Publications

Madala, S; Salinas, SV; Wang, J; Liew, SC (2019). Customization of the Advanced Research Weather Research and Forecasting model over the Singapore region: impact of planetary boundary layer schemes, land use, land cover and model horizontal grid resolution. METEOROLOGICAL APPLICATIONS, 26(2), 221-231.

Abstract
Accurate simulations of surface meteorological variables are important for the transport and dispersion of air pollutants and air quality in the lower atmosphere. In the present study, the surface meteorological variables over Singapore were simulated using the Advanced Research Weather Research and Forecasting (WRF-ARW) mesoscale model. The sensitivity tests were conducted with six different planetary boundary layer (PBL) schemes (Yonsei University, Mellor-Yamada-Janjic, University of Washington, Asymmetric Convective Model version 2 [ACM2], Bougeault-Lacarrere, Quasi-Normal Scale Elimination), four different horizontal grid resolutions (27, 9, 3 and 1 km) and two different land use, land cover datasets (US Geological Survey [USGS] and Moderate Resolution Imaging Spectroradiometer [MODIS]). Eight days (January 20-28, 2015) were selected for the WRF-ARW model simulations for simulating surface meteorological variables. The model results were validated with available observations over the Singapore region. A lower mean bias, mean absolute error and root mean square error and good correlation were found in calculating surface meteorological variables with increase in the WRF-ARW model horizontal resolution up to 3 km. Further, MODIS land use, land cover datasets considerably improved the prediction of surface meteorological variables compared to the USGS for all PBL schemes and horizontal grid resolutions. Qualitative and quantitative analyses of the surface meteorological variables simulated using the ACM2 PBL scheme with 3 km horizontal grid resolution with MODIS land use, land cover data are in better agreement with observations with less error and a good correlation coefficient. The better performance by ACM2 could be due to non-local turbulence closure during unstable conditions and local closure during the stable and neutral conditions formulated in this scheme. Overall, this study indicates possibilities to improve regional level air quality monitoring and prediction capabilities over Singapore.

DOI:
10.1002/met.1755

ISSN:
1350-4827