• Acronym: WG-57
• Parent Committee: POC
• Established: PICES-2025
  (GC Decision 2025/S/13)
• Duration: PICES-2025 - PICES-2028
  
• Mailing List

Oceanic finescale processes are loosely referred to as dynamical processes with horizontal scales of (0.01-100) km including mesoscale eddies, submesoscale processes, fronts, and internal waves, etc. These finescale processes play crucial roles in mediating oceanic energy cascade, biogeochemical and heat transport, and air-sea exchanges, and thus have significant impacts on the marine ecosystem and climate variations. For instance, the strong vertical motions induced by submesoscale processes can, on one hand, increase the primary productivity through upwelling and, one the other hand, facilitate the carbon export through downwelling, both of which having profound influences on biogeochemical cycles, ecosystems, and climate. However, the transient and small-size nature of finescale processes makes their observations and simulations challenging and critical gaps exist in understanding their mechanisms of energy cascade and tracer transport and their pathways in modulating the North Pacific ecosystems and climate. In particular, because the prevailing global models are still too coarse to resolve the finescale processes, their energy cascading and tracer transporting effects have to be parameterized in models. Improper parameterizations of finescale processes can lead to significant biases in projections of ocean warming, acidification, deoxygenation, and thus marine biodiversity and climate resilience.

The PICES Working Group 38 (WG 38) on “Mesoscale and Sub-mesoscale Processes” has ended in 2019, and the WG 50 on “Sub-mesoscale Processes and Marine Ecosystems” will be ended this year. While WG 38 and WG 50 have done a lot of work on meso- and submesoscale processes, additional finescale processes such as internal waves are not included. Furthermore, model parameterizations of finescale processes were not considered. It is timely and scientifically meaningful to transition from the tasks of the above two WGs to our proposed new WG: “Oceanic Finescale Processes: Impacts and Parameterizations”.

The new WG aims to (1) collecting and integrating high-resolution observational datasets and simulation outputs and data analysis methods to better study finescale processes, (2) better understanding the physics of finescale processes and their impacts on the North Pacific climate variations, (3) enhancing the knowledge finescale processes’ roles in biogeochemical processes (e.g., primary production and carbon export) and their impacts on the North Pacific ecosystems, (4) evaluating and developing parameterizations of finescale processes and (5) evaluating their influences on the models’ performance in the North Pacific”. The establishment of this WG helps to understand the status and changes of North Pacific ecosystems and climate and to improve the models’ simulation and projection capabilities on these issues. It will also develop tight collaborations with international colleagues to promote studies on the relevant topics.

This working group aligns closely with PICES’ vision of fostering trans-disciplinary, multinational collaborations to advance understanding of North Pacific ecosystems and enhance resilience. By integrating high-resolution observations and simulations, the group directly supports PICES’ mission to coordinate marine research through data exchange and methodological innovation. The PICES have 6 Goals in terms of “Advance Scientific Knowledge”. The initiative fosters collaboration (Goal 1) by uniting observational oceanographers, ocean modelers, and ecosystem scientists across nations to address finescale dynamics. It advances understanding of ecosystem status, vulnerability, and resilience (Goal 2) by quantifying how finescale processes—such as mesoscale eddies, submesoscale processes, and internal waves—mediate responses to natural forcings and human activities (Goal 3). The usage and development of parameterizations enhance modeling tools (Goal 4), improving projections of climate variability and ecosystem shifts under anthropogenic pressures. By curating and disseminating datasets and analytical methods, the group ensures timely access to critical scientific information (Goal 5). Furthermore, engaging early-career scientists in cutting-edge data-model integration sustains a vibrant PICES community (Goal 6). Ultimately, this work bridges observational and modeling gaps, strengthening the scientific foundation needed to assess and mitigate ecological risks in a changing North Pacific—a core pillar of PICES’ strategic priorities.

Linkage(s) to Previous PICES Expert Groups Activities
WG 38: Mesoscale and Submesoscale Processes
WG 50: Sub-mesoscale Processes and Marine Ecosystems

Terms of Reference

1. Review recent advances in finescale processes and their parameterizations in North Pacific to identify key knowledge gaps and innovation opportunities.
2. Assess the availability, accessibility, and interoperability of observation and simulation datasets to study finescale processes in the North Pacific.
3. Integrate multi-platform observational data (e.g., satellites, moorings, gliders, and drifters) with high-resolution model outputs to depict spatiotemporal variability of finescale processes in the North Pacific.
4. Identify the mechanisms and pathways how finescale processes modulate the North Pacific biogeochemical cycles, ecosystem, and climate variations.
5. Evaluate the existing and develop new parameterization schemes for unresolved finescale processes in North Pacific models.
6. Evaluate the performance of numerical models with embedded finescale parameterizations under different climate scenarios.
7. Promote collaborations for data sharing, capacity-building workshops, and early-career mentorship to enhance research on finescale processes.

Time Line and Expected Deliverables
Year 1 (2026)

1. Convene an inaugural workshop (virtual/hybrid) to introduce the members and discuss the Terms of Reference (TOR) of the new WG.
2. Review research advances in finescale processes in North Pacific and the relevant parameterizations (TOR 1).
3. Assess the finescale datasets to study finescale processes in the North Pacific (TOR 2).
4. Integrate observational/model data to depict spatiotemporal variability of finescale processes in the North Pacific (TOR 3)

Year 2 (2027)

1. Convene a hybrid workshop focused on TOR 3–5.
2. Identify mechanisms linking finescale processes to North Pacific biogeochemical cycles, ecosystem, and climate variations (TOR 4).
3. Evaluate existing parameterization schemes for finescale processes (TOR 5)
4. Develop new parameterization schemes for finescale processes (TOR 5)

Year 3 (2028)

1. Evaluate performance of numerical models with embedded finescale parameterizations (TOR 6).
2. Final workshop (in-person) to review TOR 1–6.
3. Finalize collaborative frameworks (TOR 7) and compile project outcomes.

Expected Deliverables

1. Annual progress reports to PICES, highlighting advancements against TOR objectives.
2. Mentorship partnerships linking early-career scientists with modeling/observational experts on finescale processes.
3. A review paper synthesizing research advances, current knowledge gaps, and innovation priorities in North Pacific finescale processes and parameterizations.
4. A peer-reviewed article on finescale modulation pathways for North Pacific ecosystem and climate variations.
5. A report on best practices for finescale parameterization in North Pacific models with guidelines for integrating finescale processes into policy-relevant models.

The new WG will collect the observational and model data used to study finescale processes in the first year. After these data are evaluated and quality control processed, they will be freely and openly shared with the PICES member countries and beyond in the second year. All of the data will meet the FAIR Guiding Principles (Findable, Accessible, Interoperable and Reusable, Wilkinson et al., 2016) to the greatest extent practicable.