Behavior of Kelvin wave for two low latitude stations

Abstract

The wind profiles of Indonesia and Hyderabad (India) is collected from the radiosonde data from 01 January 2019 to 31 December 2019 and It is used to study the behavior of the kelvin wave of the equatorial atmosphere. A non-dispersive wave of zonal wind easterlies noticed between 15 to 25 km altitude in January over the Indonesian region with zero perturbation of meridional wind velocity at the same altitude. In case Hyderabad less magnitude of westerlies is found at 15 to 25 km altitude again with zero perturbation of meridional wind velocity. This is clear evidence of decays of kelvin as it moves away from the equator. This study reveals the behavior of kelvin wave at the equator and a low latitude station. It is pronounced that both regions having an almost opposite trend of wind profiles. It is also concluded that it takes approximately four months for the shifting of an intertropical conventional zone (ITCZ) from Indonesian to Hyderabad latitude. To study the effect of Kelvin wave on the atmospheric pressure the three different altitudes are selected that is 5km, 15km and 25km respectively. The altitude 15km is preferred because at this altitude the easterlies are highly dominant and remaining two are reference altitudes.