Sensitivity of PBL parameterization schemes of Weather Research Forecasting Model and coupling with AERMOD in the dispersion of NOX over Visakhapatnam (India)

An attempt has been made to develop a pre-processor coupler for offline coupling of atmospheric mesoscale model (WRF) with a dispersion model (AERMOD) to estimate the ground level concentrations due to industrial sources over a coastal city, Visakhapatnam, India. To integrate AERMOD in standalone mode, surface and upper meteorological observations and various planetary boundary layer (PBL) parameters with good temporal resolution are required, that are absent for most locations in India. We have developed an integrated WRF-AERMOD modeling system that gets required PBL parameters the pre-processor coupler. Using this model, evaluation of the dispersion of nitrogen oxides (NOX) over Visakhapatnam during summer month with emission inventory of elevated point sources of various industries is conducted. Sensitivity studies of PBL schemes of WRF after validation reveal that the non-local schemes, Yonsei University (YSU) followed by Asymmetric Convective Model version 2 (ACM2), captured well the characteristic variations of surface meteorological variables, vertical atmospheric structure. After validating with monitored air quality data, it is found that the integrated model with YSU followed by ACM2 is good in simulating ground level concentrations of NOX. The present work advocates that the developed modeling system is useful for better assessment of pollution dispersion over coastal regions. (c) 2015 Curtin University of Technology and John Wiley & Sons, Ltd.