Decadal Variability of North Pacific Eastern Subtropical Mode Water. Issue 9 (3rd September 2018)

• Record Type: Journal Article
• Authors: Guo, Yongqing; Lin, Xiaopei; Wei, Meng; Liu, Cong; Men, Guang
• Is Part Of: Journal of geophysical research. Volume 123:Issue 9(2018)
• Page Start: 6189
• Page End: 6206
• Publication Date: 2018-09-03
• Subjects: Oceanography -- Periodicals; 551.4605
• DOI: 10.1029/2018JC013890
• Languages: English
• ISSNs: 2169-9275

Abstract

Abstract: A significant decadal variability of the North Pacific Eastern Subtropical Mode Water (NPESTMW), related to the Pacific Decadal Oscillation, is identified from the gridded Argo and EN4 observational data sets. To investigate the decadal variability of the NPESTMW volume, the high‐resolution Estimating the Circulation and Climate of the Ocean, Phase II simulation is used to diagnose the volume budget of the NPESTMW density layer in the NPESTMW formation region (20°–36°N, 160°–120°W) between 1992 and 2016. Results show that NPESTMW is formed through subduction of low potential vorticity (PV) water. This low‐PV water subduction is mainly determined by mixed layer depth change and lateral induction, which account for approximately 58% and 32%, respectively. The decadal NPESTMW volume anomaly is originated from the Pacific Decadal Oscillation‐induced decadal anomaly of air‐sea buoyancy flux. This decadal buoyancy flux anomaly drives the decadal anomaly of mixed layer depth change, then causes anomalous subduction, and leads to anomalous low‐PV water subduction. The decadal NPESTMW volume anomaly is finally generated by this anomalous low‐PV water subduction. Key Points: NPESTMW is formed through subduction of low‐PV water, which is mainly determined by MLD change (58%) and lateral induction (32%) The NPESTMW volume shows a PDO‐related decadal variability; when the PDO is in a positive (negative) phase, less (more) NPESTMW appears The decadal NPESTMW volume anomaly is originated from the PDO‐induced decadal anomaly of air‐sea buoyancy flux