Small-Scale Processes in the Upper Ocean and their Interaction with the Earth’s Climate System Working Group

The US CLIVAR Working Group on Small-Scale Processes in the Upper Ocean and their Interaction with the Earth’s Climate System was established in November 2024 and will continue through fall 2027. It brings together 17 scientists with expertise in small-scale physics theory, sea ice, submesoscale bio-physical interactions, high-resolution simulations, wind, waves, and clouds.

The upper ocean is crucial to our climate, with its intricate processes having wide-ranging effects on the Earth’s climate system. These processes occur at various time and space scales, from turbulence to large-scale circulation; however, small-scale processes, which cannot be directly modeled in global climate simulations, introduce uncertainty in understanding and forecasting climate variability. Small-scale processes break dynamical barriers, moving tracers between different components of the climate system and impacting boundaries like those between the deep and surface oceans, the ocean and atmosphere, coastal and open waters, and the ocean and ice regions. Understanding when, where, and how these processes take place, along with their future fate in a changing climate, is critical.

The need for this working group is highlighted by recent advancements in both modeling and observations, including the launch of the SWOT (Surface Water and Ocean Topography) mission and recent field campaigns such as the Sub-Mesoscale Ocean Dynamics Experiment (S-MODE). In addition, advances in high-resolution ocean modeling, such as efforts by NASA ECCO-GEOS to run coupled km-scale interactions offer powerful tools for understanding small-scale processes and multi-scale interactions. These innovations in satellites and high-resolution simulations position us at the threshold of a transformative period in small-scale oceanographic research.

It is important that the process-level insights gained from these advancements are translated into a broader understanding of their climate-scale impacts. This working group plays a pivotal role in accelerating the community’s adoption of these novel technologies and data sources by fostering an interdisciplinary community that will assess current scientific knowledge, pinpoint areas of need, and offer direction for the future in terms of theory, simulations, and observations. Its focus spans a wide range of areas (including the coasts and high-latitudes) of the ocean and other climate systems with a special focus on the 1 - 100km scales. 

Main Objectives of the Working Group

The dynamic nature of upper ocean processes and their fundamental role in the climate system require an interdisciplinary approach. This working group focuses on leveraging new satellite missions, regional field campaigns, and high-resolution coupled simulations to explore their potential for studying small-scale ocean processes and their interaction with other climate system components. Thus, the primary objectives of the working group are as follows:

1. Foster an interdisciplinary community: Cultivate a cohesive community that bridges disciplines with overlapping interests in upper ocean physics, marine biogeochemistry, and climate.
2. Review current gaps in theory, observations, and models: Identify existing gaps in the understanding of small-scale processes in the upper ocean’s role in the climate system and unite research communities, emphasizing their connections to climate variability.
3. Provide guidance on best practices: Develop guidelines on best practices for interdisciplinary research, including best practices on data management, code sharing, OSSE studies, using theory to guide campaign development, verification of theories from observations, and model-observation comparison.
4. Inform future observing system design: Provide insight and recommendations on the design of future observing systems, including guidance for future small-scale ocean observations from in-situ as well as space, and contribute to the NASA 2027 Decadal Survey.