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Satellite‐based active fire data are a viable tool to understand the role of global fires in the biosphere and atmosphere. The Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on Aqua and Terra satellites are nearing the end of their lives. The Visible Infrared Imaging Radiometer Suite (VIIRS) sensor on the Suomi National Polar‐orbiting Partnership satellite and the subsequent Joint Polar Satellite System series is expected to extend the MODIS active fire record. Thus, understanding the similarities of and discrepancies between the two data sets during their overlap period is important for existing applications. This study investigated the dependence of the MODIS and VIIRS fire characterization capabilities on satellite view zenith angle and the relationship between the two sensors' fire radiative power (FRP) from individual fire clusters to fire data on continental and global scales. The results indicate that the VIIRS fire characterization capability is similar across swath, whereas MODIS is strongly dependent on view zenith angle. Statistical analyses reveal that the VIIRS and MODIS FRP relationship varies between different spatial scales. In fire clusters, MODIS and VIIRS FRP estimates are very comparable, except for large boreal forest fires where VIIRS FRP is approximately 47% smaller. At the continental scale, the contemporaneous FRP retrievals from MODIS and VIIRS are generally comparable and strongly correlated, but VIIRS FRP is slightly larger and their differences vary across seasons. At global 1° × 1° grids, the FRP difference between the two sensors is, on average, approximately 20% in fire‐prone regions but varies significantly in fire‐limited regions.

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Smoke aerosols released from biomass burning greatly influence air quality, weather, and climate. The total particulate matter (TPM) of smoke aerosols has been demonstrated to be a linear function of fire radiative energy (FRE) during a period of biomass burning via a smoke aerosol emission coefficient (Ce). However, it remains challenging to quantify Ce appropriately through satellite observations. In this study, an innovative approach was put forward to explore Ce by establishing the relationships between FRE and TPM in two regions, the CONtiguous United States and Indonesia. Specifically, we identified 584 isolated fire clusters and smoke plumes in the CONtiguous United States and 248 in Indonesia using Moderate Resolution Imaging Spectroradiometer natural color images, and then calculated FRE from Moderate Resolution Imaging Spectroradiometer active fire product and TPM from Moderate Resolution Imaging Spectroradiometer aerosol optical depth product for each fire‐smoke matchup during Terra and Aqua overpasses. The relationships between TPM and FRE were constructed to determine Ce using an ordinary least squares regression. The results show that FRE and TPM are significantly correlated (r2 ≥ 0.63, p < 0.001) with the Ce varying across regions and fuel types. In the CONtiguous United States, forest Ce values are 21.3 and 34.1 g/MJ and savanna Ce values are 18.2 and 22.8 g/MJ for western and eastern regions, respectively; additionally, Ce is 20.9 g/MJ for grasslands and 5.0 g/MJ for shrublands. In Indonesia, Ce is 52.4 and 30.0 g/MJ for peatlands and forests, respectively. Overall, this study improves our understanding of Ce variations with fuel types and climate regions.

Biomass burning substantially contributes to atmospheric aerosol and greenhouse gas emissions that influence climate and air quality. Fire radiative energy (FRE) (units: MJ) has been demonstrated to be linearly related to biomass consumption (units: kg) with potential for improving biomass burning emission estimation. The scalar constant, termed herein as the FRE biomass combustion coefficient (FBCC) (units: kg/MJ), which converts FRE to biomass consumption, has been estimated using field and laboratory experiments, varying from 0.368 to 0.453 kg/MJ. However, quite different FBCC values, especially for satellite‐based approaches, have been reported. This study investigated the FBCC with respect to 445 wildfires that occurred from 2011 to 2012 across the Conterminous United States (CONUS) considering both polar‐orbiting and geostationary satellite data. The FBCC was derived by comparing satellite FRE estimates with biomass consumption for the CONUS. FRE was estimated using observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Geostationary Operational Environmental Satellite (GOES); biomass consumption was estimated using Landsat‐derived burned areas with fuel loadings from the Fuel Characteristic Classification System and using combustion completeness parameterized by Landsat burn severity and Fuel Characteristic Classification System fuelbed type. The reported results confirm the linearity of the empirical relationship between FRE and biomass consumption for wildfires. The CONUS FBCC was 0.374 kg/MJ for GOES FRE, 0.266 kg/MJ for MODIS FRE, and 0.320 kg/MJ considering both GOES and MODIS FRE. Limited sensitivity analyses, comparing MODIS and GOES FRE with biomass consumption estimated in three different ways, indicated that the FBCC varied from 0.301 to 0.458 kg/MJ.