Validation of the Institute of Atmospheric Physics emergency response model with the meteorological towers measurements and SF6 diffusion and pool fire experiments

The urban canopy layer parameterization (UCP), a successive bias correction method (SBC), an atmospheric dispersion module for denser-than-air releases, and the emission intensity of chemicals monitored by a Fourier-transform-infrared remote sensor (EM27) were incorporated into the Institute of Atmospheric Physics emergency response model (IAPERM). IAPERMʹs performance was tested in Beijing using the field data collected from a 325-m meteorological tower and sulfur hexafluoride (SF6) diffusion and pool fire experiments. The results show that the IAPERM simulations of the vertical wind speeds in the urban canopy layer (UCL) with the UCP perform much better than those with the Monin–Obukhov similarity parameterization scheme. The IAPERM forecasts for air temperature and relative humidity are more accurate than those for wind speed and direction, which require correction. When the SBC with the local terrain effect is adopted, the wind speed and direction and the maximum concentrations of black carbon near the ground are well forecasted. IAPERM reproduces the spatial distributions of the SF6 observations more accurately near the release source (≤500 m) than at locations far away from the release source with the use of the observed meteorological parameters. These results suggest that IAPERM could be a promising tool for passive and dense gas diffusion simulations or forecasts.