A review of approaches to estimate wildfire plume injection height within large-scale atmospheric chemical transport models

Abstract

Abstract. Landscape fires produce smoke containing a very wide variety of chemical species, both gases and aerosols. For larger, more intense fires that produce the greatest amounts of emissions per unit time, the smoke tends initially to be transported vertically or semi-vertically close by the source region, driven by the intense heat and convective energy released by the burning vegetation. The column of hot smoke rapidly entrains cooler ambient air, forming a rising plume within which the fire emissions are transported. The characteristics of this plume, and in particular the height to which it rises before releasing the majority of the smoke burden into the wider atmosphere, are important in terms of how the fire emissions are ultimately transported, since for example winds at different altitudes may be quite different. This difference in atmospheric transport then may also affect the longevity, chemical conversion, and fate of the plumes chemical constituents, with for example very high plume injection heights being associated with extreme long-range atmospheric transport. Here we review how such landscape-scale fire smoke plume injection heights are represented in largerscale atmospheric transport models aiming to represent the impacts of wildfire emissions on component of the Earth system. In particular we detail (i) satellite Earth observation data sets capable of being used to remotely assess wildfire plume height distributions and (ii) the driving characteristics of the causal fires. We also discuss both the physical mechanisms and dynamics taking place in fire plumes and investigate the efficiency and limitations of currently available injection height parameterizations. Finally, we conclude by suggesting some future parameterization developments and ideas on Earth observation data selection that may be relevant to the instigation of enhanced methodologies aimed at injection height representation.

Contributions of natural and anthropogenic sources to ambient ammonia in the Athabasca Oil Sands and north-western Canada

“…We have added 2013 forest fire emissions which were originally created for the 2013 FireWork forecasts to the anthropogenic point-source emissions used in the base case simulation, and have modified the GEM-MACH model to be able to accommodate the changing number of major point sources each day (as the number of fires changes daily). Fire plume rise is an ongoing area of investigation (e.g., Heilman et al, 2014;Paugam et al, 2016); smoldering emissions tend to be emitted directly at the surface, whereas flaming emissions can inject plumes to the upper troposphere. Here, we have set all fire emissions to be distributed evenly throughout the boundary layer, which is a simplification but one that averages out smouldering and flaming plume heights.…”

Two global data sets of daily fire emission injection heights since 2003

“…When a fire is in the flaming combustion stage, the intense heat from the burning vegetation creates a rising plume which interacts with the ambient atmosphere and transports the fire emissions vertically (Freitas et al, 2006;Paugam et al, 2016). Because of this fire-induced convection, biomass burning is one of the few processes that emits large quantities of aerosols and trace gases well above the planetary boundary layer (PBL), sometimes even reaching the upper troposphere/lower stratosphere (Andreae et al, 2004;Fromm et al, 2005;Dahlkötter et al, 2013).…”

“…The algorithms available today are summed up in Paugam et al (2016) and Veira et al (2015a). They can be divided into two families: semiempirical models (Achtemeier et al, 2011, andSofiev et al, 2012, for example) and numerical one-dimensional plume rise models (PRMs) such as the one developed by Latham (1994) and further refined by Freitas et al (2007) and others.…”

The importance of plume rise on the concentrations and atmospheric impacts of biomass burning aerosol

“…Val Martin et al (2010) indicated that both the fire intensity and the stability of the atmosphere are crucial for the effective source height. A recent review of the representation of plume injection heights in atmospheric models was performed by Paugam et al (2016).…”