Atmospheric Aerosol: heating and cooling agent of Earth’s Climate

Global warming is the major concern for the mankind in the 21st century. This has been mainly brought about by the human activities which have been producing aerosols (particles and gasses) in ever increasing numbers. Atmospheric aerosols are micron size particles dispersed in the atmosphere and which affect the radiation balance globally. However, the global models have several limitations due to high level of heterogeneity of the aerosols and their resident time scales in different seasons. Hence experimental measurements of number concentration these particles and their properties over different regions are essential to make accurate prediction.

The optical and physico-chemical properties of the aerosols at a given location mainly depend on the local and surrounding source regions of aerosol formation. Spatial distribution of aerosols and their heterogeneity is strongly influenced by the long-range atmospheric transport, vertical mixing, altitude distribution of aerosols, aerosol abundance and types in the source regions and the prevailing aerosol removal mechanisms. The spatial and temporal in-homogeneities in surface, columnar and vertical aerosol characteristics, the influence of special features of climate cycle (for instance monsoon), mixing processes and their intricate interaction with clouds over different size scales (local, regional, meso-scale) impose large uncertainties in understanding the regional as well as global climate change. This is particularly important for the Indian subcontinent with all its natural diversities, high population density, diverse living habits and the growing industrialization and urbanization.

I will present the experimental study undertaken at Hyderabad and the surrounding regions of Bay of Bengal and show the variety and abundance of these aerosols, their vertical and columnar behaviour during different weather seasons and their impact on the atmospheric heating and radiative forcing.

About Dr. P.R. Sinha:

P.R. Sinha is presently working in TIFR, Balloon Facility, Hyderabad since April 2007. He passed his M.Sc. degree in Physics form School of Physics and Astrophysics in Pt. Ravishankar Shukla University in Raipur. He was selected for the Diamond Jubilee Research Internship Fellowship Award of Council of Scientific & Industrial Research (CSIR) in 2005. As part of this program; he spent two years at NPL, Delhi and worked in the Radio and Atmospheric Science Division. He has been working on problems related to Aerosol Dynamics, Aerosol Radiative Forcing, Aerosol-Cloud interaction and Aerosol-Boundary Layer interactions. He has participated in several National field campaigns over Land and Ocean.
In January 2010, he was selected for the European Research Course on `Atmospheres', held at University of Joseph Fourier, France. He has published 13 research papers peer reviewed journals in the field of aerosol science.