Air-sea gas transfer in the Southern Ocean
Air-sea gas transfer in the Southern Ocean
复制标题
南大洋的海气输送
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Z. Top
中科院分区：
文献类型：
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作者：
R. Wanninkhof;K. Sullivan;Z. Top
[1]在南大洋铁肥化试验（SOFex）期间，利用双示踪技术测定了南大洋的气体输送速度。有目的地注入的示踪剂，六氟化硫和氦-3的减少，可以很好地描述了气体交换参数与风速，满足全球约束的基础上炸弹-14 C的吸收。示踪剂的浓度降低可以预测稍好与建立的关系，如果气体传输建模为立方体的函数，而不是风速的平方，特别是在一个时间间隔与高和可变的风。然而，这两种拟合都可以在观测的不确定性范围内对浓度降低进行建模。这表明，它将是非常困难的，以明确地确定是否二次或三次依赖的气体交换与风是更合适的基础上故意示踪剂测量。然而，这些结果表明，南大洋的气体交换率与海洋的其他部分相比并不异常。因此，这不能解释观测和基于模式的南大洋CO2吸收估计值之间的差异。利用从QuikSCAT卫星海风散射计获得的高质量风速场和既定的表层水pCO 2气候学，重新评估了南大洋（>34°S）的CO2吸收。总的吸收率是类似于以前的观测为基础的估计，但分析表明，吸收率是敏感的风速产品使用和风速分布。
[1] Gas transfer velocities were determined in the Southern Ocean during the Southern Ocean Iron Fertilization experiment (SOFex) using the dual deliberate tracer technique. The decrease of the purposefully injected tracers, sulfur hexafluoride and helium-3, could be well described by gas exchange parameterizations with wind speed that satisfy global constraints based on bomb-14C uptake. The concentration decrease of tracers could be predicted slightly better with established relationships if gas transfer was modeled as a function of the cube rather than the square of the wind speed, particularly over a time interval with high and variable winds. However, both fits can model the concentration decrease within the uncertainty of the observations. This suggests that it will be singularly difficult to definitively determine if a quadratic or cubic dependence of gas exchange with wind is more appropriate based on deliberate tracer measurements. However, these results show that gas exchange rates in the Southern Ocean are not anomalous when compared with the rest of the ocean. Thus this cannot account for discrepancy between observational and model-based estimates of uptake of CO2 in the Southern Ocean. Using a high-quality wind speed field obtained from the QuikSCAT satellite Seawinds scatterometer and an established surface water pCO2 climatology, the CO2 uptake in the Southern Ocean (>34°S) is reassessed. The total uptake rates are similar to previous observation-based estimates, but the analysis shows that the uptake rate is sensitive to wind speed product used and the wind speed distribution.