# A 3D Numerical Model to Estimate Lightning Types for PyroCb Thundercloud
## 4 Conclusions  
The generation of lightning-ignited secondary wildfires is a serious issue for global firefighting management. This study presents a significant advancement in understanding the complex electrification phenomenon within pyroCb storms. By developing a 3D numerical model that incorporates the conceptual tripole charge configuration, this paper has investigated the electrical conditions under which +CG and \(-\)CG flashes are likely to occur. The proposed model emphasizes the role of the lower positive charge layer, and the influence of strong wind shear and high aerosol concentrations on the electrical characteristics of pyroCb thunderclouds is also explored. The results confirmed the initiation of a negative vertical field at the cloud base and a rise in thundercloud potential coupled with the expansion of a lower positive charge region. The proposed model has demonstrated that the wind shear extension of upper charge layers in thunderclouds can facilitate the incident of different lightning types during a pyroCb event, depending on the estimated value of initiation potential and surface charge density. The parametric study on aerosol concentration's effect also confirms the increased likelihood of both +CG and \(-\)CG lightning.  
The correlation between aerosol concentrations and charge density further highlights the sensitivity of pyroCb lightning to environmental conditions, drawing attention to the necessity of comprehensive monitoring and modeling in high aerosol conditions. This  
understanding is particularly valuable for predicting and mitigating the impact of lightning-induced spot fires, which intensify the severity and duration of wildfire events. This model forms the basis for identifying high-risk zones prone to lightning flashes in times of extreme weather conditions. This capability is crucial for enhancing early warning systems and improving firefighting strategies. Such a model can be adapted further to explore the interactions between lightning and wind energy infrastructure, providing a foundation for assessing the risks posed by charged particles to spinning wind turbines and other critical assets. Future research should aim to refine the model by incorporating real-time data and extending its application to other severe weather phenomena. Investigating the effects of corona discharge and lightning leaders in greater detail will further enhance the understanding of pyroCb electrification.  
Conceptualization, S.D.B. and A.K.; methodology, S.D.B.; software, S.D.B. and A.K.; validation, R.S., S.I. and A.K.; formal analysis, S.D.B.; investigation, S.D.B.; resources, S.D.B.; data curation, S.D.B.; writing--original draft preparation, S.D.B.; writing--review and editing, R.S., S.I. and A.K.; visualization, S.D.B.; supervision, R.S. and A.K.; project administration, A.K. and R.S. All authors have read and agreed to the published version of the manuscript.  
According to the acknowledgments, this research was funded by the Federation Univ. Australia and a Destination Australia scholarship.  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the authors on request.  
We gratefully acknowledge the financial support from the Centre of New Transition Research, Federation University Australia and the Destination Australia scholarship.  
The authors declare no conflicts of interest.  
The following abbreviations are used in this manuscript:  
\begin{tabular}{l l} PyroCb & Pyrocumulonimbus \\ CG & Cloud-to-ground \\ CCN & Cloud condensation nuclei \\ SC & Screening layer \\ UP & Upper positive \\ MN & Middle negative \\ LP & Lower positive \\ SOR & Successive over-relaxation \\ \end{tabular}