In this section
@article{Huang:2016:10.1016/j.scitotenv.2016.02.201,
author = {Huang, X and Rein, G},
doi = {10.1016/j.scitotenv.2016.02.201},
journal = {Science of the Total Environment},
pages = {1440--1446},
title = {Interactions of Earth's atmospheric oxygen and fuel moisture in smouldering wildfires},
url = {http://dx.doi.org/10.1016/j.scitotenv.2016.02.201},
volume = {572},
year = {2016}
}
TY - JOUR
AB - Vegetation, wildfire and atmospheric oxygen on Earth have changed throughout geological times, and are dependent on each other, determining the evolution of ecosystems, the carbon cycle, and the climate, as found in the fossil record. Previous work in the literature has only studied flaming wildfires, but smouldering is the most persistent type of fire phenomena, consuming large amounts of biomass. In this study, the dependence of smouldering fires in peatlands, the largest wildfires on Earth, with atmospheric oxygen is investigated. A physics-based computational model of reactive porous media for peat fires, which has been previously validated against experiments, is used. Simulations are conducted for wide ranges of atmospheric oxygen concentrations and fuel moisture contents to find thresholds for ignition and extinction. Results show that the predicted rate of spread increases in oxygen-rich atmospheres, while it decreases over wetter fuels. A novel nonlinear relationship between critical oxygen and critical moisture is found. More importantly, we show that compared to previous work on flaming fires, smouldering fires can be ignited and sustained at substantially higher moisture contents (up to 100% MC vs. 40% for 21% oxygen level), and lower oxygen concentrations (down to 13% vs. 16%). This defines a new atmospheric oxygen threshold for wildfires (13%), even lower than previously thought in Earth Sciences (16%). This finding should lead to reinterpretation of how the char remains observed in the fossil record constrain the lower concentration of oxygen in Earth's atmosphere in geological timescale.
AU - Huang,X
AU - Rein,G
DO - 10.1016/j.scitotenv.2016.02.201
EP - 1446
PY - 2016///
SN - 0048-9697
SP - 1440
TI - Interactions of Earth's atmospheric oxygen and fuel moisture in smouldering wildfires
T2 - Science of the Total Environment
UR - http://dx.doi.org/10.1016/j.scitotenv.2016.02.201
UR - http://hdl.handle.net/10044/1/53140
VL - 572
ER -
Phone:
+44 (0)20 7594 7036
Email:
g.rein@imperial.ac.uk
Address:
Department of Mechanical Engineering,
City & Guilds Building,
South Kensington Campus, London, SW7 2AZ, UK