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Fujita, Tetsuya

Tetsuya Fujita

A master of observation and detective work, Japanese-American meteorologist Tetsuya "Ted" Fujita (1920–1998) invented the F-Scale tornado damage scale and discovered dangerous wind phenomenon called downbursts and microbursts that are blamed for numerous plane crashes. In a career that spanned more than 50 years in Japan and the United States, Fujita is considered one of the best meteorological detectives.

Showed Early Aptitude for Science

Tetsuya Fujita was born on October 23, 1920, in Kitakyushu City on the southern island of Kyushu in Japan. His first name meaning "philosopher," Tetsuya was the eldest child of Tomojiro, a schoolteacher, and Yoshie (Kanesue) Fujita.

Fujita attended Meiji College in Kyushu where he majored in mechanical engineering, and was also interested in geology, volcanoes, and caves. With this love of science, he developed a skill for visualizing weather and drawing three-dimensional topographical projections. Fujita graduated from Meiji College in 1943 with the equivalent of a bachelor's degree in mechanical engineering.

Investigated Rubble at Hiroshima and Nagasaki

About a month after the Americans dropped an atomic bomb on Hiroshima on August 6, 1945 and another one on Nagasaki on August 9, the 24-year-old Fujita traveled to the two cities to investigate the effects of the bombs. He picked through the rubble and analyzed the unique starburst burn patterns perpetrated by the bombs. Working backwards from the starburst patterns, he calculated how high above the ground the bombs were exploded. At Nagasaki, he used scorch marks on bamboo vases to prove that only one bomb had been dropped on that city. Fujita's observations and experience at the bomb sites became the basis of his lifelong scientific research.

Postwar Research in Thunderstorms and Tornadoes

In this postwar environment, Fujita decided to pursue meteorology and in 1946 applied for a Department of Education grant to instruct teachers about meteorology. He took several research trips. On one excursion, he walked up to a mountain observatory during a thunderstorm to record wind velocity, temperature, and pressure. He discovered that downdrafts of air inside the storm made the storm spread out from a dome of high pressure, which he dubbed a "thundernose."

On another trip in 1947, Fujita mapped the motion of a thunderstorm using lightning timings, and found that the storm had three separate subcenters of lightning activity. With his research, Fujita had disproved the smooth path of storms explained in textbooks of the day and began to remake thunderstorm theory.

The first tornado damage that Fujita observed was on September 26, 1948, on Kyushu, which rarely experienced such storms. After he began to give lectures to the Weather Service on his various research findings, he decided he should publish them. He bought an English-language typewriter so he could translate his work into English.

Corresponded with Horace Byers in Chicago

After lecturing on his thundernose concept, his colleagues gave him a meteorological journal they had taken out of the trash from a nearby American radar station. So fascinated was Fujita by the article, "The Nonfrontal Thunderstorm," by meteorologist Dr. Horace Byers of the University of Chicago, that he wrote to Byers. He also sent Byers two of his own research papers that he had translated, one on microanalysis and the other on his thundernose concept.

In Chicago, Byers had been playing a key role in coordinating the scientific program Thunderstorm Project, whose aim was to find the structure of storms. Byers was impressed with the work of the young Japanese meteorologist, especially since Fujita, with just paper, pencil, and a barometer, had proven some of the same fundamentals of storm formation that the Thunderstorm Project discovered after spending millions of dollars.

In 1953, Byers invited Fujita to the University of Chicago to work as a visiting research associate in the meteorology department. A 33-year-old suffering from postwar depression and a stifling lack of intellectual encouragement in Japan, Fujita relished his chance to work in meteorology in the United States. His difficulty with English only strengthened his ability to communicate through his drawings and maps. By 1955 Fujita was appointed to the faculty at the University of Chicago.

Developed Concept of Mesoanalysis

During this time, Fujita published his landmark paper on mesoanalysis. Working with Dr. Morris Tepper of the Weather Bureau in Washington, D.C., Fujita analyzed barograph traces in connection with tornado formation. Using his meticulous observation and measuring techniques on a 1953 tornado that struck Kansas and Oklahoma, he discovered highs and lows in the barograph traces that he called "mesocyclones." His newly created "mesoscale" plotted individual high pressure centers created by thunderstorms and low pressure areas. The scale could analyze virtually anything between one mile and 600 miles wide.

As a master of observation, Fujita relied mostly on photographs for his deductive techniques. In 1957 a particularly destructive tornado hit Fargo, North Dakota. As the storm moved rather slowly, many people and news agencies took hundreds of photos and film footage. Fujita gathered 150 of these pictures, manipulated them to a single proportional size, then analyzed the movement of the storm and cloud formations in one-minute intervals. He was able to identify the storm's mesocyclone and its wall cloud and tail cloud features, which he described in his paper "A Detailed Analysis of the Fargo Tornado of June 20, 1957."

Created the F-Scale for Tornado Damage

In April 1965, 36 tornadoes struck the Midwest on Palm Sunday. Fujita took extensive aerial surveys of the tornado damage, covering 7,500 miles in the air, and found that mesocyclones explained how one storm path could pick up where another had ended, leaving an apparently seamless track of tornadoes hundreds of miles long. Fujita's experience on this project would later assist in his development of the F-Scale damage chart.

In 1971, Fujita formulated the Fujita Tornado Scale, or F-Scale, the international standard for measuring tornado severity. Earlier, meteorologists recorded only the total number of tornadoes and had no standardized way to measure storm strength or damage. The Beaufort Wind Scale ended at 73 miles per hour, and the low end of the Mach Number started at 738 miles per hour; Fujita decided to bridge the gap with his own storm scale.

Characterizing tornado damage and correlating that damage with various wind speeds, the F-Scale is divided into six linear steps from F0 at less than 73 miles per hour with "light damage," such as chimneys damaged and shallow-rooted trees turned over, up to F5 at 318 miles per hour with "incredible damage," such as trees debarked and houses torn off foundations. Fujita published his results in the Satellite and Mesometeorology Research Project (SMRP) paper, "Proposed Characterization of Tornadoes and Hurricanes by Area and Intensity."

While the F-Scale was accepted and used for 35 years, a thorough engineering analysis of tornado damage had never been conducted for the creation of the F-Scale. A team of meteorologists and wind engineers developed the Enhanced F-Scale, which was implemented in the United States by the National Oceanic and Atmospheric Administration (NOAA) in February 2007.

Discovered Downbursts and Microbursts

After developing the F-Scale, Fujita gained national attention, and he even earned the nickname "Mr. Tornado." In 1972 he received grants from NOAA and NASA to conduct aerial photographic experiments of thunderstorms to verify data collected by the new weather satellites put into orbit. He studied the tops of thunderstorms, and he helped develop a sensing array of instruments used by tornado chasers on the ground.

In 1974, Fujita discovered a phenomenon he called downbursts. With help from the National Severe Storms Laboratory (NSSL), he studied the 2,584 miles of damage caused by the 148 tornadoes occurring during the Super Tornado Outbreak of April 1974. He had determined that downdrafts from the storms actually had enough strength to reach the ground and cause unique damage patterns, such as the pattern of uprooted trees he had observed at Hiroshima so long ago. Fujita noted in The Weather Book, "If something comes down from the sky and hits the ground it will spread out … it will produce the same kind of outburst effect that was in the back of my mind from 1945 to 1974."

Although his downburst theory was met with skepticism at first, in 1978 the National Center for Atmospheric Research aided Fujita in his research, which detected 52 downbursts in Chicago in 42 days. As most damage had typically been attributed to tornadoes, Fujita showed it had really been caused by downbursts. He said in The Weather Book," After I pointed out the existence of downbursts, the number of tornadoes [listed] in the United States decreased for a number of years."

Following the Eastern Airlines flight 66 crash at Kennedy Airport on June 24, 1975, Fujita once again was called in to investigate if weather patterns played a part in the crash. With the new Dopplar radar that had been in use for only a few years, Fujita was able to gather incredible amounts of data. He discovered a type of downdraft he called microburst wind shear, which was rapidly descending air near the ground that spread out and could cause 150 mile per hour wind gusts, enough power to interfere with airplanes.

As a direct result of Fujita's research on microbursts, Doppler radar was installed at airports to improve safety. Research meteorologist James Partacz commented in the University of Chicago's Chicago Chronicle, "This important discovery helped to prevent microburst accidents that previously had killed more than 500 airline passengers at major U.S. airports." The fact that Fujita's discoveries led to the saving of hundreds of lives filled him with joy. He noted in The Weather Book, "When people ask me what my hobby is, I tell them it's my research. I want to spend the rest of my life in air safety and public safety, protecting people against the wind."

Saw His First Tornado

Ironically, "Mr. Tornado," the man who had developed the F-Scale to rate the damage caused by tornadoes, never actually witnessed a live tornado until June 12, 1982. While working on the Joint Airport Wind Shear (JAWS) project in Colorado, Fujita was sitting at a Dopplar radar station, "when I noticed a tornado maybe was coming down. I told all the radars to scan that area. My first sighting of a tornado was one with the best tornado data ever collected," he said in The Weather Book.

In another quirk of Fujita's research, he distrusted computers and rarely relied on them. The bulk of his observation was with photographs, paper, and pencil. Chicago meteorologist Duane Stiegler who worked with Fujita commented in the New York Times, "He used to say that the computer doesn't understand these things." Today, computer modeling and automated mapping are the dominant tools of meteorologists.

Left Enduring Legacy

In his later years, Fujita investigated the July 1982 crash of Pan American 727 in New Orleans, the 1985 Delta flight 191 crash at Dallas-Fort Worth, and the hurricanes Alicia in 1983, Hugo in 1989, and Andrew in 1992. He was named director of the Wind Research Laboratory at the University of Chicago in 1988. A year later, the university named him the Charles Merriam Distinguished Service Professor.

After a long illness Fujita died on November 19, 1998, at his home in Chicago at the age of 78. Partacz said in the New York Times, "He did research from his bed until the very end." Well respected by his peers, Fujita received an outpouring of honors and accolades after his death. The American Meteorological Society held a memorial symposium and dinner for Fujita at its 80th annual meeting. In 2000, the Department of Geological Sciences at Michigan State University posthumously made Fujita a "friend of the department." That same year, the National Weather Association named their research award the T. Theodore Fujita Research Achievement Award.

Jim Wilson, a senior scientist at the National Center for Atmospheric Research, said of Fujita in the Chicago Chronicle, "There was an insight he had, this gut feeling. He often had ideas way before the rest of us could even imagine them."


Notable Scientists: From 1900 to the Present, Gale Group, 2001.

Scientists: Their Lives and Works, Vols. 1-7. Online Edition. U*X*L, 2004.

Williams, Jack, The Weather Book: An Easy to Understand Guide to the USA's Weather, Vintage Books, 1997.


Chicago Tribune, May 10, 1990.

Discover, May 1983.

National Geographic, April 1972.

New York Times, November 21, 1998.

Weatherwise, May/June 1999.

University of Chicago Chronicle, November 25, 1998.


"A Tribute to Dr. Ted Fujita," Storm Track, (December 18, 2006).

Fujita, Kazuya, "Tetsuya 'Ted' Fujita (1920–1998): 'Mr. Tornado,'" Michigan State University,∼fujita/tornado/ttfujita/memorials.html (December 18, 2006).

"Fujita Tornado Damage Scale," Storm Prediction Center, National Oceanic and Atmospheric Administration, (December 18, 2006).

"Tetsuya Theodore Fujita," The Tornado Project, (December 18, 2006).

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