Today In Science History – November 19 – Fujita Scale for Tornadoes   Recently updated !

Tetsuya Theodore "Ted" Fujita
Tetsuya Theodore “Ted” Fujita (1920 -1998)
University of Chicago

November 19 marks the passing of Tetsuya “Ted” Fujita. Fujita was a Japanese-American meteorologist who studied severe storm systems. He is best known for the tornado rating system he developed, the Fujita scale.

The Fujita scale was developed in 1970 as an attempt to rate the severity of tornados based on the wind speed the tornado produces.

F-ratingWind Speed (MPH)Damage
F00 – 73Light Damage: Branches knocked off trees, signs damaged, some trees pushed over
F173-112Moderate Damage: Roof shingles removed, mobile homes pushed off foundations, moving cars blown off roads
F2113 – 157Considerable Damage: Roofs torn off houses, mobile homes destroyed, boxcars pushed over, large trees uprooted, light objects become missiles, cars lifted off the ground
F3158 – 206Severe Damage: Roofs and walls destroyed on well-built homes, trains overturned, most trees uprooted, large cars lifted off the ground
F4207 – 260Devistating Damage: Well-built homes destroyed, mobile homes blown some distance, large objects become missiles
F5261 – 318Incredible Damage: Strong frame buildings leveled and removed from foundations, car-sized missiles thrown in excess of 100 meters

The National Weather Service adopted this scale and began to apply it to historical tornados in their database. The subjective nature of the damage scale caused a few problems. High windspeed tornados could be over quickly and cause little more damage than blowing some limbs off trees. Slow moving low windspeed storms could cause extensive damage to mobile home parks. The Enhanced-Fujita scale was designed to address a few of these issues in 2007. The Enhanced F-scale (EF-scale) has different wind-speed ranges from the original Fujita scale, but the damages are similar. EF storm ratings include damage indicator codes to reflect the buildings damaged.

Fujita is also known for the discovery of microbursts. Microbursts occur on the edges of large thunderstorms where a large mass of air suddenly drops to the ground level. Microbursts can generate wind speeds in excess of 170 miles per hour (270 km/hr).

There are two types of microbursts: wet and dry. A wet microburst is usually accompanied by significant rainfall where the rainfall pulls the air as the drops fall. Hail and ice melting tends to increase the likelihood of a wet microburst forming. A dry microburst is formed when the ground is significantly warmer than the storm above it. As the rain falls, it meets the hot air above the ground and evaporates the rain and cools the air. The resulting cold air falls to the ground and the lower pressure pulls more air down from the storm.

Once the microburst hits the ground, the air is forced away in all directions and curls up and back towards the downdraft. This localized activity is particularly dangerous to aircraft flying through a microburst. They have been known to cause fatal crashes of large jet airliners and several small aircraft.

Fujita’s studies in severe storms earned him the nickname “Mr. Tornado” from the media and his associates.

Notable Science History Events for November 19

2013 – Frederick Sanger died.

Sanger was an English biochemist who has the distinction of being one of the four people to have won two Nobel Prizes. He is also one of two that won the Prize in the same category each time.

Sanger’s first Prize was for his work involving proteins and their structures. He was working with bovine insulin when he discovered the amino acid sequence that makes up the chemical structure of Bovine insulin A and B. This discovery proved proteins have a set chemical composition and every protein has a definite and unique amino acid sequence. This would earn him the 1958 Nobel Prize in Chemistry.

His second Prize would also be for amino acid research. This time his team developed new methods to sequence RNA molecules. They would separate the RNA molecule into fragments and cause different reactions to highlight which amino acids made up the fragments. Eventually, they managed to successfully sequence the 5S ribosomal RNA of Escherichia coli bacteria. Once they were confident in their technique, they moved on to sequencing DNA molecules. This new technique would earn him the 1980 Nobel Prize in Chemistry. This technique would be the basic tools for biochemists to eventually unlock the human genome.

Sanger managed to spend his entire scientific career in research. He never held a teaching position. He admitted he had little aptitude for administration or teaching and preferred to do work himself rather than assigning it to junior scientists. He disliked trying to come up with experiments for others to run.

2004 – John Robert Vane died.

John Robert Vane
John Robert Vane (1927 – 2004)
Wellcome Foundation

Vane was a British biochemist who spent his career studying prostaglandins. Prostaglandins are compounds that regulate many different functions in the body. Vane developed a test called the dynamic bioassay that identified and measured the substances that make up blood and other fluids of the body. Using this test, he discovered prostaglandins are produced by several tissues and organs and their effect was short ranged, typically affecting the area near where they were produced. One of the experiments he performed found that aspirin inhibited the production of prostaglandin that causes inflammation. This demonstrated definite physiological evidence to support the use of aspirin as an anti-inflammatory medicine. This discovery would also earn him a third of the 1983 Nobel Prize in Medicine.

He also discovered another prostaglandin called prostacyclin that was important to the process of blood coagulation. Prostacyclin is used to prevent blood clotting during surgeries and also to dissolve blood clots that may cause heart attacks and strokes.

1998 – Tetsuya Theodore “Ted” Fujita died.

1990 – Georgii Nikolaevich Flerov died.

Flerov was the Russian physicist who recognized the spontaneous fission of uranium. He set up several research centers into nuclear science and was a direct influence on nearly every Russian nuclear scientist. One laboratory he set up was the Dubna laboratory which synthesized many transactinide elements. Element 114 was named Flerovium in his honor.

1936 – Yuan Tseh Lee was born.

Yuan T. Lee
Yuan T. Lee
Lawrence Berkeley National Laboratory

Lee is a Taiwanese-American chemist who shares the 1986 Nobel Prize in Chemistry with John Polanyi and Dudley Herschbach for their contributions to the understanding of elementary chemical processes. Lee worked with Herschbach’s crossed molecular beam technique where beams of molecules are accelerated and forced to collide to study the events that occur during reactions in the collisions. He added the ability to conduct mass spectrometry to identify the products of oxygen and fluorine beams crossed with organic compounds.

1915 – Earl W. Sutherland, Jr. was born.

Sutherland was an American biochemist who was awarded the 1971 Nobel Prize in Medicine for his discovery of how hormones work. He isolated cyclic adenosine monophosphate (cyclic AMP) and discovered how it acts as a second messenger in cells. He also demonstrated its role in the actions of hormones on the cellular level.

1912 – George Emil Palade was born.

Palade was a Romanian cytologist who shares the 1974 Nobel Prize in Medicine with Albert Claude and Christian de Duve for their discoveries in cell function and organization. The discovered the vacuole that is present in all plant cells and some animal and bacteria cells. They are enclosed compartments in the cell membrane that contain enzymes in solution that maintain cell health and conditions.

1887 – James Batcheller Sumner was born.

James Batcheller Sumner
James Batcheller Sumner (1887 – 1955)
Nobel Foundation

Sumner was an American chemist who was awarded half the 1946 Nobel Prize in Chemistry for the discovery that enzymes could be crystallized. He discovered enzymes could be isolated in a pure form by isolating urease. He also showed urease was a protein and proved enzymes were proteins.

1872 – David Cowie was born.

Cowie was a medical researcher who was instrumental to the addition of iodine in table salt in the United States. Cowie was aware of a Swiss process of adding sodium iodide to table salt (sodium chloride). He convinced Michigan salt producers to include minute quantities of sodium iodide to their salt for consumption locally. This type of salt was identified by the label “contains .01 percent sodium iodide”. In less than a year, the Morton Salt Company was distributing iodized salt nationally.

1672 – Franciscus Sylvius died.

Franciscus Sylvius
Franciscus Sylvius (1614 – 1672)

Sylvius was a Dutch physician and educator. He established the Sylvius Laboratory in Leiden University that was the first academic chemical laboratory. He also established the Iatrochemical School of Medicine. It was the first medical school founded on the principles of chemistry and physics instead of the metaphysical humors, phlegm, and bile.