Research article Sensitivity of PBL parameterization schemes of Weather Research Forecasting Model and coupling with AERMOD in the dispersion of NO X over Visakhapatnam (India) Rahul Boadh, 1 A. N. V. Satyanarayana, 1 * T. V. B. P. S. Rama Krishna 2 and Srikanth Madala 1 1 Centre for Oceans, Rivers, Atmosphere and Land Sciences, Indian Institute of Technology Kharagpur, Kharagpur-721 302India 2 Environmental Impact & Risk Assessment Division, Council of Scientific & Industrial Research-National Environmental Engineering Research Institute, Nagpur 40020, India Received 5 August 2014; Revised 20 January 2015; Accepted 28 January 2015 ABSTRACT: 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. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd. KEYWORDS: WRF; AERMOD; air pollution dispersion; planetary boundary layer INTRODUCTION Various studies have established that air pollution strongly affects human health, [1,2] climate change, [3,4] agriculture, [5,6] and natural ecosystems. [7] There are several sources of air pollution, viz., industrial, power generation, transportation, agricultural and natural sources, Although air quality has begun to improve in the developed world, [8,9] in many countries with ambitious economic growth targets the acceptable levels of air pollution have been transgressed, resulting in an urban skyline characterized by smog and dust clouds. Global population growth, urbanization and industrialization have revealed air pollution as a pitfall associated with the increased use of fossil fuels. [10–12] In several Indian cities with population of over a million, air pollution levels exceeded World Health Organization standards. The estimated pattern of exposures (solid-fuel use) and background health conditions in India, it has been estimated that in India alone, about 500 000 premature deaths are caused each year by indoor air pollution. [13] Various roles served by air pollution models, which cover a broad range of scales from local to global, lead to distinct modeling requirements. The emphasis is on Gaussian-plume type models for continuous releases, which are at the core of most US Environmental Protection Agency (EPA) regulatory models. Rama Krishna et al. estimated assimilative capacity and dispersion of pollutants due to industrial sources in Visakhapatnam bowl area using a Gaussian Dispersion Model. [14] El-Fadel et al. have discussed about the regulatory and compliance-based modeling for air quality impact assessment for predicting future air quality under various management scenarios, particularly where air quality monitoring data are *Correspondence to: A. N. V. Satyanarayana, Centre for Oceans, Rivers, Atmosphere and Land Sciences, Indian Institute of Technology Kharagpur, Kharagpur-721 302, India. E-mail: anvsatya@coral.iitkgp.ernet.in, achanta.satya@gmail.com © 2015 Curtin University of Technology and John Wiley & Sons, Ltd. Curtin University is a trademark of Curtin University of Technology ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING Asia-Pac. J. Chem. Eng. 2015; 10: 356–368 Published online 20 March 2015 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/apj.1876