Predicted and measured concentrations of traffic carbon monoxide over Delhi

Carbon monoxide concentration due to vehicular traffic in urban Delhi has been computed by using an analytical dispersion model (IITCO), Pollution Episodic Model (PEM) and Intersection Midblock Model (IMM). While IITCO has been developed in IIT, the other two are operational models in the U.S.A. Computations from models are compared with observations collected at ITO, Janpath, Nazafgarh and Townhall. On-site measurements of CO are taken by using real time analyzers and meteorological parameters are obtained from a micrometeorological tower at IIT Delhi. The model results compare well with observations. The performance of IITCO is compared with PEM and IMM and found to be quite satisfactory. The diurnal variation of concentration is also found to be in good agreement with the diurnal variation of traffic volume.