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Aerosols are tiny liquid or solid particles suspended in the air. They generally produced by anthropogenic and natural sources and thus differ in size and chemical composition. The size and chemical composition of the particles derived their physical and optical properties. The role of atmospheric aerosols is assuming increasingly importance because of their potential health and climate effects. This study was carried out to understand the aerosol physical and chemical properties over Delhi region, particularly the relationship between mass-size distributions, chemical composition (inorganic ions) and trace gases (SO2 and NO2). These findings are useful in understanding the role of aerosols mass and size distribution for constraining their radiative forcing properties.

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Khem Singh has done his Ph.D in the field of "Physico-Chemical characterization of aerosol and precursor gases in & around Delhi" from Jamia Millia Islamia (A Central University), New Delhi (India). He is presently working in CSIR-NPL,New Delhi and is engaged in preparation of Primary gas standards and R&D related to atmospheric aerosols.

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