Particulate Pollution and Daily Surface Rainfall: Observational Study over Indian Summer Monsoon Region
Tuesday, June 16, 2015: 4:45 PM
Chandan Sarangi, Indian Institute of Technology, Kanpur, Department of Civil engineering, Kanpur, India, Sachchida Nand Tripathi, Indian Inst Technology, Kanpur, India, Vijay P Kanawade, Lund University, Department of Physical Geography and Ecosystem Science, Lund, Sweden, Ilan Koren, Weizmann Institute of Science, Rehovot, Israel and Sivanada Pai, Indian Meteorological Department, Pune, India
Abstract:
Impact of particulate pollution or aerosols on clouds and surface rainfall is an extremely important and mostly uncertain subject, particularly for continental environments. The Indian summer monsoon provides a major portion of annual rainfall over India. However, the aerosol-cloud-rainfall associations during Indian monsoon is still not understood. Using a decade of satellite and in-situ observed datasets, we found a striking positive association between aerosol loading and daily surface rainfall over the core region of Indian summer monsoon. This relationship is supported by compelling evidence of aerosol-induced cloud invigoration, from cloud macrophysical as well as microphysical observations. The positive associations were found to be robust even when the analysis was subjected to spatial, thermodynamical and meteorological slicing. Coherent observations of aerosol-induced widening and deepening of clouds, intensification of precipitation rate, as well as, daily rainfall logically suggest an increase in surface water with increase in aerosol loading. Hence, this study not only demonstrates the importance of aerosol microphysical aspect but also is a major step forward in understanding the impact of pollution on surface water availability over this region of climatic significance.
