North West Pacific

What is the role of finescale processes in a highly stratified current system?    

The Subtropical Countercurrent in the North Western Pacific is baroclinically unstable and produces energetic eddies. The horizontal gradients of SSH indicate the strength of this current. This information needs to be integrated with in situ data in order to understand energy pathways and heat balance in the North Pacific.

The North West Pacific campaign scientific aims to investigate this region as a case study of the role of submesoscale motions in the ocean energy pathway and in vertical heat transport, understand the impact of air-sea interactions on submesoscale dynamics, and provide a benchmark for validating Sea Surface Height observations by SWOT.

An in situ observing system will be deployed on the abyssal plain along the SWOT ground track to collect data during the SWOT fast sampling phase. Three moorings will be deployed using the Research Vessel “Dongfanghong 3” and maintained in place for at least one year. They will be put at the vertices of a triangle, at about 10 km one from the other and will collect hydrographic data over the upper 3000 m and velocity data above the main thermocline. This mooring system will be complemented by underwater and wave gliders that travel in between. With sufficient funding support, this observing system could be extended over a larger spatial domain by deploying additional moorings or gliders.  

This campaign will allow a better understanding the role of finescale processes in a highly stratified current system and will give insight of current ocean state in this region.

Surface currents (left panel) and relative vorticity ( ζ=vxuy) normalized by Coriolis frequency (f) (right panel) for the North West Pacific study site with SWOT grid overlaid (black lines). Images were generated using output from a high-resolution MITgcm simulation and are instantaneous snapshots from 1 July 2012.

Principal investigators: Zhao Jing (, Ge Chen (, Zhiwei Zhang (, Zhaohui Chen (

Institutes implicated in the campaign: Ocean University of China and Pilot National Laboratory for Marine Science and Technology, Qingdao, China

Contact point for the study site: Zhao Jing (