese Meteorologist Sakuhei Fujiwhara, who first observed the phenomenon in a paper in 1921 describing the motion of vortices in water.
As the paths of two tropical cyclones pass within proximity of each other, they begin to interact. Fujiwhara found that as tropical cyclones approach each other, they begin to rotate counter-clockwise about a central point, with the degree of interaction increasing as the distance between the two systems decreases. Further studies have shown that the degree of interaction is dependent not only on the distance between the storm centers but also the strength and size of each storm as well as the overlying environmental setup.
Taylor Regan, Weather Observer
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