CaltechAUTHORS
Published April 1, 2025 | Version Published
Journal Article Embargoed

S-MODE: The Sub-Mesoscale Ocean Dynamics Experiment

Creators

  • 1. ROR icon Woods Hole Oceanographic Institution
  • 2. ROR icon University of Washington Applied Physics Laboratory
  • 3. ROR icon Jet Propulsion Lab
  • 4. ROR icon Scripps Institution of Oceanography
  • 5. ROR icon University of Rhode Island
  • 6. ROR icon University of Connecticut
  • 7. ROR icon University of North Carolina Wilmington
  • 8. ROR icon Colorado School of Mines
  • 9. ROR icon Ames Research Center
  • 10. ROR icon Stennis Space Center
  • 11. ROR icon Brown University
  • 12. ROR icon University of California, Los Angeles
  • 13. ROR icon Oregon State University
  • 14. ROR icon Universidade de São Paulo
  • 15. ROR icon California Institute of Technology
  • 16. ROR icon University of Maryland, College Park

Abstract

The Sub-Mesoscale Ocean Dynamics Experiment (S-MODE) is a NASA Earth Ventures Suborbital investigation designed to test the hypothesis that oceanic frontogenesis and the kilometer-scale ("submesoscale") instabilities that accompany it make important contributions to vertical exchange of climate and biological variables in the upper ocean. These processes have been difficult to resolve in observations, making model validation challenging. A necessary step toward testing the hypothesis was to make accurate measurements of upper-ocean velocity fields over a broad range of scales and to relate them to the observed variability of vertical transport and surface forcing. A further goal was to examine the relationship between surface velocity, temperature, and chlorophyll measured by remote sensing and their depth-dependent distributions, within and beneath the surface boundary layer. To achieve these goals, we used aircraft-based remote sensing, satellite remote sensing, ships, drifter deployments, and a fleet of autonomous vehicles. The observational component of S-MODE consisted of three campaigns, all conducted in the Pacific Ocean approximately 100-km west of San Francisco during 2021–23 fall and spring. S-MODE was enabled by recent developments in remote sensing technology that allowed operational airborne observation of ocean surface velocity fields and by advances in autonomous instrumentation that allowed coordinated sampling with dozens of uncrewed vehicles at sea. The coordinated use of remote sensing measurements from three aircraft with arrays of remotely operated vehicles and other in situ measurements is a major novelty of S-MODE. All S-MODE data are freely available, and their use is encouraged.

Copyright and License

© 2025 American Meteorological Society. This published article is licensed under the terms of the default AMS reuse license.

Acknowledgement

This work is a contribution to the S-MODE project, an EVS-3 Investigation awarded under NASA Research Announcement NNH17ZDA001N-EVS3. The success of the S-MODE field campaigns required the dedicated efforts of more than 100 people who supported the data collection at sea and in the air. We thank the captains and crews of the R/V Oceanus, M/V Bold Horizon, and R/V Sally Ride and the pilots and ground crew of the NASA Armstrong B200, the NASA Langley Gulfstream III, and the Twin Otter International aircraft. We thank the staff of the Earth Science Project Office at the NASA Ames Research Center for facilitating many aspects of the project, including the aircraft operations at Ames. We thank two anonymous reviewers for helpful suggestions, and we thank Professor Christine Gommenginger for an extensive and constructive review that substantially improved the manuscript.

Data Availability

All of the S-MODE data are freely available at https://podaac.jpl.nasa.gov/S-MODE or at the DOIs listed in Table 2. The satellite sea surface temperature data shown in Figs. 5 and 7 are available at https://doi.org/10.5067/GHVRS-2PO28 and https://doi.org/10.5067/GHV20-2PO28. The computational code to reproduce Fig. 10 is available through Simoes-Sousa (2024).

Files

Embargoed

The files will be made publicly available on April 25, 2026.

Additional details

Related works

Is supplemented by
Software: 10.5281/zenodo.13942622 (DOI)

Funding

National Aeronautics and Space Administration
NNH17ZDA001N-EVS3

Dates

Submitted
2023-07-14
Accepted
2025-01-21
Available
2025-04-25
Published online

Caltech Custom Metadata

Caltech groups
Division of Geological and Planetary Sciences (GPS)
Publication Status
Published