1,2,1,5- 1Lawrence Livermore National Laboratory, Livermore, CA, United States of America (tang30@llnl.gov)
- 2Desert Research Institute, Reno, NV, USA
- 3Department of Earth System Science, University of California, Irvine, CA, USA
- 4Princeton University, Princeton, NJ, USA
- 5Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA
Extreme wildfires have become more frequent in many regions worldwide in recent years. Compared with moderate events, the most intense wildfires, especially those that generate pyrocumulonimbus (pyroCb) clouds, exert disproportionately large impacts on the Earth system and cause substantial socioeconomic losses. High‑fidelity modeling is a critical tool for studying wildfire behavior, identifying key drivers, and quantifying their impacts. Here, we improve the pyroCb representation in the global Energy Exascale Earth System Model (E3SM) by leveraging its kilometer-scale regionally refined model (RRM) capability, integrating satellite-based high-resolution (hourly, 500 m) fire emissions, and incorporating fire-related parameterizations. Compared with conventional global simulations at coarse resolution (approximately 100 km), the kilometer-scale grid spacing over the fire source region substantially improves the simulation by explicitly resolving more fire-related dynamic and thermodynamic processes. In the meanwhile, the RRM configuration enables seamless smoke transport and interactions between the fine and coarse meshes and allows efficient simulation of downstream fire aerosol spatiotemporal distributions in regions where high resolution is less critical. The simulations capture essential pyroCb features, e.g., cloud height, spatiotemporal evolution, and convective intensity, as observed by satellite and ground measurements for different cases occurred in California. Sensitivity experiments suggest that pyroCb formation in our simulations is not controlled by a single dominant factor, but instead emerges from the coupled interactions of multiple fire-atmosphere processes. Furthermore, we use the global RRM to investigate the mechanisms of stratospheric aerosol injection and examine implications for seasonal and longer predictability. Because these simulations include interactive chemistry and aerosol schemes, we also evaluate the impacts of wildfires on surface air quality.
How to cite: Tang, Q., Ke, Z., Zhang, J., Chen, Y., Ding, X., Randerson, J., Zhang, Y., and Chen, G.: Extreme wildfire simulations using kilometer-scale regionally refined E3SM, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8792, https://doi.org/10.5194/egusphere-egu26-8792, 2026.
