biogeochemical cycle
; biomass burning
; black carbon
; carbon flux
; combustion
; dissolved organic carbon
; fossil fuel
; particulate matter
; particulate organic matter
; transport process
; China
; Yangtze River
; Yellow River
英文摘要:
Major rivers play important roles in transporting large amounts of terrestrial organic matter from land to the ocean each year, and the organic matter carried by rivers contains a significant fraction of black carbon (BC). A recent study estimated that 0.027 Gt of BC is transported in the dissolved phase by rivers each year, which accounts for ~10% of the global flux of dissolved organic carbon. The relative sources of this large amount of riverine dissolved black carbon (DBC) from biomass burning (young, modern 14C) and fossil fuel (old, 14C free) combustion are not known. We present radiocarbon measurements of BC in both dissolved and particulate phases transported by the Changjiang and Huanghe Rivers, the two largest rivers in China, during 2015. We show that two, distinct BC pools (young and old) were carried by the rivers. The DBC pool was much younger than the particulate BC (PBC) pool. Mass balance calculations indicate that most (78–85%) of the DBC in the Changjiang and Huanghe Rivers was derived from biomass burning, and only 15–22% was from fossil fuel combustion. In contrast, PBC from biomass burning and fossil fuel combustion were approximately equal in these two rivers. Export of PBC and DBC by the rivers are decoupled, and fluxes of PBC were 4.1 and 6.7 times higher than DBC in the Changjiang and Huanghe Rivers, respectively. The 14C age differences of the two BC pools suggest that BC derived from biomass burning and fossil fuel combustion are mobilized in different phases and on different time scales in these rivers. �2016. American Geophysical Union. All Rights Reserved.
Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, China; Qingdao Collaborative Innovation Center of Marine Science and Technology, Qingdao, China; Department of Earth System Science, University of California, Irvine, CA, United States
Recommended Citation:
Wang X,, Xu C,, Druffel E,et al. Two black carbon pools transported by the Changjiang and Huanghe Rivers in China[J]. Global Biogeochemical Cycles,2016-01-01,30(12)