Upper Atmosphere Smoke Injection from Large Areal Fires

TL;DR

This study uses advanced fire simulations to analyze how local weather conditions like wind, humidity, and atmospheric stability influence smoke injection into the upper atmosphere from large fires.

Contribution

It introduces a detailed modeling approach to quantify the effects of environmental factors on smoke lofting from large areal fires.

Findings

Moisture significantly increases smoke lofting altitude.

Higher wind speeds reduce smoke injection height.

Stable atmospheric conditions inhibit plume rise.

Abstract

Large fires can inject smoke into the upper troposphere and lower stratosphere. Detailed fire simulations allow for assessment of how local weather interacts with these fires and affects smoke lofting. In this study, we employ the fire simulation package in the Weather Research and Forecasting model (WRF-Fire), Version 4.0.1, to explore how smoke lofting from a fire burning a homogeneous fuel bed changes with varying local winds, relative humidity, and atmospheric boundary-layer stability for two different-sized areal fires. We find that the presence of moisture has the greatest influence on the results by raising the altitude of lofting, while faster winds speeds dampen lofting and lower the injection height. Stably stratified conditions further inhibit plume propagation compared with neutrally stratified conditions.