Figure from the paper.
The vertical structure of the potential temperature anomalies (a) and practical salinity anomalies in the equatorial oceans (1.5◦S–1.5◦N) for Madden-Julian Oscillation (MJO) phase 3. Red circles in each panel show the longitude of the center of the MJO active convection region. Credit: Robbins et al. [2025], Figure 4
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Oceans

The Madden-Julian Oscillation (MJO) is the dominant weather system in the tropics. It lasts several weeks and changes rainfall, cloudiness, and winds across the tropics. The MJO is well known for triggering an extratropical and global atmospheric circulation response. And recently, several case studies have been conducted on a deeper ocean response to the MJO.

Using 18 years of output from a high-resolution ocean reanalysis product (GLORYS12) largely constrained by Argo data, Robbins et al. [2025] discover intraseasonal anomalies (20-200 days) signals in currents, temperature, and salinity in the tropical oceans down to at least 2,000 meters. They describe that such deep-penetrating structure are equatorial Kelvin waves, which are forced by the MJO in the equatorial Pacific and Indian Oceans. This is one of the first studies to examine the impact of the MJO on the deep ocean and will be beneficial for future investigations into deep-ocean changes.

Citation: Robbins, C., Matthews, A. J., Hall, R. A., Webber, B. G. M., & Heywood, K. J. (2025). The equatorial deep ocean structure associated with the Madden-Julian Oscillation from an ocean reanalysis. Journal of Geophysical Research: Oceans, 130, e2025JC022457.  https://doi.org/10.1029/2025JC022457

—Xin Wang, Editor, JGR: Oceans

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