Technical Note: Sensitivity of 1-D smoke plume rise models to the inclusion of environmental wind drag

Abstract

Abstract. We revisit the parameterization of the vertical transport of hot gases and particles emitted from biomass burning, described in Freitas et al. (2007), to include the effects of environmental wind on transport and dilution of the smoke plume at the cloud scale. Typically, the final vertical height that the smoke plumes reach is controlled by the thermodynamic stability of the atmospheric environment and the surface heat flux released by the fire. However, the presence of a strong horizontal wind can enhance the lateral entrainment and induce additional drag, particularly for small fires, impacting the smoke injection height. This process is quantitatively represented by introducing an additional entrainment term to account for organized inflow of a mass of cooler and drier ambient air into the plume and its drag by momentum transfer. An extended set of equations including the horizontal motion of the plume and the additional increase of the plume radius is solved to explicitly simulate the time evolution of the plume rise with the additional mass and momentum. One-dimensional (1-D) model results are presented for two deforestation fires in the Amazon basin with sizes of 10 and 50 ha under calm and windy atmospheric environments. The results are compared to corresponding simulations generated by the complex non-hydrostatic three dimensional (3-D) Active Tracer High resolution Atmospheric Model (ATHAM). We show that the 1-D model results compare well with the full 3-D simulations. The 1-D model may thus be used in field situations where extensive computing facilities are not available, especially under conditions for which several optional cases must be studied.

Space‐based observational constraints for 1‐D fire smoke plume‐rise models

“…One of the most widely used parameterizations is the plume‐rise model developed by Freitas et al [2007], and recently modified to include the effect of horizontal winds [ Freitas et al , 2010]. The plume‐rise model uses a prognostic scheme for simulating plume heights for tropical fires.…”

“… Freitas et al [2007]demonstrated, using Atmospheric Infrared Sounder (AIRS) and aircraft observations, that explicitly accounting for fire smoke injection processes significantly improves regional atmospheric model predictions of tropospheric CO across the central Amazon. However, at present, the validation of this plume‐rise model has focused only on three case studies: the Quinault fire described by Trentmann et al [2002] [see also Freitas et al , 2007] and two simulated fires with the 3‐D Active Tracer High Resolution Atmospheric Model (ATHAM) [ Freitas et al , 2010].…”

Biomass burning emissions disturbances on the isoprene oxidation in a tropical forest

“…During SAMBBA campaign, we also detected the presence of similar plumes during the flight B742, classified mostly as FP, with a unique CO mixing ratio value, peaking ~5,000 ppbv at about 600 m. These results demonstrate the strength of vertical transport during a fresh 260 biomass burning event, with the plume injection height up to 2 km. Freitas et al (2006Freitas et al ( , 2007Freitas et al ( , 2010 highlighted the importance of representing the injection height of biomass burning plumes in numerical models to describe the regional smoke distribution. and some forest studies (up to 600 ppbv) conducted by Andreae et al (1988), Kaufman et al (1992) and Yokelson et al (2007).…”

Numerical Study of the Transport and Convective Mechanisms of Biomass Burning Haze in South-Southeast Asia

“…PREP-CHEM-SRC integrates emissions inventories and forest fire hotspots onto a specified domain. The biomass burning emissions were estimated using the Brazilian Biomass Burning Emissions Model (3BEM; Longo et al, 2010) and were injected into the atmosphere using the plume rise model described in Freitas et al (2006Freitas et al ( , 2007Freitas et al ( , 2010. The forest fire hotspots database integrated in the model includes a combination of the MODIS fire locations database (U.S.…”