Factors governing the oceanic nitrous oxide distribution: Simulations with an ocean general circulation model
Factors governing the oceanic nitrous oxide distribution: Simulations with an ocean general circulation model
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DOI：
10.1029/1999gb900032
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发表时间：
2000-03
影响因子：
5.2
通讯作者：
P. Suntharalingam;J. Sarmiento
中科院分区：
文献类型：
--
作者：
P. Suntharalingam;J. Sarmiento
开发了海洋一氧化二氮分布的全球模式，以评估目前对控制开放海洋中一氧化二氮形成和分布过程的理解。在全球海洋环流模型中，N2O被视为一种非保守的示踪剂，受海洋内部生物源和海洋表面气体交换的影响。一个简单的将N2O产生与氧气消耗联系起来的标量参数化(基于观测到的过量N2O与表观氧利用之间的相关性)成功地再现了观测到的分布的大尺度特征，即在上升流和生物生产力区域的高地表过饱和度，以及在少营养的副热带涡旋中接近平衡的数值。海洋中的大部分N2O源产生于上层水柱(600m以上)，并在地层的纬度带内直接排放到大气中。这个模型不能很好地再现观测到的深海结构，它显示了深海中N2O的过量产生。一种替代的源参数，它考虑了导致N2O产生和氧气消耗之间关系的深度变化的过程，产生了对深层分布的更好的表示。然而，海面分布和海-气通量主要由上层海洋来源决定，因此对深海N2O产生性质的变化相对不敏感。
A global model of the oceanic nitrous oxide distribution is developed to evaluate current understanding of the processes governing nitrous oxide formation and distribution in the open ocean. N2O is treated as a nonconserved tracer in a global ocean general circulation model subject to biological sources in the oceanic interior and gas exchange at the ocean surface. A simple scalar parameterization linking N2O production to oxygen consumption (and based on observed correlations between excess N2O and apparent oxygen utilization) is successful in reproducing the large‐scale features of the observed distribution, namely, high surface super‐saturations in regions of upwelling and biological productivity, and values close to equilibrium in the oligotrophic subtropical gyres. The majority of the oceanic N2O source is produced in the upper water column (over 75% above 600 m) and effluxes directly to the atmosphere in the latitude band of formation. The observed structure at depth is not as well reproduced by this model, which displays excessive N2O production in the deep ocean. An alternative source parameterization, which accounts for processes which result in a depth variation in the relationship between N2O production and oxygen consumption, yields an improved representation of the deep distribution. The surface distribution and sea‐air flux are, however, determined primarily by the upper ocean source and, therefore, are relatively insensitive to changes in the nature of deep oceanic N2O production.