Contribution of upwelling to air‐sea N 2 O flux at the tip of the Antarctica Peninsula

• Published in: Limnology and Oceanography
• Main Authors: Zhan, L., Chen, L., Zhang, J., Li, Y., Wu, M., Liu, J.
• Other Authors: National Natural Science Foundation of China
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2018
• Subjects: Antarctic; Antarctic Peninsula; Bransfield Strait; Powell Basin; Scotia Sea; The Antarctic; Weddell; Weddell Sea; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1002/lno.11004; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Flno.11004; https://onlinelibrary.wiley.com/doi/pdf/10.1002/lno.11004; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/lno.11004; https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lno.11004

Abstract During the 28 th Chinese National Antarctic Research Expedition, the seas adjacent to the tip of the Antarctic Peninsula (TAP), including the Scotia Sea, parts of the Bransfield Strait, and the Powell Basin, were investigated. The results show that the vertical distributions of N 2 O on both sides of the TAP are similar but that elevated N 2 O concentrations and corresponding upper circumpolar deep water (CDW) signals in the Scotia Sea are absent from the Powell Basin, where the largest areas of Weddell Sea deep water were observed during this cruise. The average air‐sea N 2 O flux of the study area is ~ 8.83 ± 3.32 μ mol m −2 d −1 , suggesting that these waters, while significant, are not an overwhelming source of atmospheric N 2 O. The results of one dimensional box model indicate that the upwelling of the CDW contributes to the N 2 O flux north of TAP. The water to the south of the TAP is colder than that to the north of TAP, and the presence of cold winter water in the south tends to keep the N 2 O‐rich Weddell Deep Water from upwelling to the surface. CDW, enriched in N 2 O, was observed to upwell toward the surface layers resulting in oversaturation and outgassing to the atmosphere in waters north of TAP. In contrast, waters to the south which were dominated by cold winter water were generally in equilibrium with the atmosphere.