Seasonality of Dissolved Organic Carbon in the Upper Northeast Pacific ocean
Seasonality of Dissolved Organic Carbon in the Upper Northeast Pacific ocean
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DOI：
10.1029/2018gb006152
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发表时间：
2019-05-01
影响因子：
5.2
通讯作者：
Hansell, Dennis A.
中科院分区：
文献类型：
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作者：
Bif, Mariana B.;Hansell, Dennis A.
从2017年东北太平洋的季节游轮中，我们(1)测定了溶解有机碳浓度；(2)根据硝酸盐下降计算了净群落生产量(NCP)；(3)建立了NCP与75m上层季节性溶解有机碳(DOC)累积量之间的关系。不同季节、不同年份海洋站PAPA的净溶解生产量比约为0.26。利用2009-2018年在PAPA海洋站附近作业的Bio-Argo浮标获得的硝酸盐浓度剖面，我们在高时间分辨率下计算了NCP，然后应用0.26常量来(4)估计DOC的9年变异性。我们发现海洋站PAPA附近具有很强的季节性，夏季NCP最大值在0.3-2.9molC/m(2)之间，表层DOC浓度估计在冬季的56mU/kg到夏季的73mU/kg之间。溶解有机碳的季节性累积库存量有10倍的年际变化，范围从0.078至0.75molC/m(2)。这项研究强调了部署配备化学传感器的浮标的价值，以便更好地了解海洋生物地球化学循环，特别是在以其他方式无法获得高分辨率数据的情况下。考虑到大约26%的NCP以DOC的形式积累在阿拉斯加湾中部，剩余的大约74%的NCP可以作为下沉的生物成因颗粒出口。
From seasonal cruises in the NE Pacific Ocean during 2017, we (1) determined dissolved organic carbon concentrations; (2) calculated net community production (NCP) from nitrate drawdown; and (3) established relationships between NCP and seasonal dissolved organic carbon (DOC) accumulation in the upper 75 m. The fraction of NCP that accumulated as DOC, hereafter referred to as the net dissolved production ratio, was calculated for several stations during spring and summer. The net dissolved production ratio was about 0.26 at the oceanic station Ocean Station Papa during different seasons and years. Using nitrate concentration profiles obtained from Bio-Argo floats during 2009-2018 operating near Ocean Station Papa, we calculated NCP at high temporal resolution and then applied the 0.26 constant in order to (4) estimate DOC variability for the 9-year period. We found strong seasonality near Ocean Station Papa, with NCP maxima during summers ranging from 0.3 to 2.9 mol C/m(2) and surface DOC concentrations estimated from 56 mu mol/kg in winters to 73 mu mol/kg in summers. There was a 10-fold interannual variability in the seasonally accumulated inventory of DOC, ranging from 0.078 to 0.75 mol C/m(2) . This study reinforces the value of deploying floats equipped with chemical sensors in order to better understand marine biogeochemical cycles, especially when high resolution data cannot be obtained otherwise. Given that similar to 26% of NCP accumulates as DOC in the central Gulf of Alaska, the remaining balance of similar to 74% is available for export as sinking biogenic particles.