Highlights
- Freshwater content and mixing of Pacific water with Atlantic water determined the boundaries of aragonite undersaturation.
- The upper boundary deepened inside the Beaufort Gyre when anticyclonic circulation enhanced gyre intensity.
- The lower boundary was significantly lifted following an Atlantic-origin cold saline water intrusion event in 2017.
Abstract
This study evaluated interannual variation in the subsurface aragonite undersaturation zone (ΩAr<1 layer) in the Pacific Arctic Ocean, using data from the 2016–2019 period. The upper boundary (DEPΩ<1UB) of the ΩAr<1 layer generally formed at a depth where the contribution of corrosive Pacific water was approximately 98 %. The intensity of the Beaufort Gyre associated with freshwater accumulation mainly determined interannual variation in DEPΩ<1UB, but the direction of its effect was opposite west and east of ~166°W. The lower boundary (DEPΩ<1LB) of the ΩAr<1 layer was generally found at a depth range where equal contributions of Pacific and Atlantic water were expected. An Atlantic-origin cold saline water intrusion event in 2017 caused by an anomalous atmospheric circulation pattern significantly lifted the DEPΩ<1LB, thus the thickness of the ΩAr<1 layer decreased.
Mo A., Kim D., Yang E. J., Jung J., Ko Y. H., Kang S.-H., Cho K.-H., Park K. & Kim T.-W., 2022. Factors affecting the subsurface aragonite undersaturation layer in the Pacific Arctic region. Marine Pollution Bulletin 183: 114060. doi: 10.1016/j.marpolbul.2022.114060. Article (subscription required).
