SIVAJI-Patra1，2, LIU Cong-qiang1, LI Si-liang1, WANG Bao-li1, WANG Qi-lian1
(1.State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China；
2. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China)
Abstract: Water samples collected along the Changjiang River estuary in June 2005 were studied for their dissolved inorganic carbon (DIC) contents and their isotopic composition. We found that CO2 super-saturation significantly occurred in the riverine zone and decreased sharply in the coastal zone. The δ13CDIC values are within the range of -10.0‰ and -0.9‰, and vary along the salinity gradient. The deviation of observed DIC concentrations and δ13 CDIC from the mixing equation between riverine and marine water indicates multiple processes controlling the carbon cycling in different zones. Degassing of CO2 mainly occurred in the riverine zone, photosynthesis in the estuary zone and carbonate mineral precipitation in the coastal zone.
Key words: the Changjiang River; estuary; dissolved inorganic carbon; isotope; CO2
EARTH AND ENVIRONMENT Vol. 38, No.4, Tot No.282, 2010, Page 409-413
