To improve the understanding on the ocean physical processes that relate to living marine resources is one of the main goals of POC. To this end, much effort has been made towards the ocean mesoscale dynamics and its impact on the marine ecosystem, while the sub-mesoscale processes, of one or two orders smaller in spatial scale, have received comparatively few attentions. The sub-mesoscale process is a ubiquitous phenomenon over the entire ocean and has been a front edge of oceanography during past decade. The PICES Working Group 38 (WG 38) on Mesoscale and Sub-mesoscale Processes ended this year. While WG 38 has done a detailed and thorough work on the mesoscale processes on the North Pacific, the sub-mesoscale processes were not focused on sufficiently and completely due to the large volume of mesoscale studies. It is therefore timely to transition from mesoscale to sub-mesoscale at this moment on the basis of the results of WG 38.
Sub-mesoscale processes are relevant to ocean primary productivity because they support large vertical velocity with timescale similar to the phytoplankton growth, which will ultimately influence the upper trophic levels and food chain. This new group aims to “improving our essential knowledge on the sub-mesoscale processes by integrating the sub-mesoscale-permitting observation dataset, developing and evaluating the high-resolution coupled model in the North Pacific, particularly in the coastal areas and others with important living resources”. The establishment of this group helps address the FUTURE goal on the variability of marine ecosystem under natural and anthropogenic forcings across scales. The working group will also develop tight collaboration with national and international work groups and promote more studies on this topic.