Inaugural Lectures by Fellows/Associates

Chemistry–Climate Interaction Over the Eastern Himalayan Foothills Region

The eastern part of the Eastern Himalayan Foothills region is dominated by biomass burning emissions, while fossil fuel generated trace gases and aerosols override the western part. The columnar aerosols burden exhibits a strong seasonality, a west to east longitudinal (decreasing) and an altitudinal (inverse) gradient. Both columnar aerosol loading and O3 in the region stand second highest in South Asia next to IGP. ll surface level pollutants: PM, BC, CO and NOx, except O3 possess similar seasonality. The non-linearity between O3 and NOx suggests O3 formation in a NOx saturated, VOC sensitive regime. The aerosol radiation interaction, aerosol-cloud interaction, stratosphere-troposphere exchange during normal and extreme weather events, lightning activities producing NOx and O3, convective activities leading to elevated aerosol layers are critical over the region. Comprehensive research in these areas including the speaker’s contributions has enriched the knowledge about South Asian chemistry-climate interaction and understanding of the climate change mechanisms.