Some aspects of the convective boundary layer structure over complex terrain in tropical semiarid regions of rayalaseema

This study documents the dynamics and evolution of elevated stable layers (ESL) over complex terrains around Gadanki valley in tropical semiarid region of southern India during different seasons. The data used in this study were obtained from L-band lower atmospheric wind profiler radar (hereafter LAWP or WPR), Joss-Waldvogel Disdrometer (JWD), optical rain gauge (ORG) and Automatic Weather station (AWS). The analysed boundary layer structure shows a strong influence of the underlying terrain. Until noon, a nearly terrain following capping inversion developed. However, advective processes proved to play an important role in the boundary layer structure over the hilly terrain. So, the large-scale air flow caused suppression of the convective boundary layer growth at the mountain ridge by forcing the capping inversion towards the elevation of the terrain. The advection of cold air by up-slope winds lowered the heating rate near the ground and was able to generate an inversion above the up-slope wind layer. In the late afternoon, the terrain following structure of the capping inversion diminished and the capping inversion tended to form. This study illustrates the importance of understanding the synoptic and mesoscale meteorological processesassociated with convective boundary layer evolution in topographic regions of different seasonal climatic variability.