Development of a REgion‐Specific ecosystem feedback fire (RESFire) model in the Community Earth System Model
Fires play a critical role in modulating regional and global climate through disturbances on meteorological, biogeochemical, and hydrological processes, while fires are strongly affected by climate, terrestrial ecosystems, and human activities. The complex climate‐fire‐ecosystem interactions with anthropogenic disturbance are not well understood. We developed a REgion‐Specific ecosystem feedback Fire (RESFire) model in the Community Earth System Model (CESM) that provides modeling capability to reproduce the observed burning patterns and trends and to understand fire related climatic processes. Comparing with the default Community Land Model version 4.5 fire model in CESM, the RESFire model includes heterogeneous natural and anthropogenic constraints on fire ignition and spread, improved fire impact parameterization including online fire emissions and fire induced land cover changes, and modeling bias corrections for online fire weather simulation. Evaluation results based on the International Land Model Benchmarking package show significant improvements in fire simulation performance. The overall modeling score of burned area simulation increases from 0.50 with Community Land Model version 4.5 to 0.62 (RESFire driven by the observation‐reanalysis data) and 0.60 (RESFire driven by the bias‐corrected Community Atmosphere Model version 5 simulation). The attribution analysis of decadal burned area trends suggests distinct contributions of natural and anthropogenic forcing in different regions, which are consistent with previous observations. The model also includes a fire impact module for estimating atmospheric responses to fire emissions as well as fire disturbances on ecosystems, land cover, and surface radiation budget. These results demonstrate the latest progress of global fire model development that enables fully interactive climate‐fire‐ecosystem studies using CESM.