The model scientist who fixed the greenhouse effect

Syukuro ("Suki") Manabe in the 1960s at Princeton University, New Jersey, where he taught from 1968-1997. He was working on weather prediction in Tokyo during the difficult postwar years when he was invited to come to the US Weather Bureau's unit working on the general circulation of the atmosphere. He was assigned programmers to write computer code so he could concentrate on the physical concepts and mathematics. Image copyright: AIP Emilio Segrè Visual Archives, used with permission.

Syukuro (“Suki”) Manabe in the 1960s at Princeton University, New Jersey, where he taught from 1968-1997. He was working on weather prediction in Tokyo during the difficult postwar years when he was invited to come to the US Weather Bureau’s unit working on the general circulation of the atmosphere. He was assigned programmers to write computer code so he could concentrate on the physical concepts and mathematics. Image copyright: AIP Emilio Segrè Visual Archives, used with permission.

In 1963, using one of the world’s first transistor-based supercomputers, Syukuro Manabe was supposed to be simulating how Earth’s atmosphere behaves in more detail than ever before. Instead, the young US Weather Bureau scientist felt the frustration, far more common today, of a crashed system. But resolving that problem would lead ‘Suki’ Manabe to produce the first computerised greenhouse effect simulations, and lay the foundations for some of today’s most widely used climate models.

After growing up during the Second World War, studying in bomb shelters, Suki entered the University of Tokyo in 1949 to become a doctor like his father and grandfather. The same year Japanese physicist Hideki Yukawa won a Nobel Prize, and helped drive many students into his subject, including Suki. “I gradually realized, ‘Oh my God, I despise biology,’” he told interviewer Paul Edwards in 1998. But to start with, he wasn’t very successful in his new subject. “At the beginning my physics grade was miserable – straight C,” he recalled.

Those grades came about because Suki’s main interest was in the mathematical parts of the subjects, but he hadn’t been thinking about what the maths really meant. When he realised this he concentrated on the physics he found most interesting, in subjects related to the atmosphere and oceans, and his grades started to improve. “By the time I graduated from geophysics and went on to a Master’s course at the University of Tokyo, I was getting a pretty solid way of thinking about the issues,” he said.

Suki went on to get a PhD, but when he finished the kinds of jobs in meteorology he was qualified for were hard to find in Japan. But he had applied his interests to rainfall, in an approach known as numerical weather prediction pioneered by scientists like John von Neumann, Carl-Gustaf Rossby and Bert Bolin. Another leader in the field, Joe Smagorinsky, was looking at rainfall in a similar way, and had read Suki’s research. Joe was setting up a numerical weather prediction team at the US Weather Bureau in Washington, DC, and in 1958 invited Suki to join him.

Their early models split the world into grids reaching into the air and across its surface, calculating what happens within and between each cube as today’s versions still do. But Joe wanted Suki to go further in preparation for the arrival of a transistorised IBM ‘Stretch’ computer in 1963. Joe wanted to develop complex system models that included the role of water movements, the structure of the atmosphere, and heat from the Sun. In particular Joe wanted to push from simulating two layers in the atmosphere to nine. Read the rest of this entry »

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