Dissolved inorganic carbon and air-sea carbon exchange flux in the central and northern East China Sea in autumn
东海中北部海域秋季表层海水中无机碳与海气界面碳的迁移

Based on the comprehensive survey in the central and northern East China Sea near the Yangtze River estuary in November 2010, the distribution of the dissolved inorganic carbon system and air-sea exchange flux of carbon dioxide and its influencing factors were examined in this paper. High DIC was found in the northeast of the investigated area and Yangtze River estuary, whereas DIC content was small and changed gently in the south of the investigated area. The investigated area was mainly affected by the Kuroshio Branch Current which flows from the east part of Taiwan to northeast and Changjiang River Diluted Water. The pCO2 ranged from 40.8 ~ 63.5 Pa with an increasing trend from southeast area to northwest area along the KBCNT. ThepCO2 in the surface water negatively correlated with temperature and salinity, suggesting that with the increase of the temperature and salinity, the pCO2 decreased, and vice versa. In addition, according to calculation, the net sea-to-air CO2 exchange flux in autumn at each station was obtained. It varied from 2.69 to 33.66 mmol/(m2·d) with an average of (14.35 ± 7.06) mmol/(m2·d). The carbon flux near the Yangtze River Estuary was higher than that in the south part of the investigated area. Overall, the central and northern East China Sea emitted 2.35×104 ± 1.16×104 tons of carbon to the atmosphere per day which was a relatively strong source of atmospheric CO2 in autumn.