Effects of mixing on the subduction of South Pacific waters identified by a simulated passive tracer and its adjoint

• Published in: Dynamics of Atmospheres and Oceans
• Main Authors: Gao, Shan, Qu, Tangdong, Fukumori, Ichiro
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: Subduction; Mixing; Tracer; South Pacific; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography; Antarctic; Pacific; Antarc*
• Online Access: http://ir.qdio.ac.cn/handle/337002/11568; https://doi.org/10.1016/j.dynatmoce.2010.10.002

Effects of mixing on water mass subduction are analyzed in the South Pacific Ocean. Model simulations using a passive tracer and its adjoint are employed in conjunction with a particle tracking method to distinguish effects of mixing from those of advection. The results show that mixing processes can contribute to as much as 20% of the overall subduction rate in the South Pacific. Of this mixing contribution, about 30% can be attributed to meso-scale eddies, including their associated bolus transport, while the major part (70%) is due to other diabatic processes. The impact of mixing reaches its maximum near the Sub-Antarctic Front, accounting for nearly 30% of the total subduction rate. Consequently, estimates based on tracing particles or on advection alone may significantly underestimate the subduction rate in the South Pacific Ocean. (C) 2010 Elsevier B.V. All rights reserved. Effects of mixing on water mass subduction are analyzed in the South Pacific Ocean. Model simulations using a passive tracer and its adjoint are employed in conjunction with a particle tracking method to distinguish effects of mixing from those of advection. The results show that mixing processes can contribute to as much as 20% of the overall subduction rate in the South Pacific. Of this mixing contribution, about 30% can be attributed to meso-scale eddies, including their associated bolus transport, while the major part (70%) is due to other diabatic processes. The impact of mixing reaches its maximum near the Sub-Antarctic Front, accounting for nearly 30% of the total subduction rate. Consequently, estimates based on tracing particles or on advection alone may significantly underestimate the subduction rate in the South Pacific Ocean. (C) 2010 Elsevier B.V. All rights reserved.