GEOL 2207 Lecture Notes - Pyrolysis, Lightning
Document Summary
Ignitors: lightning, volcanic activity, human action (any source of sufficient heat) Ignition: begins at ~300 degrees celcius for wood, pyrolysis release flammable gases, flames are generated, does not always lead to wildfires, depends on availability of fuel, not a single event, ongoing as wildfire moves. Occuring again and again as it moves along. Flaming combustion: early phase of fire, high t, flames (gas release from pyrolysis), large amount of unburned material. Smoldering combustion: lower t, does not require pyrolysis for growth, consumption of wood without flames. Similar to camp fire, no flames but heat still being released. Transfer occurs as conduction, convection and radiation. Radiation heat increases surface temperature of fuel. Rising gases remove heat and combustion products from zone of flaming. Pulls in fresh air to sustain combustion. Certain forest types that are really prone to wildfires. Have a lot to do with how much oils and resins in the bark, coniferous.
