Analysis of propagation of complex fire: case of the Yarnell Hill Fire 1

Abstract

We examine the propagation of the Yarnell Hill Fire in Arizona, June 28 --July 3, 2013 to assess the nature of its complexity. We identify the critical fire growth that starts about 35 hours after the fire initiation. In a time span of three hours, the fire area is doubled. Within the following four hours, the direction of fire turns by about 180 degrees. An hour later, a pyrocumulonimbus cloud is observed above the fire area. To monitor complex fires, we propose implementation of an IR instrument to scrutinize fire remotely for behaviors, such as vortices and rotation, arising from combustion events, terrain characteristics, and outside influences. We propose a small reconnaissance plane circling to the side and above the fire area to search for anomalies in fire propagation and atmosphere during the fire consolidation during the initial 45 hours. Ideally, the observing instrument would be sensitive in IR region at about 4.5 microns where carbon oxide emits and water transmits the radiation.

Propagation dynamics of a mountain fire: case of the Yarnell Hill Fire 2

“…1) for the propagation of a fire initiated near a mountaintop that explains significant features of the Yarnell Hill Fire. [4,5,6] Fig. 1.…”

Effects of Density Current, Diurnal Heating, and Local Terrain on the Mesoscale Environment Conducive to the Yarnell Hill Fire

“…Other studies have examined fire propagation and its complexity [17] and developed a novel model for fire evolution [18]. Neither study examined the thunderstorm outflow.…”

“…Prior research on Yarnell [17][18][19][20][21][22] has shown that the numerical prediction of wind surges remains challenging because of the lack of understanding of fundamental dynamical processes at the complex terrain scale. Improving the understanding of multi-scale atmospheric processes that control the motion and longevity of extreme fire events is vital.…”

Characterizing Thunderstorm Gust Fronts near Complex Terrain

“…GFs can be associated with strong turbulence and rapid wind increase and shear creating potential dangers to humans and structures. During the 2013 Yarnell Hill Fire in Arizona, for example, 19 firefighters were killed because of rapid and severe changes to the fire's behavior, driven by a GF moving over the fire (Hardy and Comfort 2015;Paez et al 2015). Tragic events such as this one give incentive to the wildland fire community and emergency responders to better understand the evolution of GFs in areas of complex terrain (Joint Fire Science Program 2017).…”