Annual fallout of 32Si,210Pb,22Na,35S and 7Be in rains in India

Lal, D. ; Nijampurkar, V. N. ; Rajagopalan, G. ; Somayajulu, B. L. K. (1979) Annual fallout of 32Si,210Pb,22Na,35S and 7Be in rains in India Proceedings of the Indian Academy of Sciences, Section A, 88 (1). pp. 29-40. ISSN 0370-0089

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The concentration of radioisotopes 7Be, 35S were measured in Bombay since 1956 and 22Na, 210Pb, 32Si since 1963. In Khandala and other stations such measurements have been made at irregular periods since 1961. In addition several measurements especially that of 32Si were made in 1970. Data available todate from Indian stations is summarised and critically analysed. We conclude that appreciable amounts of 35S, 22Na and 32Si, over and above their production by cosmic rays, were produced during the high yield Russian tests as evidenced by their fallout between 1962-66. Based on the bomb produced excess the half period for their removal from the stratosphere is deduced to be less than 1 year. The 'excess' contribution of 32Si due to bombs is, however, small; about 1% of its inventory in the oceans. The present study shows that for stations where orogeny is the principal mechanism of precipitation, the annual fallout is independent of the annual rainfall.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Cosmic Rays; Radioisotopes; Rainwater; Fallout
ID Code:49759
Deposited On:21 Jul 2011 10:17
Last Modified:18 May 2016 04:20

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