Overview
- ISRO’s National Remote Sensing Centre released satellite analysis on 10–11 September 2026 showing a marked decline in surface chlorophyll-a across parts of the equatorial Pacific in June 2026 compared with June 2024–2025.
- The drop in chlorophyll-a coincided with a weakening and reversal of equatorial surface winds from easterlies to westerlies, which suppressed upwelling that normally brings nutrient-rich deep water to the surface.
- Oceansat-3 (EOS-06) combined Ocean Colour Monitor-3 and scatterometer data to link the wind change with the biological response, demonstrating rapid biophysical coupling and near‑real‑time tracking of ocean ecosystem change.
- ISRO’s observations support WMO and IMD forecasts that El Niño was strengthening through Aug–Oct 2026 and could persist into early 2027, raising the odds of impacts on the Indian monsoon and other regional weather patterns.
- Because chlorophyll responds faster than sea‑surface temperature, the satellite signal serves as an early warning; scientists say continued monitoring of winds, SST, thermocline depth and sea level is needed to track likely effects on fisheries, farming and water resources.