Formation and Subduction of North Pacific Tropical Water and Their Interannual Variability

• DOI: 10.1175/jpo-d-13-031.1
• Publication Date: 2013-09-04T19:38:01Z
• Authors: Shota Katsura; Eitarou Oka; Bo Qiu; Niklas Schneider
• Keywords: Mixed layer; Argo; Stratification (seeds); Entrainment (biomusicology)

Abstract Formation and subduction of the North Pacific Tropical Water (NPTW), its interannual variability, associated mechanisms were investigated by using gridded Argo-profiling float data various surface flux in 2003–11. The NPTW has two formation sites center subtropical gyre, corresponding to regional sea salinity maxima. Mixed layer variations these found be significantly different. While seasonal variation was prominent eastern site, dominant western site. mixed site controlled mainly evaporation, precipitation, entrainment fresher water below closely related depth. In effect is small due a vertical difference across base, excess evaporation over precipitation that tended balanced eddy diffusion, whose strength varied interannually association with decadal oscillation. After subduction, denser formed dissipated quickly, while lighter one advected westward as far Philippine Sea, transmitting away from region.