Table 3.

Issues and gaps for fire and smoke model improvement.

Field	Process	Issues and gaps
Fire behavior and energy	Heat release	Need measurements of unit heat release per unit area along the fire perimeter; Improve vertical distribution of radiative and convective heat flux generated by the fire; Understand the relations between heat structure and multiple sub-plumes.
	Fire spread	Parameterization of lateral fire progression may underestimate the lateral fire spread, burnt area and the total buoyancy of the fie plume
Smoke and meteorology	Plume distribution	Plume top heights are often provided with large uncertainty, and without the vertical concentration profiles which are generally specified not resolved based on fire dynamics and local weather conditions
	Multiple sub-plumes	No routine measurements are available; Some modeling tools are in early development stage; Parameterization schemes are needed.
	Smoldering combustion and night smoke	Bulk emission factors not dependent on the burning stage; Night-time smoke drainage modeling has many assumptions; Not evaluated for burned sites with complex topography.
	Fire-atmosphere interactions	Need measurements of all at commensurate spatial and temporal scales to predict and validate interactions between vegetation, wind fire behavior and plume dynamics; Coupled fire-atmosphere models and air quality models.
	Smoke-air interactions	Improve entrainment estimates; Better characterize smoke optical properties; Understand the impacts of pyro cumulus on vertical smoke distribution and fire behavior.
Emissions and chemistry	Pollutants with distance and time	Lack in near-event and downwind measurements of O3, PM2.5, their precursors and important chemical intermediate species.
	PM and gas speciation	PM, VOC, and nitrogen gas speciation not very well understood for different fuel types and combustion conditions.