Sudden Cosmic Noise Absorption at 29 Mc/s

Abstract

Cosmic radio noise observations at 29 Mc/s made at Hyderabad, India (17° 26' N., 78° 27' E.), have been compared with solar flare data for the year 1958. For flares of importance 3 or 3±, there is a correlation of 84% with regard to related effects observed in the cosmic noise records. These effects are either enhanced radio emission or SCNA's. Particular study of the 9 SCNA's observed during the year and comparison with results of Bhonsle working at Ahmedabad, India (23° 02' N., 72° 38' E.), reveal that (a) even in the case of intense flares initial conditions in the terrestrial atmosphere govern the production and maintenance of an SCNA, and (b) therefore, at least at frequencies above 25 Mc/s, SCNA's cannot be used for patrolling even intense solar flares.