Development of a consistent global long-term burned area product (1982–2018) based on AVHRR-LTDR data

This paper presents the generation of a global long-term Burned Area (BA) product based on Advanced Very High Resolution Radiometer (AVHRR) images. The BA product was derived from the Land Long Term Data Record (LTDR), which provides a continuous dataset of geometrically and radiometrically corrected AVHRR images at 0.05° resolution (≈5 km). The BA algorithm improves a Beta version of this dataset (named FireCCILT10) previously released. The new version incorporates an enhanced Random Forest (RF) classification process based on two models, one using a global sample and another one using only Boreal regions. Solar zenith angle (SZA) corrections were introduced to mitigate the impact of satellite orbital drift. Binary classifications were obtained applying probability thresholds, and BA proportions were assigned to each burned pixel. The final product includes the date of detection at 0.05° resolution and the total burned area at 0.05° and 0.25° resolution, both covering the period from 1982 to 2018 (excluding 1994). The resulting product, called FireCCILT11, estimated that 165.26 Mkm² were globally burned between 1982 and 2018, with an annual average of 4.59 Mkm². The largest BA was found in 2011 with 5.18 Mkm² and the lowest was observed in 1991 with 4.09 Mkm². The month with the highest mean BA was August, with 0.63 Mkm², and the one with the lowest was March with 0.15 Mkm². Africa included 66% of total BA. Inter-comparison showed high correlation values with MODIS BA products for annual BA of the common years (r > 0.6, %MAE < 14%). Comparison with national fire statistics of Australia, Canada and Alaska showed also high correlation values (r > 0.8, %MAE < 42%).