How Ted Fujita Revolutionized Tornado Science and Made Flying Safer Despite Many Not Believing Him – The Weather Channel

Ted Fujita examines the circulation produced by a tornado vortex generator in his lab at the University of Chicago.

When people challenge a long-held belief, there is often pushback, and the famed weather researcher Dr. Tetsuya Theodore Ted Fujita was no exception. In his landmark studies of thunderstorms and tornadoes, Fujita made more than one discovery that his peers just couldnt acceptuntil they did.

Fujita, who carried out most of his research while a professor at the University of Chicago, will be profiled on Tuesday in Mr. Tornado, an installment of the PBS series American Experience.

Fujita is best known for the scale he created with meteorologist Allen Pearson to estimate tornado winds by the level of destruction found. Introduced in 1971, and updated as the Enhanced Fujita Scale in 2007, the scale (also known simply as the F-scale, running from EF0 to EF5) is the near-universally accepted yardstick for gauging tornado strength.

Fujita was delighted when the National Weather Service adopted the original Fujita-Pearson Scale in the 1970s. He wasnt so thrilled when people refused to accept the concept of suction vortices. These mini-whirls spin around the edge of a multiple-vortex tornado, completing a circuit in mere seconds and adding as much as 100 mph to the parent tornados top winds.

A multi-vortex tornado developing near Katie, Oklahoma, on May 9, 2016.

Countless photos and videos have confirmed the existence of suction vortices, which produce some of the worst tornado damage as well as its often-haphazard-seeming nature.

Such images werent available in 1970, when Fujita first came up with the concept after analyzing damage from a tornado in Lubbock, Texas. His colleagues literally couldnt see it.

I got into a tremendous argument, Fujita recalled in a 1988 oral history conducted by the American Meteorological Society (AMS) and the National Center for Atmospheric Research. You talk about a tornado; people take lots of pictures of a nice tornado [which has] one funnel. How can I say there's a small vortex running around, dancing around?

[They] said: You're dead wrong. But I still pursued my concept.

What turned the tables was a catastrophe: the Super Outbreak on April 3, 1974, which produced 148 twisters across the eastern U.S. and killed more than 300 people. The only comparable event in modern U.S. history is the Super Outbreak of April 27, 2011, that ravaged the South.

Fujita carried out aerial and ground surveys of the extensive damage, and they made the existence of suction vortices crystal clear.

Indianapolis TV stations sent me a beautiful [movie] that showed my suction vortices dancing around, and I went to the spot to find exactly what I expected. One house was damaged; the one right next to it was standing, untouched. Houses located in between the path of suction vortices left standing confirmed everything.

Fujita's aerial surveys in 1974 helped spur another of his great contributions: the discovery of microbursts. These compact, intense downdrafts led to the deaths of hundreds of air passengers in catastrophic wrecks, until a warning system was developed and implemented in the 1990s.

Since 1994, not a single U.S. airline passenger has been killed by a microburst.

In this 1980s photo, rain-cooled air from a thunderstorm crashes to the ground in the form of a downburst near Denvers former Stapleton International Airport, one of the main sites where microburst warning systems were developed and tested.

As a 24-year-old assistant university professor in Japan during World War II, Fujita visited Nagasaki and Hiroshima just weeks after nuclear bombs dropped by the U.S. devastated both cities. He mapped out how the catastrophic damage radiated from a central point, and theorized that thunderstorms must have similar downdrafts.

A landmark U.S. study in the 1940s and 1950s called the Thunderstorm Project independently came up with the same conclusion. But the dynamics behind these downdrafts didnt seem to be intense enough to cause major damage.

Fujita returned to the downdraft concept after he noticed starburst-like damage patterns from the 1974 Super Outbreak. These differed dramatically from the cyclonic swirls typical of tornado damage.

On June 24, 1975, an Eastern Airlines flight crashed in a thunderstorm at John F. Kennedy International Airport in New York, killing 113 of the 124 people aboard. Fujita was asked to investigate the accident. I analyzed about an eighteen-minute period when there were more than ten aircraft around [the apparent weather feature]. Some reported very bad wind shear, but the next one didn't. Even the control tower was confused.

Harking back to his first hand look at nuclear bomb damage, Fujita concluded that a much smaller, more intense downdraft must have been at work.

I got quite a bit of resistance at the time, but I'm glad that I went through it, Fujita said. What rescued me at the time were the pilots.They said, We had the same experience. It looked very innocuous and we went through it and all of a sudden, it was not a downdraft, there was a loss of airspeed.

Fujita surmisedand later studies confirmedthat the loss of airspeed occurred as pilots encountered a headwind, sinking air, and tailwind in rapid succession while flying through a microburst.

Among Fujitas other key insights:

He coined the terms collar cloud, tail cloud, and wall cloud in a paper analyzing a 1957 tornado that devastated Fargo, North Dakota. Storm spotters and chasers still use these terms often.

He introduced the concept of tornado families, in which a long-lived supercell thunderstorm produces several tornadoes in sequence. Storm surveyors now watch for distinct breaks between damage paths in order to distinguish members of a tornado family.

Greg Forbes, the longtime severe weather expert with The Weather Channel, was among those who earned a doctoral degree with Fujita as his advisor. Another was Roger Wakimoto, an eminent tornado researcher and former AMS president who is now vice chancellor for research at the University of California, Los Angeles.

I consider my time spent with Ted the personal highlight of my professional career, Wakimoto said in an email. I started at the University of Chicago unsure of my abilities to succeed. I left with a wealth of knowledge and confidence that I could successfully embark on a teaching and research career."

Fujita was a demanding advisor, but his enthusiasm, deep insights, and ability to conceptualize mesoscale processes were truly inspiring," Wakimoto added. "Ted loved to argue with other researchers when there was pushback for his suction vortex model, the existence of microbursts, and the accuracy of his windspeed estimates based on the F-scale. Debates on these topics seem to energize him, and he often said that time would prove that his theories were correct."

I was always in awe that his seminars and other public events would be literally packed to the rafters. He was a brilliant speaker and one of the greatest spokespersons for our community. I often think that today's TED talks were appropriately named after him.

Fujitas research continues to influence and inspire scientists delving into severe weather.

As a tornado nerd growing up in Minnesota in the 1980s, Fujita was a supernatural figure, said Robin Tanamachi, an assistant professor at Purdue University. Though Tanamachi never met him, I consider myself an heir of his scientific legacy. No matter which line of scientific inquiry I make in my tornado research, I always seem to come back to Fujita's books and papers.

While based at the University of Oklahoma, Tanamachi carried out measurements with a University of Massachusetts mobile Doppler radar of the very first tornado rated EF5 on the Enhanced Fujita Scalethe one that decimated Greensburg, Kansas, on May 4. 2007. She marvels at Fujitas exhaustive work in developing the original version of the scale.

Even today with mobile Doppler radars, accurate wind measurements in tornadoes are exceedingly rare, said Tanamachi. Fujita recognized that the only consistently available indicator of a tornado's wind speed is the damage path that it leaves behind.

By studying hundreds of tornado damage tracks, he was able to correlate damage to a standard indicator (a well-built house) to wind speeds, thereby creating the Fujita scale that is the basis for the Enhanced Fujita scale that we use today. All of this research was done without the aid of Doppler radars, drones, or machine learning.

This three-dimensional illustration of a microburst by Roger Wakimoto is based on a figure produced by Ted Fujita in 1985.

Tanamachi also points to Fujitas exceptionally meticulous illustrations, which became legendary in meteorological circles.

I was struck, as a child first learning about Fujita's work, by how even I could understand many of his graphics. They were simultaneously highly complex and yet crystal clear in their content and messaging.practically works of art, even more so because each image or frame of animation was painstakingly drafted by Fujita's own hand."

As a junior scientist, the lesson I took is that one can almost never spend too much time perfecting a figure," Tanamachi said. "It will be remembered long after the accompanying, explanatory text is forgotten.

Fujitas best-known legacythe tornado intensity scalehas continued to evolve long after Fujitas death in 1998 at age 78. Interest in an upgrade to the original F-scale grew as it became increasingly clear that peak tornado winds were likely lower than originally thought and that construction quality has a huge impact on tornado damage.

Following the April 26-28, 2011, tornado outbreak in the southeastern United States, James LaDue and Kevin Scharfenberg (NOAA/NWS) provided on-the-ground reports which, combined with information from aerial reconnaissance and emergency manager reports, led to an EF4 rating for the tornado affecting this location.

The Enhanced Fujita Scale that debuted in 2007 includes 28 separate damage indicators, ranging from single-family homes, manufactured homes, motels, and malls to transmission lines and hardwood trees. Each indicator has its own mini-scale that feeds into the tornados overall EF-scale rating. (The scale is calibrated so that a tornado with a given F rating in the old scale is comparable to the same EF rating in the new scale, even though estimated winds are now lower.)

Now theres another major upgrade in the works. James LaDue (NWS Warning Decision Training Division) is co-chairing a committee with the American Society of Civil Engineers that is charged with incorporating other types of data into the EF-rating process. For example, this could include observations from mobile radars, which can estimate peak winds in places where no visible damage occurred.

Ted had an amazing curiosity to investigate everything, said LaDue. He noted that when Fujitas health began to decline in the late 1990s, he applied his usual observational rigor and graphic skills to documenting his own health indicators, an account that was published in his memoirs.

Ted Fujita's publications still set the standard which we can only improve upon but never replace, LaDue said.

The Weather Companys primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

Read this article:
How Ted Fujita Revolutionized Tornado Science and Made Flying Safer Despite Many Not Believing Him - The Weather Channel