Comparing geostationary and polar-orbiting satellite sensor estimates of Fire Radiative Power (FRP) during the Black Summer Fires (2019-2020) in south-eastern Australia

Abstract

Background: We compared estimates of Fire Radiative Power (FRP) from sensors onboard geostationary Himawari-8 (BRIGHT_AHI) and polar-orbiting TERRA/AQUA (MOD14/MYD14) satellites during the 2019/2020 Black Summer Fires in South-Eastern Australia. Aim/methods: Analysis was performed on a pixel, bioregion, and wildfire event basis to assess the utility of the new BRIGHT_AHI FRP product. Key results: Results show a high agreement between the products (r = 0.74, P < 0.01) on a pixel level, with BRIGHT_AHI generally underestimating FRP compared to MOD14/MYD14. Regional spatiotemporal trends were captured in more detail by BRIGHT_AHI due to its higher temporal resolution, with MOD14/MYD14 systematically underestimating the total and sub-diurnal FRP values. Nevertheless, both datasets captured similar fire ignition and spread patterns for the study region. On the event level, the correlation between the datasets was moderate (r = 0.49, r = 0.67), when considering different temporal constraints for hotspot matching. Conclusions: The results of this study indicate that BRIGHT_AHI approximates the well-established MOD14/MYD14 product during concurrent observations, while revealing additional temporal information for FRP trends. Implications: This gives confidence in the reliability of BRIGHT_AHI FRP estimates, opening the way for a denser observation record (10-min intervals) that will provide new opportunities for fire activity reporting, some of which are presented here.