Atmospheric Aerosol in Delhi Region and Source Apportionment Using Positive Matrix Factorization

GAZALA HABIB (1), Amrita Singhai (1), Tarachand Lohia (1), Anil J. Kurian (1), Saood Manzer (1,2), Tarun Gupta (3)

(1) Indian Institute of Technology Delhi, (2) Aligarh Muslim University, (3) Indian Institute of Technology Kanpur

     Abstract Number: 407
     Last modified: May 12, 2010

Abstract
Anthropogenic aerosols impact the local air quality, health, and climate in several complex ways. The quantification of these impacts is associated with large uncertainties. The lack of measurement and characterization of aerosols at various parts of India is placing a great hurdle in local air quality and regional climate studies. Therefore, this study was focused on temporal measurement of aerosol at 3 different sites of Delhi city. The background site (~30 m above the ground level) and the 2 road sites (~5.0 m away from road) were chosen for monitoring to investigate the link between aerosol concentrations with regional meteorology, long range transport and source distribution in winter and dry seasons. The fine particles (Dp<=1.0 micro-meter) were collected from October, 2009 to March, 2010 and were analyzed for ions and trace metals. PM1.0 varied seasonally with highest concentration observed during winter (December, 09 and January, 10) and lowest during dry season (March, 10) at all the sites. Night time concentrations were higher than day time concentrations especially in winter season when heavy foggy events were observed. At different sites highest ion concentration were observed in winter and lowest in dry season probably indicating the effect of meteorological parameters. The trace elements did not show any variation in different season. The mass collected on quartz filter will be analyzed for organic molecular marker by GC/MS and will be presented in future. The Positive Matrix Factorization will be used for source apportionment and the source strength at different sites will be discussed. The link between regional meteorology and aerosol concentration will be discussed. The effect of long range transport at background site will be investigated using backtrejectory analysis.