Session 2C: Inaugural Lectures by Fellows / Associates

Three Dimensional structure of cloud type distribution over the Indian summer monsoon region using space based W-band Radar observations

Abstract: Clouds have an enormous influence on the Earth's energy balance, climate and weather and key factor of the planet's temperature. The observations of clouds are more important for improving and validating the numerical models of Earth's weather and climate predictions. There has been plethora of studies on the spatial and vertical distribution of clouds using various satellite observations. These studies have enhanced the understanding of cloud dynamics and their representation in general circulation models. However, one of the outstanding research problems in cloud realms is the vertical distribution of various types of clouds including multi-layered cloud distribution and their associated dynamics. The present study brought out the three-dimensional distribution of   various types of cloud and their associated dynamics over the Indian Summer Monsoon (ISM) region using space based W-band radar observations on-board CloudSat satellite. The results highlight the preferential regions of occurrence of each cloud type over the ISM region for the first time. The prevailing dynamical features during the ISM period and their role in preferential formation of cloud types over a given region are investigated.  More importantly, the vertical structure of latent heating associated with various cloud types is also discussed. Distribution of vertically resolved multi-layered clouds and the role of large scale dynamics in controlling the formation of multi-layered cloud also studied. Further, I have explored the use of multi-frequency radar observations to improve the retrieval of hydrometeor properties. The significance of the present study lies in establishing the vertical distribution of various types of cloud and including vertically resolved multi-layer clouds and their associated dynamics for the first time. The present results will aid in estimating cloud radiative properties, which will be helpful for evaluating climate models and to study their role in modifying the large-scale atmospheric circulation.

Key words: Cloud types, multi-layered clouds, CloudSat, Indian Summer Monsoon