Sensitivity for global distribution of AOD due to initial injection height of biomass burning

The aerosol optical depth (AOD) including aerosol types is important output parameters for the model simulation to compare with observed AOD for the evaluation of models, and to identify the emission source of aerosols over specific regions. However, several aerosol transport models in the atmospheric general circulation models (AGCMs) still remain the large uncertainties, and the uncertainties affect quantifying the simulation for accurate emission source and cloud interaction processes by aerosols in the atmosphere. One of main reason for uncertainties of global distribution of AOD is the discrepancy of aerosol vertical distributions due to the initial injection height from the emission sources. Because of the vertical distribution of wind field, different initial injection height of aerosol from emission sources affects the transport patterns of aerosols near the source region.

To estimate the sensitivity of initial injection height of aerosols, we used the global aerosol transport model coupled to atmospheric general circulation model, MIROC-SPRINTARS, as a tool for the simulation with high spatial (T213) and temporal resolution (30 minutes intervals) in this study. From MIROC-SPRINTARS simulation, regional discrepancy of AOD between observation and model simulation has different characteristics as compared to pattern of global discrepancy, and this regional characteristic can be thought to the injection layer of aerosols near the source region. In this study, we considered the change of the initial conditions for the aerosol vertical distribution into the aerosol transport model simulation. By different aerosol vertical information, we purposed to find the sensitivity of aerosol transport patterns around the wildfire emission and its impact to the radiation.