The accurate prediction of wildfire behavior and spread is possible only when fire and atmosphere simulations are coupled. In this work, we present a mechanism that causes a small fire to intensify by altering the atmosphere. These alterations are caused by fire-related fluxes at the surface. The fire plume and fluxes increase the convective available potential energy (CAPE) and the chance of the development of a strong pyroconvection system. To study this possible mechanism, we used WRF-Fire to capture fire line propagation as the result of interactions between heat and moisture fluxes, pressure perturbations, wind shear development and dry air downdraft. The wind patterns and dynamics of the pyroconvection system are simulated for the Horse River wildfire at Fort McMurray, Canada. The results revealed that the updraft speed reached up to 12 m/s. The entrainment mixed the mid and upper-level dry air and lowered the atmospheric moisture. The mid-level and upper-level dew point temperature changed by 5–10 ${}^{\circ }$ C in a short period of time. The buoyant air strengthened the ascent as soon as the nocturnal inversion was eliminated by daytime heating. The 887 J/kg total increase of CAPE in less than 5 h and the high bulk Richardson number (BRN) of 93 were indicators of the growing pyro-cumulus cell. The presented simulation has not improved the original model or supported leading-edge numerical weather prediction (NWP) achievements, except for adapting WRF-Fire for Canadian biomass fuel. However, we were able to present a great deal of improvements in wildfire nowcasting and short-term forecasting to save lives and costs associated with wildfires. The simulation is sufficiently fast and efficient to be considered for a real-time operational model. While the project was designed and succeeded as an NWP application, we are still searching for a solution for the intractable problems associated with political borders and the current liable authorities for the further development of a new generation of national atmosphere–wildfire forecasting systems.

中文翻译：

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野火热对流和CAPE：浮力的干燥和大气强度—麦克默里堡

仅当将火和大气模拟耦合在一起时，才可能准确预测野火行为和蔓延。在这项工作中，我们提出了一种机制，该机制会通过改变气氛来引起小火加剧。这些变化是由表面火相关的通量引起的。火羽和通量增加了对流可用势能（CAPE），并增加了形成强热对流系统的机会。为了研究这种可能的机制，我们使用WRF-Fire来捕获火线传播，这是热与湿通量，压力扰动，风切变发展和干燥空气向下气流之间相互作用的结果。对加拿大麦克默里堡的Horse River野火模拟了热对流系统的风型和动力学。结果表明，上升速度达到了12 m / s。夹带混合了中高层干燥空气并降低了大气湿度。中层和上层露点温度变化5-10 ${}^{\circ }$ C在短时间内。白天取暖消除了夜间反转后，浮力的空气便增强了上升的速度。在不到5 h的时间内，CAPE的总增加量为887 J / kg，高散装理查森数（BRN）为93，这是热释积细胞生长的指标。除了使WRF-Fire适应加拿大的生物质燃料外，本仿真还没有改善原始模型或支持先进的数值天气预报（NWP）的成就。但是，我们能够在野火临近预报和短期预报方面进行大量改进，以节省与野火有关的生命和成本。该仿真足够快且有效，可以考虑用于实时操作模型。该项目是作为NWP应用程序设计并成功完成的，