Thursday, January 22, 2009

The Fujiwhara Effect

When two hurricanes get too close to one another, a strange thing happens. The interaction is described by the Fujiwhara effect.
When two cyclones approach one another (get within a distance of about 1,450 miles) the two cyclone begin to orbit around a centroid. The centroid is located where the mass is balanced. The stronger a cyclone, the "heavier" it is. This situation isn't unlike Pluto and Charon, who orbit around a point just off Pluto's surface. Since Pluto is heavier, it dominates the interaction, and orbits closer to the center. Eventually one cyclone destroys the other, or, more rarely, they merge into one cyclone.

A few notable examples include an occurrence between Typhoon Pat and Tropical Storm Ruth in 1994. They completed one orbit around each other before merging into one cyclone. The most recent example in the Atlantic is Hurricane Wilma absorbing Tropical Storm Alpha in 2005.

Two cyclones orbiting around each other in 1974.


Anonymous said...

Is it possible for two black holes 2 experience a Fujiwhara effect? I know storms feed on solar energy in ocean, and conditions have 2B just right, since 1 can't sneak up on the other, (water cold in wake). Perhaps star matter could be solar energy in this case. Since pluto and moon sustain the interaction, could not two black holes? R there examples?

Louis said...

An analogous situation could indeed occur with black holes, with gravity providing the attractive force. In many of these situations, a black hole and another body (such as a main sequence star) orbit each other, and the black hole sucks material off of its companion star. In the case of two black holes, such a situation could arise when two galaxies merge, and their central black holes orbit one another. NGC 6240 is a possible example. As with the Fujiwhara effect, the orbits of these black holes would slowly decay until they eventually merge into one.

Professor Quibb