Fig. 2 | Nature Communications

Fig. 2

From: 21st-century modeled permafrost carbon emissions accelerated by abrupt thaw beneath lakes

Fig. 2

Comparison of gradual, top-down thaw in upland permafrost and abrupt thaw beneath lakes. a Schematic. b Field measurements of net ecosystem exchange (NEE) in Greenland (#1,2)28, Healy, Alaska (#3–5)26, western Alaska (#6–9), interior Alaska (#10,11,14–19) and northeast Siberia (#12,13); standard error bars. c Radiocarbon-dated CO2 from gradual thaw NEE26,28 (green), including specifically the old soil carbon component27 (brown). Radiocarbon-dated CO2 in ebullition bubbles of new abrupt thaw lakes formed since 1949 (blue, open diamonds). Also in c, abrupt thaw CH4 emitted as bubbles from expanding lake margins21 (blue filled squares) and new lakes (blue open squares). In c, standard errors of the mean are shown for n ≤ 27 individually dated ebullition events per lake on 11 lakes (Supplementary Data 2). NEE and radiocarbon ages associated with abrupt thaw were higher than those of gradual thaw (Kolmogorov-Smirnov test, p < 0.001)