Hourly radiosonde observation of humidity and temperature and high resolution vertical wind using the Equatorial Atmosphere Radar during convection over Koto Tabang, Indonesia in CPEA-II campaign

Abstract

Distinct wave perturbations for ~ 2-3 hours were observed during Coupling Processes in Equatorial Atmosphere-II in temperature and vertical wind in the tropopause region (~17-19 km) using hourly radiosonde launchings and high resolution Equatorial Atmosphere Radar observations, respectively over Koto Tabang (100.32°E, 0.20°S) during active convective events. Perturbations in temperature and humidity were found to be strongly anti-correlated in the upper troposphere and lower stratosphere region. Observations suggest that convective storm had increased humidity by a factor of 3-5 in the middle and upper troposphere (water vapour mixing ratio were also increased over convective period); gravity waves were generated near and above tropopause, which were not detected during no-convection period. Hourly temperature observations, which have covered complete life cycle of two convective storms of 7-8 hours, showed a significant enhancement in water vapour mixing ratio up to ~15-16 km height that corresponds to a level of strong wind shear existing below tropopause. There is a significant decrease in temperature around this level of strong wind shear.