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CO 2 uptake in the East China Sea relying on Changjiang runoff is prone to change
Author(s) -
Tseng ChunMao,
Liu K.K.,
Gong G.C.,
Shen P.Y.,
Cai W.J.
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl049774
Subject(s) - china sea , surface runoff , china , environmental science , geology , climate change , oceanography , hydrology (agriculture) , geography , archaeology , geotechnical engineering , ecology , biology
Limited knowledge exists concerning the unusually large CO 2 uptake capacity in the East China Sea (ECS), which is the eminent continental shelf pump for efficient transfer of atmospheric CO 2 to the deep ocean. Here we show evidence of strong control of river runoff on the CO 2 uptake capacity of the ECS. From 8‐years of observations in the productive ECS shelf, we present the first dataset to show the complete seasonal cycle of CO 2 flux, which gives an annual flux of 2.3 ± 0.4 mol C m −2 y −1 as a net sink of atmospheric CO 2 . Further, we found biological sequestration of CO 2 taking place in the highly productive Changjiang river plume in warm seasons due to the riverine nutrient enrichment. Consequently, changes in the plume area due to changes in the Changjiang River Discharge (referred to as the Discharge hereafter) strongly affect the CO 2 uptake capacity. As the Discharge may decrease due to the Three Gorges Dam operation, the Changjiang plume will probably also decrease, resulting in reduction in CO 2 uptake capacity and even a shift from a CO 2 sink to a source.