Numerical simulations of grassland fires in the Northern Territory, Australia: A new subgrid-scale fire parameterization
Numerical simulations of grassland fires in the Northern Territory, Australia: A new subgrid-scale fire parameterization
复制标题
澳大利亚北领地草原火灾的数值模拟：一种新的亚网格尺度火灾参数化
DOI：
10.1029/2002jd003340
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发表时间：
2003
影响因子：
--
通讯作者：
D. Latham
中科院分区：
文献类型：
--
作者：
T. Clark;Morwenna Griffiths;M. Reeder;D. Latham
[1]发展了一种新的次网格尺度的参数化，将野火的影响纳入大气的数值模式中。该参数是根据燃烧材料的温度和未燃烧的机载燃料的浓度编写的。参数化所依据的两个中心假设。首先，氧进入燃烧区域的传输限制了氧化的速度，用固定时间标度的瑞利混合来表示。其次，燃烧气体和大气被视为单独的流体。为简单起见，本文特意不考虑燃烧流体与大气之间的传导效应。这意味着网格尺度的浮力被定义为燃烧流体和周围大气的浮力的体积平均值，而火灾引起的浮力仅限于含有燃烧气体的区域。这些假设导致了一个高度简化的系统来捕捉燃烧过程的本质。该参数化被用于模拟观察到的北领地(澳大利亚)的一场草地火灾。
[1] A new subgrid-scale parameterization is developed to incorporate the effects of wild fires into a numerical model of the atmosphere. The parameterization is written in terms of the temperature of the combusting material and the concentration of the unburned airborne fuel. There are two central assumptions on which the parameterization rests. First, the transport of oxygen into the region of combustion, which limits the rate of oxidation, is represented by Rayleigh mixing with a fixed timescale. Second, the combusting gases and the atmosphere are treated as separate fluids. For simplicity, the effects of conduction between the combusting fluid and the atmosphere are purposely not considered in this paper. This means that the grid-scale buoyancy is defined as a volume average of the buoyancy of the combusting fluid and the ambient atmosphere, and that fire-induced buoyancy is confined to the region containing the combusting gases. These assumptions lead to a highly simplified system capturing the essence of the combustion process. The parameterization is used in a simulation of an observed grass fire in the Northern Territory (Australia).