Buoyant Plume Calculations

Abstract

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Upper Atmosphere Smoke Injection from Large Areal Fires

“…Additionally, for the cases with moisture, the effects of a radiation parameterization are also evaluated. Although previous studies (Penner et al, 1986) found that plume rise is very sensitive to the fuel burned (and, therefore, the amount of energy released), changes in fuel loading are not considered here. Our simulations all employ a homogeneous wildland fuel bed of about 1.3 g cm -2 .…”

“…12, where a metric for lofting (the height above which 50% of smoke is lifted) is plotted for each case and fire size. We compare our final vertical smoke profiles with those of Penner et al (1986) and Reisner et al (2018) in Fig. 13.…”

“…ABL stability, hereafter also referred to as atmospheric stability, may enhance or reduce a large fire's intensity, which in turn affects the probability it will mature into a firestorm (Cotton, 1985;Penner et al, 1986). Past studies have indicated that a stable atmosphere will dampen convection strength, while a more convective atmosphere will enhance lofting capacity.…”

“…Most GCM-based studies are initialized with a certain amount of smoke loading at a specified injection height, based on the size and number of weapons considered. These altitudes are often informed by observations from mass fires, such as in Hamburg during the second world war, or on 1980's simulations using mesoscale models that were driven by energy release rates (Penner et al, 1986;Small & Heikes, 1988;Turco et al, 1990). Using this method, Robock, Oman, Stenchikov, Toon, et al (2007), Toon et al (2007), Toon et al (2008), and Coupe et al (2019) found that, given an exchange with the strategic weapons allowed under treaties between the U.S. and Russia, a nuclear winter is a possible outcome.…”

“…PyroCu and pyroCb development is sensitive to local environmental moisture (Fromm et al, 2010;Lareau & Clements, 2016;Peterson et al, 2016), and as previously mentioned, these phenomena can generate deep convection. Additionally, wind speeds determine whether or not a mass fire develops into a conflagration or a firestorm-the latter of which causes much deeper smoke lofting (Glasstone & Dolan, 1977;Cotton, 1985;Penner et al, 1986). In the context of climatic forcing by upper atmosphere aerosols, it is important, therefore, to have localized estimations of plume rise.…”