A Numerical Study of Atmospheric Perturbations Induced by Heat From a Wildland Fire: Sensitivity to Vertical Canopy Structure and Heat Source Strength
A Numerical Study of Atmospheric Perturbations Induced by Heat From a Wildland Fire: Sensitivity to Vertical Canopy Structure and Heat Source Strength
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野火热量引起的大气扰动的数值研究：对垂直冠层结构和热源强度的敏感性
DOI：
10.1002/2017jd027904
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
X. Bian
中科院分区：
文献类型：
--
作者：
Michael T. Kiefer;S. Zhong;W. Heilman;J. Charney;X. Bian
更好地了解荒地火灾期间森林内部和上方的大气扰动与荒地火灾的许多方面相关，包括火势蔓延、烟雾输送和扩散以及树木死亡率。在本研究中，ARPS-CANOPY 模型是带有冠层参数化的高级区域预测系统 (ARPS) 模型的一个版本，用于一系列理想化数值实验，以研究垂直冠层结构对大气对地面固定感热通量（“火灾热通量”）响应的影响，其大小与低强度地表火灾的感热通量大致一致。五个垂直顶篷结构与五个火灾热通量大小相结合，产生一个包含 25 个模拟的矩阵。对火热通量扰动的风分量、垂直速度、动能和温度的分析表明，扰动的空间模式和幅度对垂直冠层结构敏感。随着火灾热通量的增加，垂直速度和动能都呈现出增加的趋势，对于有一定量的上层植被的情况比只有林下植被的情况更强。在只有林下植被的情况下，趋势较弱，表明当植被最集中在地表附近时，大气对地表火灾显热的响应会减弱。更一般地说，本研究提出的结果表明，将在一种森林中进行的火与大气相互作用研究的结果应用于具有不同树冠结构的其他森林时，应考虑树冠形态。
An improved understanding of atmospheric perturbations within and above a forest during a wildland fire has relevance to many aspects of wildland fires including fire spread, smoke transport and dispersion, and tree mortality. In this study, the ARPS‐CANOPY model, a version of the Advanced Regional Prediction System (ARPS) model with a canopy parameterization, is utilized in a series of idealized numerical experiments to investigate the influence of vertical canopy structure on the atmospheric response to a stationary sensible heat flux at the ground (“fire heat flux”), broadly consistent in magnitude with the sensible heat flux from a low‐intensity surface fire. Five vertical canopy structures are combined with five fire heat flux magnitudes to yield a matrix of 25 simulations. Analyses of the fire‐heat‐flux‐perturbed u component of the wind, vertical velocity, kinetic energy, and temperature show that the spatial pattern and magnitude of the perturbations are sensitive to vertical canopy structure. Both vertical velocity and kinetic energy exhibit an increasing trend with increasing fire heat flux that is stronger for cases with some amount of overstory vegetation than cases with exclusively understory vegetation. A weaker trend in cases with exclusively understory vegetation indicates a damping of the atmospheric response to the sensible heat from a surface fire when vegetation is most concentrated near the surface. More generally, the results presented in this study suggest that canopy morphology should be considered when applying the results of a fire‐atmosphere interaction study conducted in one type of forest to other forests with different canopy structures.
通过 FireFlux 实验的现场观察评估 WRF-SFIRE 性能
影响因子：
5.1
作者：
Kochanski, A. K.;Jenkins, M. A.;Mandel, J.;Beezley, J. D.;Clements, C. B.;Krueger, S.
通讯作者：
Krueger, S.