High-level Summer Warmings & Their Possible Association with Monsoon

Abstract

The stratospheric and mesospheric warming’s reported in literature refer to winter and spring periods. Seldom there is mention of the occurrence of such warming’s in summer. It is considered that the thermal behaviour of stratosphere and mesosphere over tropical stations in summer may have a bearing, at least on gross scale, on the activity of summer monsoon. With this end in view, the available Soviet rocket data for Thumba (8o32'15”N; 76°51'48”E), of the three summer periods commencing from 1971, are examined. The study revealed the phenomenon of high-level warming’s over the station. The behaviour of the monsoon, when such phenomenon occurred, differed from that of the monsoon when it did not occur. Similar feature was also inferred from analysis of radiosonde data. The problem was further examined througl1 analysis of the rocket data of the pre-summer periods. The possibility of such data reflecting the behaviour of the approaching monsoon was indicated.