Estimation of equatorial wave momentum fluxes using MST radar winds observed at Gadanki (13.5 degrees N, 79.2 degrees E)

A method of computing the vertical flux of zonal momentum (associated with equatorial waves) from the zonal and vertical components of the winds measu red by the Indian MST radar at Gadanki (13.5 degrees N, 79.2 degrees E) is presented. The application of the method to the radar data gives flux value s of 16 x 10(-3), 8.0 x 10(-3) and 5.5 x 10(-3) m(2) s(-2) for slow Kelvin (12-day period), fast Kelvin (5.33-day period) and Rossby-gravity (RG) (3.4 3-day period) waves, respectively, in the upper troposphere. These flux val ues compare quite well with the values 4 x 10(-3) m(2) s(-2) and 1 x 10(-3) m(2) s(-2) obtained from radiosonde zonal wind and temperature data by Wal lace and Kousky (1968) for slow Kelvin and RG waves, respectively. An estim ate of the error in the fluxes gives a value of similar to 1.2 x 10(-3) m(2 ) s(-2). (C) 1999 Elsevier Science Ltd. All rights reserved.