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Warren E. Heilman, Xindi Bian, Kenneth L. Clark, Nicholas S. Skowronski, John L. Hom, and Michael R. Gallagher

1. Introduction Wildland fires often occur in forested environments. Fire spread and smoke dispersion through these environments are affected by ambient and fire-induced atmospheric circulations, which, in turn, are influenced by the presence of forest vegetation ( Albini and Baughman 1979 ; Ryan 2002 ; Taylor et al. 2004 ; Kiefer et al. 2014 ; Seto et al. 2014 ; Heilman et al. 2015 ). The properties of atmospheric mean and turbulent circulations inside forest vegetation layers in the

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Warren E. Heilman, Xindi Bian, Kenneth L. Clark, and Shiyuan Zhong

1. Introduction Atmospheric turbulence regimes in the vicinity of wildland fires, which often occur in forested environments, can affect fire behavior and the dispersion of smoke ( Clements et al. 2008 ; Mandel et al. 2009 ; Sun et al. 2009 ; Goodrick et al. 2013 ; Simpson et al. 2016 ). Fortunately, recent observational studies during wildland fire events have made great strides in improving our understanding of the evolution and properties of fire-induced atmospheric turbulence regimes

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Alec G. Stephenson, Benjamin A. Shaby, Brian J. Reich, and Andrew L. Sullivan

, to inform land-planning and life-safety management policies, and to issue warnings to the general public. In Australia, where wildfires are more commonly called bushfires, the fire danger rating systems of McArthur (1966 , 1967) are used. These systems combine weather and fuel information to calculate an index of fire danger that is used to define the fire danger rating. Of the two fire danger rating systems in use in Australia, we constrain our focus to the forest fire danger index (FFDI

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Warren E. Heilman, Tirtha Banerjee, Craig B. Clements, Kenneth L. Clark, Shiyuan Zhong, and Xindi Bian

disproportionate amount to the total vertical turbulent heat-flux fields within forest vegetation layers. Although studies of sweep–ejection dynamics in the lower ABL have been numerous over the last four decades, little is known about the sweep–ejection dynamics that occur in the highly perturbed environment surrounding wildland fires. Beer (1991) and Pimont et al. (2009) noted that coherent turbulent structures leading to turbulent heat- and momentum-flux sweep and ejection events within forest

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Amir Shabbar, Walter Skinner, and Mike D. Flannigan

1. Introduction Wildland fire is a dominant disturbance regime in Canadian forests, particularly in the boreal forest region where fire is a process critical to the very existence of primary boreal species such as pine, spruce, and aspen and is responsible for shaping landscape diversity and influencing energy flows and biogeochemical cycling ( Stocks et al. 2002 ). Stocks et al. (1996) examined the spatial distribution of large fires in Canada during the 1980s when an average of almost 10

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E. N. MUNNS

MARCH, 1921. MONTHLY WEATHER REVIEW.EVAPORATION AND FOREST FIRES.By E. N. MUNNS, Forest Examiner. 5s/. 5'73 : 6 34.7. %3'149(California District U. 8. Forest Service, Feb. 17,1021.)EYNOp8IB.Hitherto a arently, little attempt has been made by foresters and t% correlate the factors of climate and forest fires. The m:&z%%is paper ia to show that the occurrence and spread of large fmt fires are coincident with a greatly increased rate of evapora.tion or a decrease in vapor preesure

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Francesca Di Giuseppe, Florian Pappenberger, Fredrik Wetterhall, Blazej Krzeminski, Andrea Camia, Giorgio Libertá, and Jesus San Miguel

1. Introduction Wildfire activity is strongly affected by four factors: fuels, climate/weather, ignition agents, and people ( Flannigan et al. 2005 ). Where fuel is available, weather is the most important factor in shaping fire regimes in many areas of the world ( Flannigan et al. 2009 ). Fires are a global phenomenon extending from the boreal forests of Canada and Siberia down to Amazonia and the central African rain forests. Especially in a savanna ecoclimate, such as the Sahel and west

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Martin P. Girardin and B. Mike Wotton

1. Introduction The Canadian Forest Fire Weather Index (FWI) System ( Van Wagner 1987 ) has been in use across Canada for the past 30 years in the daily operations of fire management agencies ( http://cwfis.cfs.nrcan.gc.ca/ ). The FWI System uses daily weather observations (temperature, rainfall, relative humidity, and wind velocity) to estimate the moisture content of three different fuel classes and uses these to generate a set of relative indicators of potential rate of fire spread, fire

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Paul Fox-Hughes

1. Introduction Over much of the forested area of Australia, a forest fire danger index (FFDI) is calculated using the McArthur Mark V forest fire danger meter ( McArthur 1967 ). McArthur noted that, depending on the density of forest cover, most eucalypt forests would achieve minimum fuel moisture (and therefore maximum capacity to sustain fire activity) during the early afternoon to midafternoon. In the case of many manual observation sites with records stretching over some decades, 0900 and

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A. Garcia Diez, L. Rivas Soriano, and E. L. Garcia Diez

M^Y 1996 GARCIA DIEZ ET AL. 725Medium-Range Forecasting for the Number of Da~y Forest Fires A. GARCIA DXEZDepartment of Mathematics, University of Oviedo, Oviedo, Spain L. R~VAS SORIANO AND E. L. GARCIA DmzDepartment of Atmospheric Physics, University of Salamanca, Salamanca, Spain(Manuscript received 16 March 1995, in final form 6 November 1995)ABSTRACT In an

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