Behavior of Kelvin waves for two low latitude stations

The wind profiles of Jakarta (Indonesia) and Hyderabad (India) have been analyzed from the radiosonde data for 12 months (January to December 2019) and the data have been used to investigate the behavior of Kelvin waves in the equatorial atmosphere. A non-dispersive wave of zonal wind easterlies are recorded between 15 and 25 km altitude in January over the Jakarta region with zero perturbation of meridional wind velocity at the same altitude. Similar pattern with less magnitude of easterlies has also been recorded over Hyderabad region at the same period. This might be an apparent evidence for the decay of Kelvin waves as they move away from the equator and the two regions have a nearly opposite trend of wind profiles. Further effect of Kelvin waves on the atmospheric pressure has been investigated for both the regions at three different altitudes including 5, 15 and 25 km, respectively. The observed effect indicate the existence of kelvin waves depend on the decrease of pressure. Therefore, there is nearly four months interval for the shifting of an intertropical conventional zone (ITCZ) from Jakarta to Hyderabad latitude.