| << | Profiling of Aerosols | >> |
Abstract
The significant role of atmospheric aerosols in modulating tropical clouds has far reaching consequences on weather and climate. These aerosol effects are poorly quantified and represent the greatest uncertainty in our understanding of the climate system. Aerosols, in indirect way, tinker with size, shape and location of clouds and how much rain these clouds produce. The changes in number concentration of cloud condensation nuclei (CCN) have significant impact on the micro-physics of clouds, precipitation and thus climate. Taking into account the immense role of clouds and aerosols in regulating the thermodynamics/dynamics of weather and climate over tropics, it is worthwhile to have any additional information from location-specific observations of both direct and indirect methods. In this paper, the results of a comprehensive study made by utilizing an autonomous dual polarization micro pulse lidar (DPMPL) that has been in regular operation at the Indian Institute of Tropical Meteorology (IITM), Pune, India, are reported on the coupling process between aerosols and clouds in a monsoon environment. The polarization lidar back-scattered signal strength profiles up to about 3 km with vertical range resolution of 2.4 m, recorded on some typical experimental days during the south-west monsoon months (June and August 2008) have been used to investigate (i) aerosol-cloud interactions, (ii) aerosol-precipitation relationship and (iii) clear and in-cloud turbulence vertical structures. The results reveal that the sub-cloud layer contributes maximum to the CCN within the cloud cells; and intense in-cloud turbulence as compared to outside the cloud over the experimental site. The study also points out cloud dissipation after drizzle formation and delay in the production of fresh CCN after the wet removal – a phenomenon, popularly known as “Recharging of the Atmosphere”. More details about the lidar, data analysis procedures and explanation to the observed features will be discussed.