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Fujita, Tetsuya Theodore


(b. Kyushu, Japan, 23 October 1920; d. Chicago, Illinois, 19 November 1988)


Tetsuya “Ted” Fujita was one of the world’s most famous and successful storm investigators. His contributions to the field are numerous, but he is most remembered for his invention of the Fujita (F) scale for tornadoes and his extensive studies on microbursts. His identification of downbursts revolutionized the understanding and full impact of strong straight-line thunderstorm winds. Fujita was also a forensic mesometeorologist, photographer, and a scientific cartographer. Among his talents were photography and photogrammetry (still movie, satellite, video), technical illustration and scientific cartography, classical simple measurements (depth of snow, his own blood pressure), mesoscale analysis, reconstruction of surface wind fields from damage patterns on a wide range of scales, inferring storm dynamics from imagery and estimated surface winds (tropical storms, thunderstorms, and downbursts) and the climatology of tornadoes.

Early Years in Japan . Tetsuya Fujita was born in Sone Town, now part of South Korea, on the island of Kyushu, Japan, on 23 October 1920, the eldest child of Tomojiro and Yoshie Fujita. He developed an interest in mapping early in his life; Japanese prewar topographic maps had many blank areas due to military secrecy, including many near his home, and he began mapping these areas. Fujita earned a bachelor’s degree in mechanical engineering in 1943 from Meiji College of Technology. He later recalled that his father’s last words saved his life. Fujita had wanted to attend Hiroshima College, but his father insisted that he attend Meiji College. Had he attended Hiroshima College, he might have been killed by the first atomic bomb dropped by U.S. forces near the end of World War II.

In 1945 Fujita was teaching physics at Meiji College. In September of that year, the Japanese government sent him to survey the destruction at both Hiroshima and Nagasaki to determine the number of bombs and the height of their detonation by using the starburst method, which matches the pattern of knocked-down trees and other structures to the starburst shape. He observed the shock-wave effects on trees and structures in these areas. In April 1946 he surveyed a volcanic eruption at Sakurajima, and in 1947 he conducted studies of downflows in thunderstorms using data from Seburiyama.

Fujita conducted his first tornado survey—of the Enoura tornado near Saga in Kyushu—on 26 September 1948. He gave briefings on his findings from this survey and soon realized that they should be published, and the experience motivated his interested in weather. In August 1950, he sent copies of his papers on his findings from this tornado survey to Horace Byers, chairman of the Department of Meteorology at the University of Chicago. Byers had just completed an extensive U.S. government–sponsored study of thunderstorms, and he was impressed by Fujita’s work. In May 1951 Shigekata Shono sponsored Fujita’s research through the University of Tokyo. In August 1952 Fujita completed his doctoral dissertation, and he formally received his degree in 1953 from the Kyushu Institute of Technology with a dissertation on “Analytical Study of Typhoons.” His doctoral thesis was a study of the damage from several typhoons that struck Kyushu Island in three consecutive years.

Early Years at the University of Chicago . In 1953 Byers invited Fujita to a two-year research appointment at the Department of Meteorology at the University of Chicago. He arrived in Chicago on 13 August 1953. In 1955 Byers suggested that he stay and become a permanent member of the department. Fujita returned to Japan to obtain an immigrant visa and returned to the United States with his family in July 1956 (he had married Tatsuko Hatano in 1948). His official title at this time at the University of Chicago was research professor and senior meteorologist.

Thunderstorm research is another topic that highlights Fujita’s career. He wanted to see them from above, from the side, and from below. His interest in thunderstorms led to the application of his microanalysis techniques to barograph traces in order to correlate tornado formation with pressure jump lines. This was the introduction of mesoanalysis (study of features on a horizontal scale of 10–100 km). During this time he coauthored the landmark paper “Mesoanalysis,” which was published in 1956 as U.S. Weather Bureau research paper number 39. He began his research in the old building of the Department of Meteorology, where he established the Severe Local Storms Project (SLSP). The mesoanalysis of thunderstorms resulted in Fujita’s primary focus on tornadoes during the twenty-year period from the 1950s to the mid-1970s.

Research Leading to the Fujita Scale . Although Fujita surveyed his first tornado damage in 1948, his study of the 20 June 1957 tornado in Fargo, North Dakota, placed him in the forefront of tornado research. His detailed description of this outbreak, published in 1960, has become a classic in the field of storm study below the continental scale of synoptic meteorology and beyond the resolution of numerical models. He coined the terms wall cloud and tail cloud during this study. SLSP became the Meteorology Research Project (MRP) in 1961 and moved into a location next to the old weather service offices. In 1962 Fujita was promoted to associate professor and subsequently to full professor in 1965. In 1964 the MRP was changed to the Satellite and Mesometeorology Research Project (SMRP). In the 1960s Fujita analyzed the Palm Sunday outbreak of 11 April 1965, constructing maps from thousands of aerial photographs of storm damage, and he concluded that certain tornadoes must contain more than one vortex and propagate as “families.”

In 1968 Fujita and his wife divorced, and he also became a U.S. citizen. At this time he added the middle name Theodore (Ted) to his name. In 1969 he was remarried to Sumiko Yanamoto of Tottori, Japan.

Among Fujita’s many interests, tropical cyclones were a lifelong passion, dating back to his doctoral thesis in 1952. Fujita did his first major study of a hurricane in 1949 with Typhoon Della and later he conducted his first hurricane survey on Hurricane Camille in August 1969. He was able to display concepts in his damage surveys that were easy to visualize, even for a layperson. His multicolor damage survey maps of hurricanes and tornado outbreaks remain classics. Fujita’s last hurricane survey work concerned Hurricane Andrew and Typhoons Omar and Iniki in 1992.

In 1971 Fujita, along with Alan Pearson of the National Severe Storms Forecast Center, proposed what became known as the Fujita scale for tornado intensity, which classifies tornadoes based on their wind speed and resultant damage. Fujita recognized that estimates of wind speed associated with described damage would be demanded, so he provided a wind speed range for each scale value. The wind speed range extends from that of a violent hurricane to sonic speed. The Fujita scale and extensive documentation of tornado damage are two of his most important legacies. Later in 1971, he proposed the concept of “suction spots” or “suction vortices” embedded within tornadoes to explain the details of damage patterns observed. He was instrumental in developing the concept of multiple vortex tornadoes (families of tornadoes), which feature multiple small funnels (suction vortices) rotating within a larger parent thunderstorm cloud. Fujita’s work established that most powerful tornadoes were composed of multiple vortices. He based this conclusion on swaths in the debris patterns left by the tornadoes.

On 3 and 4 April 1974, an outbreak of tornadoes occurred in the central United States, killing 315 and injuring 5,484. The SMRP group conducted extensive aerial damage surveys of this “super outbreak” of approximately 148 tornadoes that occurred in eleven southern and midwestern states. He was able to map the entire path in Fujita scale intensity contours.

Fujita and his colleagues flew over more than three hundred tornado damage swaths from 1965 to 1991. He had an ability to sort out damage indicators on the ground and come up with plausible flow patterns. Fujita also had a unique ability to present his analysis in a clear, concise graphical form. He was often called “Mr. Tornado” by his associates and by the media. Even though he was well known for his tornado research, he did not actually see his first tornado until 12 June 1982, when he witnessed several small tornadoes near Stapleton Airport in Denver, Colorado, as part of a National Center for Atmospheric Research downburst study.

Discovery of Microbursts (1975) . During the mid-1970s Fujita shifted his primary focus from tornadoes to microbursts and downbursts, with an emphasis on aviation safety. This shift was due to the crash of Eastern Airlines Flight 66 on 24 June 1975 at New York’s Kennedy Airport, and it launched his socially most significant work, that of the identification and prediction of microbursts (small downbursts). He defined a downburst as a strong downdraft that induces an outburst of damaging winds on or near the ground. The downbursts were later categorized into microbursts and macrobursts according to their scale of damaging winds.

The crash of Flight 66 was one of the worst airline disasters in the United States at the time, killing 122 people. Fujita extensively analyzed the data from Flight 66. He reviewed the radio communications prior to the crash, noting that the pilots had reported high winds on the runway. He analyzed weather conditions, satellite images, radar scans, and weather maps that displayed observations over large areas. In March 1976 he published the results of his study and explained the cause of the crash of Flight 66 as a microburst. At the time, many meteorologists found it difficult to believe that a small-sized downdraft would be capable of generating an outburst of 150 mile per hour winds on or near the ground, focused on a relatively small area of about one-quarter of a mile in diameter. Some claimed that he was mistaking the wind for the gust front of a squall line thunderstorm.

Fujita continued to collect data on microbursts. The first major breakthrough came on 29 May 1978, when Fujita and his colleagues observed their first microburst on a Doppler radarscope near Yorkville, Illinois. Three Doppler radars, deployed in a triangle near Chicago, detected fifty downbursts in forty-two days in the summer of 1978. Microbursts were subsequently identified all over the world, and airplane pilots were trained regarding how to react to them. This information was also used for training meteorologists and ultimately reduced the number of aircraft disasters due to downbursts (small localized down-drafts of air that spreads at the ground). Fujita investigated additional aircraft accidents and launched a series of experiments and major field projects (Northern Illinois Research on Downburst [NIMROD] in 1978, Joint Airport Wind Shear [JAWS] in 1982, and Microburst and Severe Thunderstorm Project [MIST]) in 1986 to definitively identify the microbursts, whose existence had been doubted by many. These studies enabled him to further his studies on wind shear (change in wind direction and speed) phenomena, which were crucial to the understanding of downbursts and microbursts.

By this time, the downbursts and microbursts were studied as a unique phenomenon generated by events such as dry air intrusion. The Joint Airport Weather Studies Project at Stapleton Airport in Denver led to research that was instrumental in understanding the structure and cause of microbursts. Microburst accidents were responsible for killing more than five hundred airline passengers at U.S. airports alone. It was during these investigations that Fujita coined the terms wet and dry microbursts, indicating whether rain had occurred at the surface during the event. Fujita’s work eventually led to the installation of Doppler radars at airports to improve the detection and warning of these events. A mere ten years after Fujita’s discovery of the microburst in 1976, practical lifesaving solutions were in place.

Other Career Highlight . Fujita was also a pioneer in the remote sensing of atmospheric motion. When meteorological satellites were introduced, he developed techniques for the precise analysis of satellite measurements (sequences of images, first from polar orbiting platforms and then from geostationary platforms). After his initial work, the ability to track clouds and relate them to flow patterns in the atmosphere was transferred into routine operations at the national forecast centers. The diversity and large number of Fujita’s ideas may have affected his ability to formally publish much of his work.

In 1988 SMRP was renamed the Wind Research Laboratory (WRL) to better reflect the wide variety of phe

nomena that was studied. This facility included the famous “tornado machine,” the first of its kind to simulate a tornado. This machine was dismantled in the 1990s, and no record of it appears to remain; at the time, no institution was interested in preserving the apparatus.

Fujita retired in September 1990. During his academic career, he mentored a group of students who became leaders in many areas of meteorology, including Roger Wakimoto and Greg Forbes. In 1991 Fujita produced a small booklet with photographs of the WRL. He wrote his Memoirs of an Effort to Unlock the Mysteries of Severe Storms in 1992. In his last years, he concentrated on the study of storm tracks and the El Niño phenomenon. His health started to deteriorate as a result of several illnesses in 1995, and after the summer of 1996 he was unable to work at the office, but continued his work from home until his condition worsened in August 1998. Fujita suffered from diabetes and often had severe pains in his legs; because he never complained about his health, no one outside his family was aware of his chronic condition. During this period, even when he was confined to bed, he continued his research, greatly assisted by James Partacz and Duane Stiegler, and he maintained contacts with the research community. Stiegler recalls that Fujita did not trust computers to conduct his analyses, preferring to do it himself, saying that the computer did not understand these things. His ability to simplify concepts of severe storms was very important in terms of public education. He passed away in his sleep at home in the early morning of 19 November 1998 at age seventy-eight. The WRL was formally closed on 1 October 1999.

The American Meteorological Society held a memorial symposium and dinner at their eightieth annual meeting in Long Beach, California, in January 2000, organized by Fujita’s former students Forbes and Wakimoto. The proceedings of this volume were published in the January 2001 issue of the Bulletin of the American Meteorological Society. Fujita was one of the great severe storms researchers of the twentieth century. His research on severe thunderstorms, tornadoes, hurricanes, and typhoons provided invaluable information and added to our understanding of these phenomena. Fujita’s achievements were fundamental in terms of severe storm meteorology, and he was arguably one of the greatest contributors to mesometeorology and wind science. During his life, he had great insight into the nature and cause of damaging convective storms. His contributions include terminology, damage surveys, the Fujita scale, and downbursts.



“Mesoanalysis: An Important Scale in the Analysis of Weather Data.” U.S. Department of Commerce, Weather Bureau, Research Paper 39 (1956).

“Recent Studies in Mesometeorology.” Journal of the Meteorological Society of Japan, 75th Anniversary Volume (1957): 256–261.

“A Detailed Analysis of the Fargo Tornadoes of June 20, 1957.” University of Chicago, Department of Meteorology, Severe Local Storms Project, Technical Report no. 5, U.S. Weather Bureau (1959).

“Tornadoes and Downbursts in the Context of Generalized Planetary Scales.” Journal of Atmospheric Science 38 (1978): 1511–1534.

“The Downburst: Mircroburst and Macroburst.” SMRP Research Paper 210, University of Chicago (1985).

Memoirs of an Effort to Unlock the Mysteries of Severe Storms. Chicago: Wind Research Laboratory, University of Chicago, 1992.


Cox, John D. Storm Watchers. Hoboken, NJ: John Wiley & Sons, 2002.

Forbes, Greg, and Roger Wakimoto. “Tetsuya Theodore Fujita: Meteorological Detective and Illustrator.” Available from

Fujita, Kazuya. “Tetsuya Theodore Fujita (1920–1998): Biographic Notes.” Produced for the Weather Classroom at University of California, Los Angeles; available from The author is the son of Tetsuya Fujita.

Fujita, Kazuya, James W. Partacz, Duane J. Steigler, and Robert F. Abbey Jr. A Bibliography of the Publications and Research Reports of Tetsuya T. Fujita (1920–1998). SMRP Research Paper 252. University of Chicago (2000).

McDonald, James R. “Theodore Fujita: His Contribution to Tornado Knowledge through Damage Documentation and the Fujita Scale.” Bulletin of the American Meteorological Society 82, no. 1 (2001): 63–72.

Menzel, W. Paul. “Cloud Tracking with Satellite Imagery: From the Pioneering Work of Ted Fujita to the Present.” Bulletin of the American Meteorological Society 82, no. 1 (2001): 3347.

Snow, John T., and Theresa A. Leyton. “Reflections on Ted Fujita: The Relevance of His Many Contributions to Today’s Wind Science.” Invited Keynote address, 11th International Conference of Wind Engineering, Lubbock, Texas, 3 June 2003.

Wakimoto, Roger. “A Tribute to the Works of T. Theodore Fujita.” Bulletin of the American Meteorological Society 82, no. 1 (2001): 911.

Sepideh Yalda

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Fujita, Tetsuya Theodore (1920-1998)

Fujita, Tetsuya Theodore (1920-1998)

Japanese-born American meteorologist

In 1974, Theodore Fujita became the first scientist to identify microburst wind shear , a particularly intense and isolated form of wind shear later blamed for several devastating airline accidents in the 1980s. The development of Doppler radar allowed Fujita to track and explain the microburst phenomenon, which is now far better understood and avoided by aviators. Fujita also lent his name to the "F Scale" he developed to measure the strength of tornadoes by analyzing the damage they cause on the ground.

Fujita was born in Kitakyushu City, Japan, to Tomojiro, a schoolteacher, and Yoshie (Kanesue) Fujita. Fujita showed an early aptitude for science and obtained the equivalent of a bachelor's degree in mechanical engineering from the Meji College of Technology in 1943. It was while he was working as an assistant professor of physics at Meji that U.S. forces dropped the atom bomb on the Japanese cities of Hiroshima and Nagasaki. Fujita visited the ruins three weeks after the bombings. By measuring the scorch marks on bamboo vases in a cemetery in Nagasaki, Fujita was able to show that only one bomb had been dropped. Surveying the damage in Hiroshima, Fujita calculated how high above the ground the bombs had exploded in order to create their unique starburst patterns, which would become important to his later work.

Leaving Meji College in 1949, Fujita became an assistant professor at Kyushu Institute of Technology while pursuing his Ph.D. in atmospheric science at Tokyo University. Like others involved in atmospheric science, he had read the published articles of Horace R. Byers of the University of Chicago, who had conducted groundbreaking research on thunderstorms in 1946 and 1947. Fujita translated two of his own articles on the same subject into English and sent them to Byers. Byers was impressed with Fujita's work and the two men began a correspondence. In 1953, the year Fujita received his doctorate, Byers extended an invitation to the Japanese scientist to work at the University of Chicago as a visiting research associate.

Fujita worked at the University as a senior meteorologist until 1962, when he became an associate professor. For two years beginning in 1961, he was the director of the Mesometeorological Research Project, and in 1964, Fujita became the director of the Satellite and Mesometeorology Research Project. Fujita was made a full professor in 1965, and held the Charles E. Merriam Distinguished Service Professorship on an active basis and on an emeritus basis. He became a naturalized U.S. citizen in 1968, and adopted the first name Theodore for use in the United States. He married Sumiko Yamamo in June, 1969, and has a son from his first marriage.

From the mid1960s, Fujita and his graduate students did extensive aerial surveys of tornadoes. Fujita claims to have logged over 40,000 miles flying in small planes under the worst of weather conditions. In the late 1960s, Fujita developed his tornado "F Scale." Traditionally, meteorologists listed only the total number of tornadoes that occurred, having no objective way to measure storm strength. Fujita constructed a system of measurement that correlates ground damage to windspeed. His six point system operates on an F0 to F5 scale and is similar to the Richter scale used to measure the strength of earthquakes.

Fujita did not actually witness a tornado until June 12, 1982, so the mainstay of his work was research on the aftermath of tornadoes. While at the National Center for Atmospheric Research in Denver, Colorado, Fujita spotted a tornado in the region early and collected some of the best data on the phenomenon ever.

In 1974, Fujita began analyzing the phenomenon of microbursts. Flying over the devastation wrought by a tornado, he noticed patterns of damage similar to those he had witnessed in Hiroshima and Nagasaki. "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," Fujita explained in The Weather Book: An Easy to Understand Guide to the U.S.A.'s Weather. Meteorologists knew by the mid1970s that severe storms produce downdrafts , but they assumed those downdrafts lost most of their force before they hit the ground and, therefore, did not cause much damage, so the phenomenon was largely ignored. Encouraged by Byers, Fujita coined the term "downburst" and began research to prove his thesis that downdraft is a significant weather phenomenon. Aided by the National Center for Atmospheric Research, he set up a project near Chicago that detected 52 downbursts in 42 days.

Fujita was eventually able to show that downdrafts cause so-called wind shear, a sudden and dramatic change in wind velocity, which causes damage on the ground and is a particular hazard in aviation, especially to planes taking off, landing, or flying low. Windspeeds up to F3 are common for downbursts (higher F Scale readings usually indicate tornadoes). Fujita has commented that a lot of damage attributed to tornadoes in the past has really been the work of downbursts. "After I pointed out the existence of downbursts, the number of tornadoes listed in the United States decreased for a number of years," Fujita noted in The Weather Book.

Fujita's research finally gained national attention in the 1980s. Wind shear caused by downdraft was cited as a contributing factor in the July 1982, crash of a Pan American 727 in New Orleans, Louisiana, which killed 154 people. During that event, the airliner was observed sinking back to the ground shortly after takeoffthe apparent result of wind shear. Another accident occurred in August 1985, when Delta Flight 191 crashed at Dallas-Ft. Worth Airport, killing 133 people. Again, wind shear was suspected to be the immediate cause of the catastrophe.

Air safety has improved dramatically because of Fujita's work, which led to the development of Doppler radar. Doppler radar is so sensitive it actually picks up particles of debris in the air that are as fine as dust. Movements of these particles are tracked to measure shifts in wind velocity. "This is particularly important in being able to detect the precursor events for severe weather," Frank Lepore, public affairs officer for the National Weather Service, told Joan Oleck in an interview. By 1996, the Weather Service and U.S. Air Force together installed 137 Doppler systems, essentially blanketing the continental United States. Harking back to the airline accidents of the 1980s, Lepore noted "a reduction in those incidents today because there is Doppler radar available. By being able to measure the internal velocity of air moving inside a storm system, [aviators] can see rising and falling volumes of air. They're now getting 20- and 25-minute warning on thesystems that cause tornadoes."

In 1988, Fujita assumed directorship of the Wind Research Lab at the University of Chicago. Among his many awards were the 1989 Medaille de Vermeil from the French National Academy of Air and Science for identifying microbursts; the 1990 Fujiwara Award Medal from the Meteorological Society of Japan for his research on mesometeorology; the 1991 Order of the Sacred Treasure, Gold and Silver Star from the Government of Japan for his tornado and microburst work; and the 1992 Transportation Cultural Award from the Japanese Government for his contributions to air safety. Fujita died in Chicago at the age of 78.

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