The collapse of Panama’s seasonal wind-driven upwelling cycle between January and April 2025 marked the first observed disruption in over four decades of records, breaking a long-standing physical pattern according to a research study led by Scientists from the Smithsonian Tropical Research Institute (STRI).

Published 2 weeks ago

Source:  The Watchers

First Observed Disruption in 40 Years of Records

The collapse of Panama’s seasonal wind-driven upwelling cycle between January and April 2025 marked the first observed disruption in over four decades of records, breaking a long-standing physical pattern that supports marine productivity and buffers coastal ecosystems from thermal stress. Patterns like these are tracked because their consistency signals system stability and their collapse may indicate underlying shifts in climate dynamics.

For at least 40 years, the Pacific waters of the Gulf of Panama have experienced a predictable seasonal cycle. Each year between January and April, northerly trade winds drove surface waters away from the coast, allowing colder, nutrient-rich waters to rise from the deep. This upwelling fueled plankton blooms, sustained highly productive fisheries, and provided cooling that shielded coral reefs from thermal stress.

But in 2025, that rhythm was broken. Scientists from the Smithsonian Tropical Research Institute (STRI) documented that the expected drop in sea surface temperatures never occurred. Instead, chlorophyll concentrations — a proxy for phytoplankton productivity — remained low, and the normal seasonal spike in marine life failed to materialize.

The study, published in the Proceedings of the National Academy of Sciences (PNAS), marks the first recorded collapse of Panama’s upwelling system since modern monitoring began.

The missing winds

At the heart of the anomaly lies the Panama wind jet, a channel of northerly winds that funnels through the Isthmus of Panama and drives the mixing of the ocean surface.

Analysis of 40 years of satellite records and 30 years of in situ measurements revealed stark differences in 2025. On average, upwelling began by January 20, lasted 66 days, and cooled waters to around 19°C (66.2°F), with historical extremes as low as 14.9°C (58.8°F). In 2025, however, the onset was delayed until March 4 — 42 days later than usual — and lasted only 12 days. The minimum temperature recorded was 23.3°C (73.9°F), the warmest in the entire record.

When northerly winds did occur in 2025, their speed and strength were comparable to historical values. But they occurred far less often — a 74% reduction in frequency — and relaxation periods were longer, weakening cumulative wind stress across the gulf.

Researchers suggest the anomaly may be linked to the position of the Intertropical Convergence Zone (ITCZ) during the weak 2024–2025 La Niña.

To read the full article:

• Collapse of Panama’s seasonal upwelling cycle signals pattern disruption

For more information:

• Upwelling Failure:  Smithsonian Tropical Research Institute
• Unprecedented Supression of Panama’s Pacific Upwelling in 2025

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Related Links

• Smithsonian Tropical Research Institute
• Proceedings of the National Academy of Sciences of the United States of America

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