Simulation of Daily Variation of Suspended Particulate Matter over Delhi: Relative Roles of Vehicular Emission, Dust, and Domestic Appliances

The massive growth in the size and the population of cities over the past few decades has led to serious deterioration in the quality of air. One of the important constituents of airborne pollutants, which is a major health hazard, is suspended particulate matter (SPM). SPM is also an important source of cloud condensation nuclei; accurate simulations of SPM with sufficiently long lead thus have many applications, from issuing health advisories to forecasting fog. One of the biggest challenges in modeling air pollution in general and SPM in particular is to identify and mathematically represent the (location specific) sources and sinks. In this study the authors present a dynamical model for daily values of SPM over Delhi, India. The meteorological parameters are taken from the daily values from NCEP reanalysis. The validation is carried out against observations generated by the Central Pollution Control Board (CPCB) in India for the period 2000–05. Error statistics show that the model can capture a significant part of the observed variability of SPM. An evaluation of the relative contributions of various sources show that while vehicular pollution accounts for a large fraction of the SPM throughout the year, steep increases in the winter and the premonsoon periods are accounted for by fossil fuel burning and wind blown dust, respectively. Simulation with a doubling scenario for traffic congestion shows the effect to have strong seasonality. Such a model can be also interfaced with a seasonal forecast model or a climate model for enhanced scope of seasonal forecasts or for an investigation of the impact of SPM on regional climate change.