@article {270, title = {Pan-Arctic patterns in black carbon sources and fluvial discharges deduced from radiocarbon and PAH source apportionment markers in estuarine surface sediments}, journal = {Global Biogeochemical Cycles}, volume = {22}, year = {2008}, note = {id: 820; 307ZP Times Cited:3 Cited References Count:89Y}, abstract = {A pan-arctic geospatial picture of black carbon (BC) characteristics was obtained from the seven largest arctic rivers by combining with molecular combustion markers (polycyclic aromatic hydrocarbons) and radiocarbon (C-14) analysis. The results suggested that the contribution from modern biomass burning to BC ranged from low in the Yukon (8\%) and Lena (5\%) Rivers to high in the Yenisey River (88\%). The Mackenzie River contributed almost half of the total arctic fluvial BC export of 202 kton a(-1) (kton = 10(9) g), with the five Russian-Arctic rivers contributing 10-36 kton a(-1) each. The C-14-based source estimate of fluvially exported BC to the Arctic Ocean, weighted by the riverine BC fluxes, amount to about 20\% from vegetation/biofuel burning and 80\% from C-14-extinct sources such as fossil fuel combustion and relict BC in uplifted source rocks. Combining these pan-arctic data with available estimates of BC export from other rivers gave a revised estimate of global riverine BC export flux of 26 x 10(3) kton a(-1). This is twice higher than a single previous estimate and confirms that river export of BC is a more important pathway of BC to the oceans than direct atmospheric deposition.}, issn = {0886-6236}, doi = {10.1029/2007gb002994}, author = {Elmquist, M. and Semiletov, I. and Guo, L. D. and Gustafsson, O.} }