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

基于2010 年11 月对长江口外东海中北部海域的综合调查, 系统研究了该海域的无机碳体系参数的分布特征、海?气界面二氧化碳通量及其影响因素。研究结果表明, 该海域秋季溶解无机碳(DIC)高值区主要出现在调查海域东北部及长江口附近海域, 而调查海域南部DIC 含量较少且变化平缓, 其主要是受台湾东部流向东北方向的黑潮支流及长江冲淡水的影响; 表层海水CO₂分压(pCO₂)值变化范围为40.8～63.5 Pa, 呈现沿黑潮支流流入方向由东南向西北逐渐增高的趋势。秋季表层海水pCO₂与温度(T)、盐度(S)有较好的负相关性, 说明海水温度升高和盐度增加, pCO₂降低, 反之亦然。另外, 通过估算得出, 秋季CO₂海-气交换通量为2.69～33.66 mmol/(m²·d), 平均值为(14.35 ± 7.06 )mmol/(m²·d),其在长江口邻近海域相对较大, 而在调查海域南部相对较小; 2010 年秋季水体向大气释放CO₂的量(以碳计)为(2.35 ± 1.16)×104 t/d, 是大气CO₂较强的源, 说明东海中北部海域秋季总体上是CO₂的源。

Dissolved inorganic carbon and air-sea carbon exchange flux in the central and northern East China Sea in autumn

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.