In 1971, Fujita Tetsuya (藤田 哲也), a professor at the Chicago University invented the index: “Fujita scale (F scale),” which measures the wind velocity of tornadoes in the United States. More than one thousand tornadoes a year are recorded globally and 3/4 of them are seen in the United States.
Tetsuya’s index became an international standard.
Moreover, he discovered the downburst (a descending jet stream) in 1975 and saved a lot of lives. Read More »