1 2 A revised pan-Arctic permafrost soil Hg pool, based on western Siberia peat Hg 3 and carbon observations 4 5 Artem G. LIM1, MARTIN JISKRA2, Jeroen E. SONKE3, 6 Sergey V. LOIKO1, NATALIA KOSYKH4, Oleg S. POKROVSKY3,5* 7 8 1 BIO-GEO-CLIM Laboratory, Tomsk State University, Tomsk, Russia 9 2 University of Basel, Environmental Geosciences, Bernoullistrasse 30, 4056 Basel, Switzerland 10 3 Geosciences and Environment Toulouse, UMR 5563 CNRS, 14 Avenue Edouard Belin 31400 11 Toulouse, France 12 4 Lab Biogeocenol, Inst Soil Science & Agrochem, Russian Acad Sci, Siberian Branch, 13 Novosibirsk, Russia 14 5 N. Laverov Federal Center for Integrated Arctic Research, Russian Academy of Sciences, 15 Arkhangelsk, Russia 16 17 *Email:
[email protected] 18 19 Key words: mercury, peat soil, landscape, bog, forest, thaw, Siberia 20 21 22 Submitted to Biogeosciences, after revision, April 29, 2020 23 24 25 26 27 1 28 Abstract 29 Natural and anthropogenic mercury (Hg) emissions are sequestered in terrestrial soils over short, 30 annual, to long, millennial time scales, before Hg mobilization and run-off impacts wetland and 31 coastal ocean ecosystems. Recent studies have used Hg to carbon (C) ratios, RHgC, measured in 32 Alaskan permafrost mineral and peat soils, together with a northern circumpolar permafrost soil 33 carbon inventory, to estimate that these soils contain large amounts, 184 to 755 Gg of Hg in the 34 upper 1 m. However, measurements of RHgC on Siberian permafrost peatlands are largely 35 missing, leaving the size of estimated northern soil Hg budget, and its fate under Arctic warming 36 scenarios uncertain.