High-resolution simulations unravel intensification mechanisms of pyrocumulonimbus clouds

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Bibliographic Details
Main Authors:	Wang, Qing, Gazen, Cenk, Ihme, Matthias, Carver, Robert, Parker, Jeffrey B., Schneider, Tapio, Chammas, Sheide, Chen, Yi-Fan, Anderson, John
Format:	Preprint
Published:	2025
Subjects:	Atmospheric and Oceanic Physics Computational Physics Fluid Dynamics
Online Access:	Acceder al recurso
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author	Wang, Qing Gazen, Cenk Ihme, Matthias Carver, Robert Parker, Jeffrey B. Schneider, Tapio Chammas, Sheide Chen, Yi-Fan Anderson, John
author_facet	Wang, Qing Gazen, Cenk Ihme, Matthias Carver, Robert Parker, Jeffrey B. Schneider, Tapio Chammas, Sheide Chen, Yi-Fan Anderson, John
contents	Pyrocumulonimbus (pyroCb) firestorms -- wildfire-generated thunderstorms -- can trigger rapid fire spread. However, the multi-physics nature of pyroCb has made their core mechanisms inaccessible to direct observation and previous simulation and prediction efforts. We introduce a new simulation capability with the first high-resolution, fully coupled simulations of a pyroCb, allowing us to unravel its life cycle governed by two opposing mechanisms. We show fuel moisture is an energy sink that attenuates fire intensity rather than fueling clouds, resolving a long-standing debate. Conversely, we identify the driver of rapid intensification: the Self-Amplifying Fire-Induced Recirculation (SAFIR) mechanism, where precipitation-induced downdrafts intensify the parent fire under weak winds. This work provides a new mechanistic framework for pyroCb prediction and demonstrates a transformative computational approach for previously intractable problems in environmental science.
format	Preprint
id	arxiv_https___arxiv_org_abs_2507_01237
institution	arXiv
publishDate	2025
record_format	arxiv
spellingShingle	High-resolution simulations unravel intensification mechanisms of pyrocumulonimbus clouds Wang, Qing Gazen, Cenk Ihme, Matthias Carver, Robert Parker, Jeffrey B. Schneider, Tapio Chammas, Sheide Chen, Yi-Fan Anderson, John Atmospheric and Oceanic Physics Computational Physics Fluid Dynamics Pyrocumulonimbus (pyroCb) firestorms -- wildfire-generated thunderstorms -- can trigger rapid fire spread. However, the multi-physics nature of pyroCb has made their core mechanisms inaccessible to direct observation and previous simulation and prediction efforts. We introduce a new simulation capability with the first high-resolution, fully coupled simulations of a pyroCb, allowing us to unravel its life cycle governed by two opposing mechanisms. We show fuel moisture is an energy sink that attenuates fire intensity rather than fueling clouds, resolving a long-standing debate. Conversely, we identify the driver of rapid intensification: the Self-Amplifying Fire-Induced Recirculation (SAFIR) mechanism, where precipitation-induced downdrafts intensify the parent fire under weak winds. This work provides a new mechanistic framework for pyroCb prediction and demonstrates a transformative computational approach for previously intractable problems in environmental science.
title	High-resolution simulations unravel intensification mechanisms of pyrocumulonimbus clouds
topic	Atmospheric and Oceanic Physics Computational Physics Fluid Dynamics
url	https://arxiv.org/abs/2507.01237

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