Dobson, Gordon Miller Bourne
Dobson, Gordon Miller Bourne (1889–1976), physicist and meteorologist, was born at Knott End, Windermere, on 25 February 1889, the youngest child in the family of two sons and two daughters of Thomas Dobson, a general practitioner in Windermere, and his wife, Marianne Bourne. He was educated at Sedbergh School and entered Gonville and Caius College, Cambridge, in 1907, obtaining a first class in part one of the natural sciences tripos in 1910.
From an early age Dobson showed an interest in practical things. When a young boy he set up a field telephone between the house and the stable, and at school spent much of his spare time in the physics laboratory. While an undergraduate he devised a simple apparatus he set up at his father's boathouse for recording the seiches on Windermere. The results were published in Nature in 1911. Following this work Dobson came to the notice of W. Napier Shaw, director of the Meteorological Office, who offered him a post at Kew observatory under Charles Chree. In 1913 Dobson was appointed meteorological adviser to the newly formed Military Flying School on Salisbury Plain where, using pilot balloons, he made the first measurements of the variation of wind with height. In 1914 Dobson married Winifred Duncome Rimer (d. 1952), the sister of one of his friends at Sedbergh School and the daughter of Henry Rimer, a solicitor. Their three children were a daughter and two sons.
In 1916 Dobson was appointed director of the experimental department at the Royal Aircraft Establishment, Farnborough, and he worked closely with F. A. Lindemann. After the war Lindemann moved to Oxford as Dr Lee's professor of experimental philosophy. Dobson followed him in 1920 as university lecturer in meteorology at the Clarendon Laboratory. With Lindemann he immediately began research on meteors. Lindemann concentrated on the theory of their burn-up in the upper atmosphere; Dobson analysed the observations. In 1922 they published in the Proceedings of the Royal Society a paper clearly demonstrating the presence of a warm layer at a height of about 50 km in contrast to the expected result of a steady fall of temperature with height throughout the atmosphere. Dobson was made DSc of Oxford in 1924.
Realizing that the source of heating for the warm layer was likely to be the absorption of ultraviolet radiation by ozone, Dobson embarked on the study of atmospheric ozone, a subject which he pursued with unrelenting vigour for the rest of his life. Ozone measurements were made by means of ultraviolet solar spectroscopy. In building his spectrograph, a task which he carried out personally in the laboratory of his home on Boars Hill near Oxford, Dobson showed a great deal of ingenuity and practical skill. For the measurement of the photographic plates he built the first photoelectric microphotometer using a potassium photocell, the current from which was measured by a Lindemann–Keeley electrometer; both photocell and electrometer were made in the Clarendon Laboratory, and the new techniques were published in 1926.
During 1925 and 1926 five spectrographs were built and deployed at various locations in Europe, the photographic plates being returned to Oxford for measurement. More extensive measurements of atmospheric ozone were organized during 1928 and 1929 by redistributing the instruments to locations widely scattered over the world including one as far afield as Christchurch, New Zealand. By 1929 Dobson had established the main features of the variations of total ozone with synoptic conditions and with latitude and season. In 1927 his work was recognized by his election to a new university readership in meteorology, to a fellowship at Merton College, and to fellowship of the Royal Society.
Dobson continued with instrument development. He designed and built, about 1927 or 1928, a photoelectric spectrophotometer which enabled the relative intensity at two wavelengths and hence the ozone amount to be measured directly. Remarkably advanced for its day, this became the standard instrument for measuring atmospheric ozone and its basic design was little changed for many decades. For the International Geophysical Year in 1956, 144 were distributed throughout the world, the organization and much of the calibration of the instruments still being carried out from Dobson's home in Oxford.
In the 1930s Dobson became concerned with the study of atmospheric pollution. From 1934 to 1950 he served as chairman of the atmospheric pollution committee of the Department of Scientific and Industrial Research. Under his guidance reliable methods were developed for the measurement of smoke, deposited matter, and sulphur dioxide.
During the Second World War, Dobson became involved with the Meteorological Office in the forecasting of conditions under which aircraft form condensation trails. This led him to a further piece of ingenious instrument design, the Dobson–Brewer hygrometer for measuring the very low humidities found in the stratosphere. The first water vapour measurements in the stratosphere together with a summary of the ozone work were described in the Bakerian lecture of the Royal Society which Dobson gave in 1945. To explain the results from these measurements together with the seasonal and latitudinal variations of ozone, a simple arrangement of the mean motions of air in the stratosphere was proposed which became known as the Dobson–Brewer circulation. In 1942 Dobson was awarded the Royal Society Rumford medal and in 1945 Oxford University conferred on him the title of professor. In 1947–9 he was president of the Royal Meteorological Society. In 1951 he was appointed CBE. He retired from his readership in 1950 and from his demonstratorship in 1956.
Dobson's wife died in 1952 and in 1954 he married Olive Mary Bacon, who survived him. She was the daughter of Ernest Arthur Bacon, assistant registrar for the diocese of Oxford. In 1937 Dobson had moved his home and private laboratory to Shotover on the east side of Oxford where 10 acres of ground allowed him to pursue his interests in farming, especially in fruit growing. He was a keenly religious man, being a churchwarden at St Aldates Church, Oxford, for many years. Throughout his retirement years Dobson continued with work on ozone, helping considerably with its international organization through the International Ozone Commission. Observations were made from Shotover Hill on all possible occasions, the last being made on 30 January 1976, the day before he had the stroke from which he died on 10 March 1976 at Thames Bank Nursing Home, Goring, Oxfordshire.
- C. D. Walshaw, ‘G. M. B. Dobson: the man and his work’, Planetary and Space Science, 37/12 (1989), 1485–507
- J. T. Houghton and C. D. Walshaw, Memoirs FRS, 23 (1977), 41–57
- d. cert.
- personal knowledge (1986)
- private information (1986)
- Bodl. Oxf.
- Sci. Mus., ozonometers, other apparatus
- photograph, repro. in Houghton and Walshaw, Memoirs FRS
Wealth at Death
£72,384: probate, 30 July 1976, CGPLA Eng. & Wales