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Howard Latimer

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Howard Latimer Penman, a British meteorologist, is widely known in hydrology, meteorology and environmental physics as the author of an equation for estimating the rate at which a surface freely supplied with moisture is likely to lose water by evaporation (the Penman equation).

Penman was born in County Durham in 1909 and studied at Durham University where he graduated in Physics in 1930 and taught for some time at a boys school before returning to Armstrong College (Durham University).

In 1937 Penman applied for a post in the Soil Physics Department at Rothamsted Research, becoming departmental head in 1954. After analyzing data from drainage and rain gauges that had been operating at Rothamsted since 1870, Penman became interested in the rate at which crops lose water by evaporation. Some of his major contributions would follow from these beginnings.

Penman's classical paper "Natural evaporation from open water, bare soil and grass" (Proceedings of the Royal Society, 1948) showed how the partitioning of available energy was related to windspeed and saturation deficit, and included the unique analysis that enabled surface temperature to be eliminated from the relevant equations. The paper has been widely quoted in the literature of agricultural meteorology and hydrology.

Penman also wrote seminal papers on diffusion of gases in porous media. In 1961, he served as President of the Royal Meteorological Society, and in 1965, he was elected a Fellow of the Royal Society. He served on many academic and government bodies, and travelled widely, advising on reservoir projects and water needs, and was awarded the Order of the British Empire. He retired from Rothamsted in 1974, but continued to take an interest in scientific and international issues until his death in 1984.

In 1986, a list of his 104 papers and reports was published in the Biographical Memoirs of the Royal Society.

This contribution was written by Luiza Borba based on the available online literature.