Real-time source apportionment of submicron particle number size distribution in Delhi NCR.

Abstract

Atmospheric submicrometric (<1 μm or 1000 nm) particles contribute a significant mass fraction of the PM2.5, and particles in both size ranges are linked to adverse impacts on human health and atmospheric visibility. Delhi is one of the most polluted regions in the world and routinely experiences some of the world's highest urban particulate matter concentrations. Source apportionment studies have been extensively performed in Delhi. Still, all these studies have focussed on identifying sources and their contributions to particulate matter mass rather than particle number concentration. To the best of our knowledge, no source apportionment study has been conducted in the Delhi region, which focused on the source identification and source contribution of particle number concentration. Hence, in this study, real-time high-resolution measurements of particle size distributions of sub-micron particles (10-1000 nm) and gaseous pollutants will be used to identify and quantify sources contributing to particle number concentration with the help of positive matrix factorization (PMF). Real-time measurements of gaseous pollutants (NO, NO2, SO2, CO, and O3) and meteorological parameters (temperature, relative humidity, RH and windspeed) will also be used further to investigate the potential sources of PNC and formation processes. Further, polar and wind trajectory analyses will be performed to identify the strengths of potential local and distant sources.