Anna Mani Pioneering Indian Female Scientist and Meteorologist

Her father, Modayil Pothen Mani, was the first Indian engineer in the Travancore Public Works Department. Her mother, Ammamma, raised five boys and three girls. The family held cardamom estates in the hills around Peermade.

She had wanted to study medicine but chose physics because it was her best subject. She studied at Women’s Christian College and then Presidency College. At college she read socialist literature and kept left-leaning company, though she never joined a party. After graduating she spent a year as a demonstrator at Women’s Christian College.

She worked on the spectroscopy of diamonds and rubies. Raman’s laboratory held about 300 diamonds from India and Africa, and she recorded the spectra of 32 of them, with exposures of 15 to 20 hours on photographic plates, often through the night. She was one of three women in the laboratory and published single-author papers from 1942. In 1945 the University of Madras refused her a PhD because she did not have an MSc.

It was the only placement open to her. Her training included meteorological stations in England and Scotland, and three months at the National Physical Laboratory in Teddington learning about standards. Her PhD dissertation, completed but never awarded, is held in the library of the Raman Research Institute.

She started by installing instruments imported from Britain. Mentored by S. P. Venkiteshwaran, she became head of the Surface Instruments division, and by 1953 she was leading 121 men.

Her first was a recording rain gauge, followed by instruments for humidity, temperature, pressure and wind. She prepared drawings, specifications and manuals for about a hundred instruments, and the workshops in Pune and New Delhi built them. Calibration that once meant sending instruments to Davos could increasingly be done in India.

Radiosondes from around the world were flown side by side to test their accuracy.

K. R. Ramanathan encouraged the work. The first four stations opened in 1957 with European instruments, while she and Oommen Chacko built Indian ones at Pune: a pyrheliometer for direct sunlight, then a pyranometer and a pyrgeometer. She trained the field staff and insisted on consistent calibration so readings from different stations could be compared.

She brought new manufacturing methods back to the department’s workshops.

She chaired the radiation working group of the WMO Commission for Instruments and Methods of Observation, and the radiation group for its Asian region. Pune became a regional radiation centre and a training centre for radiation measurement.

Development started in 1962, and the first successful flight was in September 1964. The balloon-borne instrument measures ozone at different heights, and regular flights followed at Pune, New Delhi and Thiruvananthapuram.

She was technical director of the pyrheliometer comparisons at Davos in 1964 and 1969, and coordinated sunshine-recorder comparisons across 58 countries from 1964 to 1968, as well as pyranometer comparisons at Pune, Vienna and St Petersburg.

She sat on the advisory working group of the WMO Commission for Instruments and Methods of Observation and on its groups for atmospheric electricity, precipitation and radiation, and helped revise the WMO Guide to Instruments and Methods of Observation. In 1970 she sent her colleague Oommen Chacko with Pune’s standard pyrheliometer to Tokyo, Seoul, Hong Kong, Saigon, Bangkok and Colombo, so each could calibrate against it without paying for the trip.

By then the solar radiation network had grown to 24 stations, against the 14 first planned. She was a WMO consultant in Egypt in 1975 and retired in 1976.

India then doubled its ozone soundings, building a record of ozone over the tropics.

She helped the team setting up millimetre-wave telescopes at the institute and at Nandi Hills by measuring the water vapour above each site: 5 to 6 mm over Nandi Hills, against 35 to 40 mm over Bangalore. She later ran the Indian Institute of Tropical Meteorology’s field station at Peenya and set up a workshop making wind and solar instruments.

Handbook of Solar Radiation Data for India (1980) covered 18 stations, and Solar Radiation over India (1981) gave computed data for 145. The Ministry of New and Renewable Energy still uses the handbook for solar projects.

She was a Fellow of the Academy and of the Indian National Science Academy, served on the Academy’s Council and as its Secretary, and chaired the association that publishes Current Science.

Her team chose automated instruments, put up 20-metre masts and coordinated surveys across states, starting with 21 stations in 1984 and reaching about 150 by 1996. The results were published in four volumes of Wind Energy Resource Survey in India.

She spent her last years in Kerala, cared for by her elder sister Chellamma Chandy and her family.