Sir John Mason: Physicist who modernised the Meteorological Office and made it an internationally-admired institution

Mason solved a problem which had bewildered scientists since Benjamin Franklin’s time – how do thunder clouds generate electrical charges?

On 11 May 1965 Sir Graham Sutton, Director General of the Meteorological Office since 1953, was guest speaker at a meeting of the Parliamentary and Scientific Committee. He brought with him “my young colleague, a gifted meteorologist, John Mason, who will most certainly steer the Met Office towards new levels of scientific excellence.” For the next 18 years Mason did just that.

When Mason spoke – he had just been elected as a Fellow of the Royal Society – we sensed that here was a heavyweight and determined operator. This was confirmed in 1973 when the P&S Committee went on a visit to the Met Office at Bracknell. Over lunch it became clear that the long-serving members of the Met were deeply impressed by their new Chief’s drive, initiative and sheer scientific and technical excellence. Mason was indeed a respected leader of discerning and gifted scientific colleagues.

Basil John Mason was the son of John Robert and Olive Mason in the Norfolk village of Docking. At Fakenham Grammar School he deemed himself lucky to be superbly taught in maths and science. When I asked him what sparked his interest in physics, he replied, “A combination of particular teachers who aroused in me a sense of curiosity – and those wonderful skies and cloud formations that you find in North Norfolk.” This launched him on a lifelong career devoted to the planet’s weather.

After a brief spell at University College, Nottingham, he was called up to the RAF in 1941, his obvious talents put to good use as a chief instructor. In 1943 he was promoted to a staff officer in telecommunications, focusing on radar. Demobbed, he returned to Nottingham and obtained a first class degree in pure maths and physics. From Nottingham he went to London University, which in 1956 awarded him a DSc. There followed academic posts at Nottingham and the Department of Meteorology at Imperial College.

In 1959, he told us with a chuckle that looking for more settled weather, the Masons made a temporary home in the US when he was Visiting Professor of Meteorology at the University of California. He told us that missing his home climate he then returned to Imperial as Professor of Cloud Physics. His book The Physics of Clouds was published in 1957 (with a second edition in 1971).

As his Laureator, Professor Philip Harper of Heriot-Watt University, put it in 1991 when bestowing an honorary degree on him, “Organisation of the actual weather proved difficult, even for Sir John, but doing the next best thing he joined whole-heartedly in the organisation of its study, notably by directing the research of the World Meteorological Office.”

Mason was active in promoting the British Association for the Advancement of Science, as Honorary General Secretary and later President, and was a pivotal member of the Astronomy Space Radio Board of the Science and Engineering Research Council.

Mason never hesitated to share his scientific opinions. I was told by Quintin Hailsham, the Minister for Science who had endorsed Mason’s succession to Sir Graham Sutton as Director-General of the Met Office, that Mason used his considerable stature to pin Margaret Thatcher, in her Prime Ministerial heyday, into a corner, the better to inform her about the upper atmosphere.

At Imperial Mason had formed a research group to study the fundamental processes that influence cloud formation, and how snow, hail and rain are formed. His important book, Clouds, Rain and Rain-making, was published in 1962. The second edition (1975) showed that after 10 years of running the Met Office he was still at the cutting edge of research.

Mason solved a problem which had bewildered scientists since Benjamin Franklin’s time – how do thunder clouds generate electrical charges? He was able to show how precipitation within a cloud in the form of hail pellets, or ice crystals, colliding millions of times per second, is sufficient to cause a charge, triggering lightning. He also presented an equation to describe the growth, through evaporation or condensation, of a water droplet within a cloud. This has passed into scientific annals as the Mason Equation.

Mason came to be highly regarded by the international scientific community. He told the story of how, as a speaker at a conference in Moscow, he was provided with a personal guide, who led him through the Spassky Gate into the Kremlin. “Through this gate,” the guide began, “came Napoleon. A little later came Lenin. And now, John Mason.”

He held many honorary degrees and was awarded the Charles Chree Medal and Prize of the Physical Society (1965), the Rumford Medal of the Royal Society (1972) and the Glazebrook Medal of the Institute of Physics (1974).

Retiring from the Met Office in 1983, he became chairman of the Co-ordinating Committee on Marine Science and Technology, charged with producing a national strategy in this area. At 69 he published a significant book, Acid Rain, while directing the Anglo-Scandinavian research programme for six years. I know that friends of mine who walk and climb in the Scottish mountains can thank Mason for his crucial support in setting up the Scottish Weather telephone service.

He told me the highlight of his career was being an active Chancellor of the University of Manchester Institute of Science and Technology. One of Umist’s former Vice Chancellors, Lord Bowden, was incredulous. “Mason is simply the most highly organised man in Britain,” he said. “How on Earth does he manage to write three major, pioneering, scientifically complex books, contribute more than 250 articles to physics and meteorological journals, run the Met Office and raise two gifted sons [Barry Michael, a senior civil servant in the Department of the Environment, and Nigel John, Professor of Molecular Physics in the Open University]?” I suspect the answer is energy of thunderous proportions combined with wonderful support from Doreen, his wife of two-thirds of a century.

In 1973 six schoolchildren perished in deteriorating weather conditions on Cairngorm. Professor Des Smith FRS, head of physics at Heriot Watt university, alerted his friend, Mason. Smith told me, “Mason reacted promptly and we set up the first mountain weather service and avalanche warning system in Scotland.” Mason was a man of action.

John Mason, physicist: born Docking, Norfolk 18 August 1923; CB 1973, Kt 1979; married 1948 Doreen Sheila Jones (two sons); died London 6 January 2015.