We show substantial improvements in the near-surface BC mass concentrations simulated by a regional chemistry transport model, WRF-Chem, over the Indian region, upon scaling up the CMIP5 equivalent anthropogenic BC emissions by 3 and introducing a diurnal variation to those. The diurnality in emissions alone significantly controls the simulated near-surface BC mass concentration, with a mean delay of 3–4 h. The simulated AOD, however, is still underestimated.