Composed vertical structure of mesoscale eddy in the northwestern Pacific Ocean

Abstract In this paper, we synthesize the vertical structure of mesoscale eddies in different regions of the northwestern Pacific Ocean by combining eddy dataset and Argo data. The results show that the temperature anomaly and salinity anomaly are negative within the cyclone eddies (CE) and positive within the anticyclone eddies (AC), while the density anomaly is the opposite. There are some differences in the structure of mesoscale eddies within different regions, and the Kuroshio Extension (KE) shows a significant single-core structure except for the temperature profile in the region of 135°E-150°E, which shows a weak double-core structure. The Subtropical Countercurrent (STCC) in the region between 135°E-165°E has a significant double-core structure, which is located in the mixed layer of the sea surface and 400 m below the sea surface, respectively. Meanwhile, the temperature anomaly, salinity anomaly and density anomaly of the Subtropical Countercurrent in the region between 120°E-165°E show a large variation in the depth of 200-300 m, which is different from the other subdivisions of the Subtropical Countercurrent. In addition, the closer the Kuroshio Extension or the Subtropical Countercurrent is to the west coast, the more pronounced the temperature anomaly appear. Finally, the temperature anomaly and salinity anomaly caused by the cyclonic eddies in the Kuroshio Extension are stronger than those caused by the anticyclonic eddies, while both are almost equal in the Subtropical Countercurrent. This may be further evidence of the influence of strong currents on mesoscale eddies.