2020 Annual Meeting of the APS Four Corners Section (Virtual)
Volume 65, Number 16
Friday–Saturday, October 23–24, 2020;
Albuquerque, NM (Virtual)
Session D01: Plenary Talks II
12:30 PM–1:40 PM,
Friday, October 23, 2020
Chair: David Dunlap, UNM
Abstract: D01.00001 : The interaction between wildland fire and their surroundings through fluid dynamics
12:30 PM–1:05 PM
Live
Preview Abstract
Abstract
Author:
Rod Linn
(Los Alamos National Laboratories)
Wildfires pose a threat to life, property and critical infrastructure, but
wildland fire is an unavoidable part of the natural environment.~ In order
to improve our ability to cope with wildfires and anticipate their impacts
on the earth system it is important to understand the processes that drive
them and the mechanisms through which they are influenced by their
surrounding environment.~ The motion of the atmosphere surrounding a fire
and the two-way interactions between fires and the atmosphere play critical
roles in fire behavior.~ These motions are influenced by the vegetation
structure and nearby topography as well as ambient wind conditions as well
as the fire itself.~ The influences of topography on fire behavior are
dominated by terrain-induced changes in entrainment patterns that control
the patterns of heat transfer to unburned fuel.~ Multi-scale two-way
fire/atmosphere feedbacks determine heterogenous fireline dynamics and thus
fire spread, the effects of fires on ecology and the near-field lofting and
transport of the smoke and fire brands (lofted burning material, which can
be transported downwind and start new fires). The fluid motions surrounding
a fire influence the effectiveness and consequences of fuels management
activities.~ For example, forest thinning not only removes combustible fuel,
but also changes the vegetation drag and thus the ventilation of the fire,
which can potentially increase fire spread.~ The importance of the coupled
fire/atmosphere fluid motion surrounding fire is especially important in the
context of prescribed fires.~ Safe use of prescribed fires to reduce fire
risk while accomplishing ecologic objectives typically depends on fire
practitioner's ability to anticipate the interaction of multiple fires.~
This interaction is tied to the interaction between the fires through their
fire-induced indrafts.
Recent advancements in computing power have created new opportunity for the
complimentary use of numerical models to provide additional perspectives
concerning fire/atmosphere feedbacks that have previously been challenging
to explore.~ A better understanding of the way fluid motions of the local
atmosphere influence fire will improve our ability to anticipate fire
behaviour and develop effective fire and fuels management strategies.