资源环境科技发展态势分析平台

Research in the pursuit of better understanding of fire behavior and fire-atmosphere interaction has frequently encountered a dearth of observational data, especially from events that cause most impact. Here we show that meteorological radar has been demonstrated as an effective tool for profiling the microphysics, thermodynamics, and fire behavior feedback of wildfire plumes, including for cases with deep and moist convection occurring in the fire plume. A synthesis of knowledge on the use of radar for the analysis of wildfire is presented, and the new term pyrometeor is introduced to describe the range of scatterers observed by radar, the reflectivity signature of which is determined by interacting processes of wildfire behavior and atmospheric convection. The reflectivity theories of pyrometeors are compared, and it is shown that there are gaps in knowledge on the size distributions of pyrometeors as well as the complex dielectrics. Observational case studies are compared across plume microphysics, plume thermodynamics and deep pyroconvection, and operational usage of radar to monitor wildfire. The dominant hypothesis of reflectivity is scattering from ash particles, though theories for scattering such as from larger debris exist, although evidence is limited for any hypothesis. Vortices have also been identified using Doppler velocity radar data, but there is limited understanding of their cause and influence on fire-atmosphere interactions. Recommendations are provided for methods and data sets to advance the application of radar for observing and understanding wildfires, including for plume microphysics and atmosphere-fire interactions.

Plain Language Summary This literature review covers the theory, laboratory, and observational uses of radar in the study of wildfires, providing the necessary background on what and how radar observes wildfire plumes and associated atmospheric processes. The understanding of theory alongside what has been observed can inform decision makers and future scientific study to better interpret weather radar observations of wildfire plumes and meteorology. It is intended that this will lead to an improved ability to prepare for, and manage, the hazards associated with wildfires.