Using stable isotopes to distinguish atmospheric nitrate production and its contribution to the surface ocean across hemispheres
Using stable isotopes to distinguish atmospheric nitrate production and its contribution to the surface ocean across hemispheres
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使用稳定同位素区分大气硝酸盐的产生及其对跨半球表面海洋的贡献
DOI：
10.1016/j.epsl.2021.116914
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发表时间：
2021-06
影响因子：
5.3
通讯作者：
Meredith G. Hastings
中科院分区：
文献类型：
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作者：
Guitao Shi;Hongmei Ma;Zhuoyi Zhu;Ze-Jun Hu;Zhenlou Chen;Su Jiang;Chunlei An;Jinhai Yu;Tianming Ma;Yuansheng Li;Bo Sun;Meredith G. Hastings
利用中国南极科考队（CHINARE）样带收集的大气和表层海水样品，研究了大气中硝酸盐（no3−）的来源和产生及其对海洋表面no3−库的贡献。大多数大气no3−集中在中等大小的颗粒上，北半球的浓度比南半球高纬度地区高得多。NO 3−的同位素（δ 15 N、δ 18 O和Δ 17 O）表明，沿海地区大气NO 3−的升高与人类活动有关，而南方高纬度地区的NO 3−则倾向于受光解作用驱动的南极积雪前兆排放的影响。总体而言，在表层海水的同位素与大气no 3−之间没有发现明确的关联，这表明海洋不太可能是该样带大气no x的重要直接来源。利用δ 18o和Δ 17o之间的显著线性关系来解释NO 3−产生的重要途径。在热带地区，大气中no3 -的50%是通过OH氧化no2产生的，而在南纬高纬度地区，氧同位素比率（δ 18o和Δ 17o）的升高表明，no3 -的产生通过BrO和/或DMS途径增加，假设n2o - 5通道的贡献很小。在表层海水中，沿海地区和南大洋存在较高的no3−浓度。在中国沿海地区，正的Δ 17 O值（1.7±1.0‰）提供了大气非循环沉积贡献的直接证据，其计算贡献至少为地表no3−总量的2-3%。在海水的其他地方都发现了Δ 17 O = 0，这表明大气沉积在表面no3−池中的存在很小。在南极洲附近，极低δ 15 N（< - 30‰）的大气NO 3−沉积会降低海冰中的δ 15 N，这一过程可能对评估海冰中的氮循环具有同位素意义。•no3−的浓度和同位素组成呈现显著的纬度梯度。•大气中的no3−主要通过热带地区的OH氧化产生。•南部高纬度地区显示出BrO或DMS通路的重要性增加。•海水no3−的Δ 17 O阳性分布在沿海水域，其他地区为Δ 17 O≈0。•南极洲附近的大气沉降可降低海冰中no3−的δ 15 N。
Atmospheric samples and surface seawater collected on a Chinese Antarctic Research Expedition (CHINARE) transect are used to investigate sources and production of nitrate ( NO 3 − ) in the atmosphere and its contribution to the surface NO 3 − pool in the ocean. Most atmospheric NO 3 − is concentrated on intermediate size particles, and much higher concentrations were observed in the northern hemisphere than in the high southern latitudes. Isotopes of NO 3 − ( δ 15 N , δ 18 O and Δ 17 O ) suggest that elevated atmospheric NO 3 − in coastal areas was associated with human activities, while NO 3 − in the high southern latitudes tends to be influenced by precursor Antarctic snowpack emissions driven by photolysis. In general, no clear association was found between the isotopes of surface seawater and atmospheric NO 3 − , suggesting that the ocean is unlikely to be an important direct source of atmospheric NO x on this transect. A significant linear relationship between δ 18 O and Δ 17 O of NO 3 − is used to interpret important pathways for NO 3 − production. In the tropics, >59% of atmospheric NO 3 − is produced via OH oxidation of NO 2 , while the elevated oxygen isotopic ratios ( δ 18 O and Δ 17 O ) in the high southern latitudes suggest increased NO 3 − production via BrO and/or DMS pathways assuming a minor contribution of the N 2 O 5 channel. In surface seawater, high NO 3 − concentrations are present in the coastal areas and in the Southern Ocean. In coastal areas of China, positive Δ 17 O values in seawater NO 3 − (1.7 ± 1.0‰) provide direct evidence of uncycled atmospheric deposition contribution, with a calculated contribution of at least 2-3% to total surface NO 3 − . A Δ 17 O = 0 was found everywhere else in seawater, suggesting that atmospheric deposition has a minimal presence in the surface NO 3 − pool. Near Antarctica, deposition of atmospheric NO 3 − with extremely low δ 15 N ( < − 30 ‰ ) could lower δ 15 N found in sea ice, and this process could be isotopically important to evaluate nitrogen cycling in sea ice. • Concentration and isotopic composition of NO 3 − show notable latitudinal gradients. • Atmospheric NO 3 − is mainly produced via OH oxidation in the tropics. • The high southern latitudes show an increased importance of BrO or DMS pathways. • Positive Δ 17 O of seawater NO 3 − is found in coastal waters and Δ 17 O ≈ 0 in other areas. • Atmospheric deposition near Antarctica can lower δ 15 N of NO 3 − in sea ice.
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影响因子：
--
作者：
A. Rankin;E. Wolff;Seelye Martin
通讯作者：
A. Rankin;E. Wolff;Seelye Martin
区分南极东部冰盖夏季大气中硝酸盐的产生
影响因子：
5
作者：
Shi G;Buffen A M;Ma H;Hu Z;Sun B;Li C;Yu J;Ma T;An C;Jiang S;Li Y;Hastings M G
通讯作者：
Hastings M G
影响因子：
5
作者：
Kazuki Kamezaki;S. Hattori;Yoko Iwamoto;S. Ishino;H. Furutani;Yusuke Miki;M. Uematsu;K. Miura
通讯作者：
Kazuki Kamezaki;S. Hattori;Yoko Iwamoto;S. Ishino;H. Furutani;Yusuke Miki;M. Uematsu;K. Miura
影响因子：
5.2
作者：
Jing Zhang;Guosen Zhang;Yan-feng Bi;S. M. Liu
通讯作者：
Jing Zhang;Guosen Zhang;Yan-feng Bi;S. M. Liu
影响因子：
6.3
作者：
J. Savarino;W. Vicars;M. Legrand;S. Preunkert;B. Jourdain;M. Frey;A. Kukui;N. Caillon;J. G. Roca
通讯作者：
J. Savarino;W. Vicars;M. Legrand;S. Preunkert;B. Jourdain;M. Frey;A. Kukui;N. Caillon;J. G. Roca