Local and Regional Interactions Between Air Quality and Climate in New Delhi -- a Sector Based Analysis

Out of the 26 mega-cities in the world, 13 of them are affected by atmospheric brown clouds with high aerosol loadings and 5 of them are in South Asia. New Delhi (India) is one of the world's most polluted megacities. In this study we evaluate the air pollution levels in Delhi and their impacts on weather and climate. The two way interactions between pollution and meteorology are evaluated using the WRF-Chem model. The analysis period is focused on October 2010, the time period of the Commonwealth Games. The model is compared to BC and PM2.5 measurements at 11 sites. A sector based analysis is performed to assess the contributions to pollution and direct radiative forcing from transport, residential, power and industrial emissions. The contributions from emissions outside of Delhi are also evaluated to see the extent that regional emissions need to be controlled to meet air quality targets in Delhi. Results of simulations for emission scenarios generated by the GAINS model that address air quality and climate strategies are also discussed