Meteorology in Ancient India.  Mrs. A.A. Shiralkar and Dr. (Mrs.) P.S. Salvekar  Indian lnstitute of Tropical Meteorology, Pune.

Meteorology is the science of atmosphere which mainly includes phenomena such as wind and rain. As with any science it is difficult to determine the exact begining of Meteorology. However, notable evidence indicates that Meteorology, as a science, is comparatively young, while as a branch of knowledge, it dates back to tho origins of human civilization. There are three major periods in the history of Indian Meteorology. The first one is 600 B.C. to 1600 A.D. the period of speculation. The second period is 1600 A.D. to 1800 A.D. the dawn of scientific meteorology. The third major period begins in 1800 A.D. which is marked by the growth and refinement of modern theory. In India, Meteorology has its trace in Vedic age. Meteorological description are seen in the Rig Veda, about 5000 years ago. Of course, mythology was the essence of knowledge of those times and natural phenomena were considered as the attributes of Gods and heroes.  The five principal elements involved in Meteorology viz., Earth, Water, Radiation, Wind and Sky are nothing but the 'Panchtatwas' of that time named as Prithvi,Aap, Tej, Vaju, Aakash. These elements were treated as deities under the names of Varuna, Marut, Parjanya, indra ete. The ancient epics of the Hindus-Ramayana and Mahabharata mentions about the meteorology weapons, like `Varunastra' the weapon of rain to quench ` Agnyasträ , the weapon of fire.  Sanskrit literature throws light on meteorological knowledge of the ancient times. Panini, who lived in India about 5th century B.C. describes the rainy season as Pravrish and Varsha. He mentions "Varsha Pramanä ' for the measurement of rainfall and " Ghoshpada" as the measure of the rainfall. The Manu -smiti, an ancient Sanskrit work written in the 2nd century A.D., also contains a number of meteorology references. Kautilya alias Chanakya, a Minister of Chanagupta during the 3rd century B.C. has covered the theory of socioeconomics and duties of superintendent of Agriculture in his Arthashastra" . These chapters describe in detail, work on agriculture, measurements of rainfall and elimates of different parts of the country. Kuatilya's description also indicates that ancient Indians were using detailed observations of clouds for rainfall prediction. Varahamihira's Brihat Samhita (505-587 A.D. ) an encyclopaedia of ancient 

Indian culture shows that the science of  teorology was developed in ancient India by sages like Garga, Parasara, Kasyapa, Rsiputra and Siddhasana. These sages had explained formation, properties and prediction of rainfall, in detail. Signs of moderate, excess and scanty rainfall based on observations of clouds in different periods of time in terms of planetary positions are explained in the Rig Veda. Astrologers used to play an important role in prediction of rainfall and subsequent crop yield. Observations on direction of wind, colour and size of clouds, moon's conjunction with asterisms in different months, sun's heat, and behaviour of birds and animals were the principal elements considered for the prediction of rainfall in those days. Different methods of and periods for measurement of rainfall were also available in ancient time. Bhaskara and Aryabhatta, the notable mathematician-astronomers during the 5th century A.D. developed simple instruments like astrolabe for measuring altitude. A number of important developments in astronomy and meteorology were seen during 5th century to 14th century. Scientific meteorology was initiated in India with the establishment of astronomical and meteorological observatories at Madras in 1792-93. Thus, we can see that the present day techniques of observations, measurement and prediction of rainfall have deep roots in the ancient India, millennia ago.