ESTIMATION OF THE INJECTION HEIGHT OF BIOMASS BURNING EMISSION

摘要

The focus of this study islaidon the relation between emitted Fire Radiative Power (FRP) and smoke plume height. Once validated for different weather conditions and different fire characteristics, such a relation could be used to set up a parameterization of fire injection in global atmospheric chemical transport model. The study is based on both numerical simulation and observations. The numerical approach follows a two successive simulations strategy that first focuseson the study of fire radiation. Based on the capability of the WFDS model in fire simulation (and validation on prescribed fires), the model is developed to calculate fire radiation in the middle infra red. The partitioning of the emitted energy between different processes such as radiation and convection is also studied. The second step simulation is based on the plume model developed by Freitas et al. (2007). This plume model is already used in different host models( e.g. WRF, BRAMS). In its current version, the fire is modeled by: a convective heat flux (pre-defined by the land cover and evaluated as a fixed part of the total heat released); and a plume radius which defines the fire extension where the FRP is homogeneously distributed. Here in our approach the Freitas model is modified to use results based on WFDS simulation and observations, to directly force the convective heat flux from FRP data. Validation of this new initialization method is shown by comparing Freitas 1D plume model with MISR data for several test case fires.