Fig. 5: Fire weather reconstruction from the Law Dome summer sea salt (LDsss) aerosol concentration record compared to local palaeoclimate records.

a Observed FFDI (Dowdy et al.²⁸) and 2000+ year (1-2016 CE) FFDI mean reconstruction over the forested east coast and alpine regions of southeast Australia using the LDsss record (hatched area in map inset (g)). Light grey shading represents 95% prediction interval of the FFDI mean reconstruction. The long-term signal is represented as a 30-year loess filter of the NDJF seasonal mean for observations (dark red; the dashed line includes data to 2019/20 season, the solid line includes data to 2015/16 season) and FFDI mean prediction using LDsss (black). Red circles indicate potential analogue seasons where the upper estimate (95% prediction interval) of the reconstruction exceeded the observed FFDI over the 2019/20 season. b Number of seasons over an 11-year period with NDJF seasonal FFDI observations and prediction > 1960-1990 mean (7.13). Red squares indicate potential analogue periods of increased decadal frequency of above-average fire weather. c Reconstructed maximum temperature from Yarrangobilly Caves (McGowan et al.⁴⁴) and mean summer temperature from Club Lake (Thomas et al.⁴⁵). Approximate age model dating error for Club Lake indicated by horizontal lines d Charcoal (>250 μm) accumulation rate from Club Lake (Thomas et al.⁴⁵). Approximate age model dating error indicated by horizontal lines. e Warm season (October–March) rainfall reconstruction for East Coast and Southern Slopes NRM regions (Freund et al.⁴¹). f Austral summer (DJF) Palmer Drought Severity Index (PDSI) area average reconstruction (Palmer et al.⁶⁸) over the FFDI reconstruction region. g Map of eastern Australia including the FFDI reconstruction area, 2019/20 burnt area, local proxy records, and NRM rainfall reconstruction regions.