Isro's Oceansat-3 captures El Nino's growing fingerprints in Pacific Ocean

India’s Oceansat-3 satellite is offering a striking view of changes unfolding across the Pacific Ocean, detecting what scientists describe as growing fingerprints of the evolving El Nino in 2026.

Data from Isro’s EOS-06, better known as Oceansat-3, shows a reduction in ocean chlorophyll-a concentrations across parts of the Pacific in June 2026 compared with patterns observed during the same month in previous years.

The satellite observations also reveal changes in surface wind patterns, providing a view from space of how the atmosphere and ocean are responding to changing conditions associated with El Nino.

Chlorophyll-a is a green pigment found in phytoplankton, microscopic marine plants that form the foundation of the ocean food chain. The amount of chlorophyll-a present in seawater is often used by scientists as an indicator of phytoplankton abundance and biological activity in the ocean. Oceansat-3 observations show noticeable changes in the central and eastern Pacific. (Photo: Isro)

The latest Oceansat-3 observations show noticeable changes in the central and eastern Pacific, where the highlighted region appears to have lower chlorophyll-a concentrations in June 2026 compared with the patterns captured in June 2024 and June 2025.

Such changes are important because El Nino can disrupt the normal movement of winds and ocean waters across the Pacific.

Under normal conditions, trade winds push warm surface water towards the western Pacific, allowing colder, nutrient-rich waters to rise from the depths in parts of the eastern Pacific. This process, known as upwelling, supports large populations of phytoplankton.

But during El Nino, weakening or changing wind patterns can alter this circulation. Warmer surface waters can spread across large parts of the Pacific, while the supply of nutrient-rich water from below may be disrupted. With fewer nutrients reaching the surface, phytoplankton growth can decline, leading to lower concentrations of chlorophyll-a. Oceansat-3 shows a reduction in ocean chlorophyll. (Photo: Isro)

Oceansat-3 is uniquely placed to track these changes from space. The satellite can monitor ocean colour, winds and other key characteristics of the marine environment, allowing scientists to observe how large-scale climate phenomena affect ocean ecosystems.

The comparison of June observations from 2024, 2025 and 2026 offers a visual snapshot of how the Pacific is evolving.

The changes seen in chlorophyll-a and surface winds provide another reminder that El Nino is not just an atmospheric phenomenon. Its influence extends deep into the ocean ecosystem, affecting tiny marine organisms that support fish populations and broader ocean food chains.

As the 2026 El Nino continues to evolve, observations from Isro’s Oceansat-3 could help scientists track its changing footprint across one of the world's most important oceans.- EndsPublished By: Sibu Kumar TripathiPublished On: Sep 11, 2026 12:50 IST