Could Artificial Downwelling/Upwelling Mitigate Oceanic Deoxygenation in Western Subarctic North Pacific?
Could Artificial Downwelling/Upwelling Mitigate Oceanic Deoxygenation in Western Subarctic North Pacific?
复制标题
DOI：
10.3389/fmars.2021.651510
复制
发表时间：
2021-09
期刊：
影响因子：
--
通讯作者：
Canbo Xiao;W. Fan;Ying Chen;Yao Zhang;K. Tang;N. Jiao
中科院分区：
文献类型：
--
作者：
Canbo Xiao;W. Fan;Ying Chen;Yao Zhang;K. Tang;N. Jiao
副极地环流区域，如西亚北极北太平洋（WSNP）含有缓慢的低氧水，并受到氧气损失（脱氧）的威胁。我们在RCP 8.5排放情景下的模拟表明，安装管道诱导人工下降流和上升流（AD和Au）提供了短期解决方案，以对抗WSNP中的脱氧。在没有工程的情况下，到2100年，WSNP的地下氧将减少30-100 mmol/m3。相反，持续实施AD和Au可以对抗这种下降趋势，AD比Au更有效。氧合效应主要是两种工程方案如何通过物理过程垂直重新分配氧气的结果。AD通过向海洋内部平流输送表层水和随后增强的密度跃层混合直接改善了深度处的氧气，而Au通过在管道外部产生补偿性下降流来做到这一点。这两种方案都需要近40年的时间才能完成氧化。在此之后，氧气在WSNP中达到新的平衡状态，而没有通过工程进一步改善。AD和Au都强烈地增加部署地点周围的初级生产，但仅导致地下水中有氧呼吸的微弱增强，因此对氧合的影响较小。与本世纪内快速气候变化造成的影响相比，其他不必要的环境副作用可以忽略不计，包括二氧化碳的释气、pH值降低和降水减少。
Subpolar gyre regions such as the Western Subarctic North Pacific (WSNP) contain sluggish, low-oxygen water, and are threatened by loss of oxygen (deoxygenation). Our simulations under RCP 8.5 emission scenario suggest that installing pipes to induce artificial downwelling and upwelling (AD and AU) provides short-term solutions to combat deoxygenation in the WSNP. With no engineering, the WSNP's subsurface oxygen decreases by 30–100 mmol/m3 by the year 2100. Continuous implementation of AD and AU instead counters this declining trend, and AD is more effective than AU. The oxygenation effect is primarily a consequence of how the two engineering schemes vertically redistribute oxygen via physical processes. AD directly improves oxygen at depth via advecting surface water toward the ocean interior and subsequent enhanced pycnocline mixing, and AU does so via generating compensatory downwelling outside of the pipes. Both schemes take near 40 years to complete the oxygenation. After that, oxygen reaches a new equilibrium state in the WSNP with no further improvement by the engineering. AD and AU both strongly increase primary production surrounding the deployment sites, but lead only to weak enhancement of aerobic respiration in subsurface water and thus a minor impact on the oxygenation. Other unwanted environmental side effects are negligible compared to those caused by rapid climate change within this century, including outgassing of carbon dioxide, pH decrease, and precipitation reduction.