Publication Date

Spring 2023

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Meteorology and Climate Science

Advisor

Adam Kochanski

Keywords

Creek Fire, fire-induced circulations, plume-dominated, Thomas Fire, wind-driven, WRF-SFIRE

Subject Areas

Meteorology

Abstract

For this study, fire-induced winds from a wind-driven fire (Thomas Fire) and a plume dominated fire (Creek Fire) were analyzed. Then, the small-scale fire-induced circulations within steep canyons were examined. This study used two different WRF-SFIRE simulations, one without the fire present, and the other with fire. The fire-induced conditions were calculated by subtracting a given variable from the “No Fire Run” from the “Fire Run” (Fire - No Fire). Wind speed and geopotential height fields were analyzed to assess spatial and temporal variability. Furthermore, cloud water mixing ratio, precipitation, and fuel moisture were analyzed for the Creek Fire to assess fire-induced rainfall. When analyzing steep canyons, wind speed, temperature, and pressure were analyzed under two different wind profiles, one at a constant 5 m/s, and another with increasing speed and wind shear with height. It was found that the Thomas Fire generally produced much stronger winds than the Creek Fire. The Creek Fire wind speeds followed the diurnal cycle while the Thomas Fire did not. Additionally, intense geopotential height perturbations over the Creek Fire were due to thunderstorms which reduced fire rate of spread. In terms of steep canyons, many observations were found to be like the Creek Fire. In addition, the higher canyons produced more intense fire-induced circulations, particularly with pressure and wind speed. Furthermore, fire rate of spread increased rapidly in steeper canyons upon reaching canyon walls and became explosive in nature.

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