Study of the structure of upper tropospheric easterlies over Peninsular India during the southwest monsoon Season based on ESE data

Abstract

Exercise Storm Exchange (ESE) is the name given to the project in which a Canberra aircraft equipped with scientific instruments, loaned by the Royal aircraft Establishment, Farnborough, U.K. flew in India for a period of 3 months from 21 June 1972 On studies of atmospheric conditions. One of the studies was to investigate the detailed structure of temperature and wind fields at different levels in the fast upper tropospheric easterly flow which prevails over Peninsular India, during the southwest monsoon season. The aircraft flew between Trivandrum and Bangalore at selected levels between 500 and 100 mb on 25 July 1972.

The study of the data thus collected; showed that small scale variations of significant amplitude are present in the thermal fields at all levels with the result that the thermal wind equation completely breaks down when it is sought to be verified for short distances. In some cases the actual shears differ from the thermal wind by one order of magnitude.