Petagram‐Scale Dissolved Organic Carbon Stocks in Alaskan Permafrost Soils

Abstract The pan‐Arctic permafrost region hosts vast amounts of soil organic carbon, a pool increasingly susceptible to climate‐driven changes. Dissolved organic carbon (DOC) is a key component of this carbon pool. However, its stocks and fluxes remain poorly understood due to limited measurements and challenges of tracking subsurface fluxes across landscapes. Through continuous leaching experiments on Alaskan soil samples, we established a statistical relationship between the percentage of leached soil carbon as DOC (DOC yield) and soil total organic carbon content (TOC) ( y = 5.11× −0.43 , R 2 = 0.59). After validating this relationship against literature data, we applied it to estimate effective permafrost soil DOC stocks in Alaska, yielding 1.72 (1.01−2.66) Pg C for the 0–3 m depth interval and 0.53 (0.24−1.00) Pg C for the active layer. Our results highlight the importance of the permafrost soil DOC pool, and the robust quantification method offers insights for future pan‐Arctic DOC release assessments.