Ocean-atmosphere interaction is central to the climate system, with exchanges of heat and momentum driving both atmospheric and oceanic variability and circulation across a wide-range of time and…

The University of Maryland, College Park received a $361,063 grant award from a civilian federal agency for research on air-sea interaction and coupling at the ocean submesoscale. The award, which commenced February 3, 2021 and concluded January 31, 2025, supports fundamental research examining how the ocean and atmosphere exchange heat and momentum at fine spatial scales (0.1-10 kilometers). The project leverages high-resolution observations from NASA's Earth Venture Suborbital-3 Sub-Mesoscale Ocean Dynamics Experiment (EVS-3 S-MODE), coupled global simulations using GEOS/ECCO models, and satellite data to advance understanding of air-sea coupling mechanisms at scales previously inaccessible to researchers.

The research initiative pursues three primary objectives: clarifying the basic physical mechanisms of air-sea interaction at the ocean submesoscale through analysis of NASA observations and process-study modeling; quantifying the regional and global importance of fine-scale air-sea interaction using high-resolution global coupled simulations; and understanding the broader consequences for ocean circulation. The work was performed at the University of Maryland, College Park campus in College Park, Maryland, with no set-aside designation applied. As a child award under the University System of Maryland parent entity, this grant advances the institution's significant portfolio of federally-funded research in Earth sciences, climate systems, and oceanographic studies conducted in collaboration with NASA and other civilian research agencies.

Ocean-atmosphere interaction is central to the climate system, with exchanges of heat and momentum driving both atmospheric and oceanic variability and circulation across a wide-range of time and spatial scales. These interactions are often characterized by coupling between the atmosphere and ocean where surface fluxes induce variability on one-side of the air-sea interface that then feeds back to modify the evolution of the other fluid. However, despite a growing recognition that surface ocean variability is rich with processes at the submesoscale (horizontal scales of 0.1-10 KM), the role of this variability in air-sea interaction, and whether there are significant coupled interactions at this scale, remains largely unknown. The work proposed here will therefore extend the frontier of air-sea coupling down to finer scales than have previously been accessible, developing a more complete understanding of the mechanisms and impact of air-sea coupling at the submesoscale, and the consequences for ocean circulation. These advances will be enabled through leveraging unique and timely high-resolution observations of the air-sea interface planned to be collected as part of the NASA earth venture suborbital-3 sub-mesoscale ocean dynamics experiment (EVS-3 s-mode), high-resolution coupled global simulations (geos/ecco), and satellite data. The proposed work has three primary objectives: objective 1: improve our understanding of the basic physical mechanisms of air-sea interaction and coupling at the ocean submesoscale. Unique new observations planned as part of the NASA EVS-3 s-mode project will be analyzed in concert with high resolution process study modeling to clarify the basic physical mechanisms through which the ocean and atmosphere interact at small scales. Objective 2: quantify the regional and global importance of fine-scale air-sea interaction. A new high-resolution global 1/48 coupled geos/ecco solution provides a test bed for evaluating existing and new theories of air-sea interaction. The focus of this activity will be on how air-sea interaction processes affect the large-scale properties of the ocean mixed-layer and circulation. Objective 3: assess the capabilities of current and future remote sensing for observing submesoscale air-sea interaction. High resolution satellite data will be used for observational case studies of air-sea interaction at the submesoscale, providing both a more complete description of the relevant physical processes, and guidance on the observational requirements for remote sensing. Impact and relevance: the proposed work will therefore improve our understanding of coupled air-sea interaction at the ocean submesoscale, a key source of uncertainty in our ability to understand and predict ocean circulation and variability. This responds directly to the NASA physical oceanography program s goal of understanding the ocean s role in climate variability and prediction , and the priority research theme of analysis and interpretation of ocean circulation using satellite and in situ data, data-derived products and NASA ocean state estimates , and is a priority of the U.S. Clivar program. Analysis of the NASA EVS-3 s-mode data, in conjunction with new process-study models, will add significant value to that project. Likewise, we will provide ground-truth validation of the new geos/ecco simulation, which will be used widely in the oceanographic community, including to support the science objectives of the upcoming NASA swot mission. Analysis of satellite data, along with geos/ecco, will help guide the interpretation of current and future scatterometer wind data, and help shape the science requirements of future missions. Finally, as part of this project a PHD student and undergraduate summer researcher will both be trained in physical oceanography and satellite data analysis.