Studies on equatorial waves over the Indian zone

As part of the Indian Middle Atmosphere Programme, three scientific campaigns were conducted to study equatorial waves in 1984, 1986 and 1988 from Trivandrum, SHAR and Balasore involving RH 200 rockets and balloonsondes for measurement of horizontal wind components. With the installation of MST radar and Rayleigh lidar at Gadanki, temperature could be determined in the middle atmosphere, enabling estimation of vertical flux of zonal momentum of the equatorial waves, which is a crucial parameter to understand the role of the equatorial waves in the generation of quasi biennial oscillation and semi annual oscillation. Making use of these facilities, three more campaigns were conducted to delineate the equatorial wave characteristics, including the wave momentum flux. The results of each of these campaigns have already been published. Here the results from all the six campaigns are reviewed, consolidated and examined in the light of the current global scenario of equatorial wave studies.