95th Anniversary of the Fujiwhara effect

Sakuhei Fujiwara (c.1920)
Sakuhei Fujiwhara (c.1920)

In the October 1921 issue of the Quarterly Journal of the Royal Meteorological Society, Sakuhei Fujiwhara, of the Central Meteorological Observatory of Tokyo, published an article on theoretical considerations of the interactions of a  vortex in a fluid, in particular between two vortices.  He described how when two vortices approached each other they would tend to orbit around a common center point.  This interaction came to be known as the “Fujiwhara Effect”.

Forecast tracks
Forecast tracks of Matthew and Nicole

It has been noted that some of the computer forecasts of Hurricane Matthew and Tropical Storm Nicole demonstrate just such an interaction.

Fujiwhara, Sakuhei (1921). “The natural tendency towards symmetry of motion and its application as a principle in meteorology”. Q. J. R. Met. S. 47 (200): 287–293.