Evaluation of NOAA VIIRS and ABI Active Fire Products Through Comparisons With FIREX-AQ MASTER Field Campaign Data

The NOAA VIIRS (Visible Infrared Imaging Radiometer Suite) and ABI (Advanced Baseline Imager) Active Fire products are important for understanding and monitoring the impact of fires. Wildfires have indeed a strong impact on air quality and are an important indicator of climate change. However, assessing fire products can be difficult due to their sensitivity to different factors such as overlapping clouds or aerosols, observation time and pixel dimensions. Airborne campaigns provide crucial reference data for accurate assessments. We will report findings from the FIREX-AQ campaign carried out in summer 2019 by comparing the NOAA operational baseline VIIRS and ABI fire products, as well as sample data from Next Generation Fire System (NGFS), with data from the MODIS/ASTER Airborne Simulator (MASTER) instrument aboard a NASA DC-8 aircraft for fires over the central and western Conterminous United States (CONUS). Overall, both the VIIRS and ABI baseline products showed good performance in detecting active fires and estimating fire radiative power (FRP) under clear sky observing conditions. The percent difference for total FRP between VIIRS I-band Active Fire and MASTER ranged from -26% to 66% under clear sky observing conditions for Northwestern CONUS fire cases on 3 and 6 August 2019, with a mean of 32%. The new NOAA NGFS algorithm showed promise in detecting and analyzing fires in more challenging observing conditions, such as heavy smoke and clouds. Initial results for the Williams Flats fire case showed that the mean percent difference for total FRP between ABI baseline fires and MASTER was 104% compared to 45% for ABI NGFS and MASTER. The larger percent difference of total FRP between ABI baseline fires and MASTER was due to heavy smoke and cloud impacts at times, which limited the baseline fire detections. We will also show direct comparisons of NGFS product output to the baseline NOAA VIIRS and ABI fire products for some fire cases under both clear and cloudy sky observing conditions.