Shipboard observations of atmospheric oxygen in the Southern Ocean during the 2017-2018 austral summer
Shipboard observations of atmospheric oxygen in the Southern Ocean during the 2017-2018 austral summer
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2017-2018年夏季南大洋大气氧的船上观测
DOI：
10.1016/j.polar.2021.100691
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
and S. Aoki
中科院分区：
文献类型：
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作者：
Morimoto;S.;S. Takebayashi;D. Goto;G.Hashida;and S. Aoki
研制了连续观测大气中氧气（定义为δ(O2/N2)）和二氧化碳（CO2）摩尔分数的原位测量系统，并于2017-2018年在SHIRASE 5003科考船上进行了连续观测，该科考船在澳大利亚和南极洲Syowa站之间航行。与δ(O2/N2)相比，南大洋co2的变化较小，表明陆地生物圈和化石燃料产生的co2和co2排放对观测结果的影响微不足道。因此，观测到的大气中O2/ n2的显著变化可归因于大气-海洋气体交换。在2017年12月的南行航次中，我们观察到由于海洋生物生产，巡航轨道西侧δ(O2/N2)的空间变化较大。基于简单模式的海洋O2通量和大气δ(O2/N2)变率与过去的海洋观测结果一致。2017年12月和2018年2 - 3月，60°S以南纬度地区δ(O2/N2)没有明显的纵向梯度。然而，2017年12月海洋生物生产活跃的区域出现了局部δ(O2/N2)最大值。这些观测结果表明，局部O2通量也可以改变南大洋大气δ(O2/N2)的空间分布。
An in situ measurement system was developed for continuous observations of the mole fractions of atmospheric oxygen (defined as δ(O2/N2)) and carbon dioxide (CO2) and the continuous observation was conducted onboard the research vessel SHIRASE 5003 during its voyage between Australia and Syowa Station, Antarctica, in 2017–2018. The CO2variation was low with respect to that of δ(O2/N2) in the Southern Ocean, suggesting that the land biospheric and fossil-fuel derived CO2and O2emissions negligibly influenced the observations. Therefore, the observed significant variations in the atmospheric O2/N2can be attributed to the atmosphere-ocean gas exchange. During the southbound voyage in December 2017, we observed large spatial variations in δ(O2/N2) due to marine biological production on the western side of the cruise track. Oceanic O2fluxes based on a simple model and atmospheric δ(O2/N2) variability were consistent with past oceanic observations. No clear longitudinal gradient in δ(O2/N2) was observed at latitudes toward south of 60° S in December 2017 and February–March 2018. However, local δ(O2/N2) maxima were observed in regions with active marine biological production in December 2017. These observations indicate that local O2fluxes can also modify the spatial distribution of atmospheric δ(O2/N2) in the Southern Ocean.