Spatial distribution of riverine DOC inputs to the ocean: an updated global synthesis
Spatial distribution of riverine DOC inputs to the ocean: an updated global synthesis
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DOI：
10.1016/j.cosust.2012.03.003
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发表时间：
2012-05-01
影响因子：
7.2
通讯作者：
Cai, Wei-Jun
中科院分区：
文献类型：
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作者：
Dai, Minhan;Yin, Zhiqiang;Cai, Wei-Jun
本研究根据最新的文献数据，评估了溶解有机碳（DOC）流入海洋的情况。利用世界118条河流的DOC浓度和长期平均河流排放量，我们估计流入沿海海域的DOC河流量为0.21 Pg C yr(-1)。当我们考虑到运输到北极期间 DOC 的去除时，该通量减少至 0.19 Pg C yr(-1)。当我们对流入沿海海洋的其余河流DOC进一步采用10%的平均去除率时，我们得到的全球河流DOC通量估计为0.17 Pg C yr(-1)，处于先前估计的下限。考虑到河流端员DOC浓度的季节变化，我们目前对全球河流DOC排放量的估计存在约30%的不确定性。进入海洋的DOC通量在其来源大陆、受纳近海、洋盆和纬度带方面具有显着的空间变化。 DOC 通量最高的是从南美洲进入西部海洋边界，最终进入大西洋。河流DOC排放最丰富的是低纬度地区，0-30°N和0-30°S区域的Tg C yr(-1)分别为38.0和90.0 Tg C yr(-1)，两者合计约占全球DOC输入量的62%。根据这些更新的通量，我们估计全球河流平均 DOC 浓度为 5.29 mg L-1。
On the basis of most up-to-date literature data, this study evaluated the influxes of dissolved organic carbon (DOC) to the ocean. Using the DOC concentrations in 118 world rivers and long-term average river discharges, we estimated the river influxes of DOC to the coastal seas as 0.21 Pg C yr(-1). This flux was reduced to 0.19 Pg C yr(-1) when we took into account DOC removal during its transport into the Arctic. When we further adopted an average removal rate of 10% for the rest of the river DOC input into the coastal ocean, we obtained an estimate of the global river DOC flux of 0.17 Pg C yr(-1), which is at the lower end of prior estimations. Considering the seasonal variation of the river end-member DOC concentration, our current estimate of the global river DOC discharge is subject to an uncertainty of similar to 30%.DOC fluxes into the ocean have significant spatial variations in terms of their continents of origin, recipient coastal seas, ocean basins and latitudinal zones. The highest DOC flux was from South America into the western ocean boundaries and eventually into the Atlantic Ocean. The most abundant riverine DOC discharge was in the low latitudinal zones with 38.0 and 90.0 Tg C yr(-1) in the 0-30 degrees N and 0-30 degrees S zones, respectively, the combination of which accounted for similar to 62% of the global DOC input. On the basis of these updated fluxes, we estimated a global river mean DOC concentration of 5.29 mg L-1.