Quantifying the potential for high-altitude smoke injection in the North American boreal forest using the standard MODIS fire products and subpixel-based methods

Abstract

All chemical transport models require an estimation of the vertical distribution of smoke particles near the source. This study quantitatively examines the strengths and weaknesses of several fire products for characterizing plume buoyancy and injection heights in the North American boreal forest during [2004][2005]. Observations from the Multiangle Imaging Spectroradiometer show that 21% of smoke plumes are injected more than 500 m above the boundary layer (BL 500 ) and 8% exceed 2.5 km above ground level. Corresponding observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) show that probability of injection above the BL 500 exceeds 60% for pixel-based fire radiative power (FRP p ) values abovẽ 2500 MW. Increasing values of subpixel-retrieved fire area and temperature also correspond to higher injections but only after removing fire pixels with a weak 11 μm fire signal and clustering. The probability of injection above the BL 500 reaches 50% when the subpixel radiant flux (FRP f flux) exceeds 20 kW/m 2 , highlighting its potential for estimating plume buoyancy. However, these data have limitations similar to FRP p , where the highest probability of injection corresponds to a small percentage of the data set (5-18%), and many high-altitude injections occur with lower values. Examinations of individual smoke plumes highlight the importance of combining pixel-level and subpixel outputs and show that plume injection is also sensitive to the fire pixel spatial distribution and meteorology. Therefore, an optimal method for predicting high-altitude injections will require some combination of injection climatology, FRP p , FRP f flux, and meteorology, but each variable's importance will depend on fire event characteristics.

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

“…Ichoku et al (2012) provide a recent review of this topic. EO data also provide information on the characteristics of the causal fires themselves, including "active fire" (AF) products that detail the location, timing, and FRP of the landscapescale fires occurring within the EO satellite pixels (Giglio et al, 2003;Giglio and Schroeder, 2014;Peterson et al, 2014;Wooster et al, 2012a;Roberts and Wooster, 2008). FRP is a fire characteristic that has been shown to relate quite directly to the total heat produced by the combustion process (Freeborn et al, 2008) and also to the rate of fuel consumption (Wooster et al, 2005), trace gas (Freeborn et al, 2008), and aerosol (e.g.…”

“…More recently Peterson et al (2014) propose the idea of a model predicting the probability of injection above the PBL. Using an implementation of the Dozier (1981) algorithm based on MODIS input data, and 1028 boreal fire plumes extracted from the Northern American subset of the MISR data set, they show that the presence of plume in the troposphere can be independently related to the value of the classical FRP (Justice et al, 2002), fire size, FRP derived from the Dozier algorithm (FRP f ), or the FRP f flux.…”

“…Both inventories are therefore quite difficult to couple to fire emissions inventories and cannot be easily linked to particular fires and therefore to actual emission totals. Capturing the high variability of plume dynamics, estimating InjH, and implementing this within a CTM therefore remains a current topic of very active research Sofiev et al, 2012;Val Martin et al, 2012;Peterson et al, 2014), and the task of this paper is to review the different approaches currently available.…”

Microphysical characterization of long-range transported biomass burning particles from North America at three EARLINET stations

“…It has been demonstrated that large smoke plumes from large forest fires can be injected into the free troposphere, and then easily transported by air masses along the Earth, presenting long residence times in the atmosphere (Andreae, 1991;Fromm and Servranckx, 2003;Jost et al, 2004;Peterson et al, 2014;Seinfeld and Pandis, 2016;GuerreroRascado et al, 2010GuerreroRascado et al, , 2011. The study of these aerosol transport processes is relevant for all aerosol types, since this information is crucial in modeling the global impact of aerosol particles and monitoring events of social relevance .…”

Fire Influences on Atmospheric Composition, Air Quality and Climate

“…Sofiev et al [67] estimated that globally 90 % of emissions were released below 3 km. For 2004-2005 over North America, it was estimated that 8 % of smoke plumes reached more than 2.5 km above the boundary layer [68]; only a small number of these are lofted directly to the upper troposphere. Strode et al [28] indeed found that the influence on tropospheric CO due to biomass burning decreases with height, being smaller at 500 hPa than at the surface.…”