Fig. 1: Temporal variations of the summer fire weather index (FWI) over eastern Siberia and sea-ice concentration (SIC) anomaly over the Russian Arctic during 1979–2021 and their linear trend patterns over 1979–2003 and 2004–2021.
From: Rapid summer Russian Arctic sea-ice loss enhances the risk of recent Eastern Siberian wildfires
a, b Normalized time series of summer (June–August, JJA) mean (a) fire weather index (FWI, unit: non-dimensional) anomaly averaged over eastern Siberia (90o–150oE, 60o–75oN) and (b) JJA-mean sea-ice concentration (SIC, unit: %) anomaly averaged over the Russian Arctic region (30o–130oE; 65o–85oN) during 1979–2021, where the dashed blue (red) line represents the linear trends of the FWI and SIC over 1979–2003 (2004–2021) with the slope rates of \(-0.29\) and \(-0.08\) (1.18 and \(-1.04\)) standard deviations (STDs) per decade. c–f Linear trend patterns of JJA-mean c, e FWI (color shading, unit: non-dimensional value per decade) and d, f SIC (color shading, unit: % per decade) anomalies over c, d 1979–2003 and e, f 2004–2021. The black box denotes the eastern Siberia (90o–150oE, 60o–75oN). The dotted regions represent that the linear trends are statistically significant (p < 0.05) for the Mann–Kendall test.
