The Earth Observing Satellite 6 (EOS-06), also known as Oceansat-3, revealed areas of high oceanic productivity are present in extratropical oceanic zones, equatorial regions.
Elevated levels of Chlorophyll-a, indicating flourishing phytoplankton blooms, are observed from October to December, influenced by wind-driven circulation patterns. Phytoplankton are microscopic, photosynthetic organisms that form the foundation of the marine food web. They play a crucial role in the Earth’s ecosystems as primary producers, converting sunlight into chemical energy through photosynthesis.
Launched by the Indian Space Research Organisation (ISRO), the satellite is transforming our understanding of the global biosphere. This third-generation satellite in the Oceansat series is equipped with advanced instruments, including the Ocean Colour Monitor (OCM-3) and the Scatterometer (SCAT-3), which are providing unprecedented insights into the dynamics of land vegetation and oceanic biological productivity.
The OCM-3 is adept at capturing the global condition of vegetation on land by measuring the Normalised Difference Vegetation Index (NDVI).
This index is crucial for assessing changes in plant health and greenness over vast areas. Over the oceans, the same instrument measures the concentration of phytoplankton chlorophyll, offering a window into the primary productivity of marine ecosystems.
Complementing the capabilities of OCM-3, the SCAT-3 sensor delivers high-resolution data on global ocean surface wind speed and direction. This information is vital for understanding ocean circulation patterns, biogeochemical dynamics, and the genesis of cyclones across the globe.
The National Remote Sensing Centre (NRSC)/ISRO in Hyderabad has been diligently analysing monthly datasets from these sensors. The result is a series of global monthly animations that depict the evolution of NDVI, chlorophyll concentrations, and ocean wind.
These animations reveal the seasonal greening and browning of continents, alongside the dynamic movements of chlorophyll blooms in the oceans, from April to December 2023.
The datat helped in identification high-productivity oceanic regions in extratropical, equatorial, and coastal upwelling zones along the west coasts of major continents, including the Indian subcontinent, South America, and Africa. Notably, phytoplankton blooms, indicated by enhanced concentrations of Chlorophyll-a, peak during the October-December period, driven by wind-induced ocean circulation.
Moreover, the analysis of vector winds has illuminated dominant circulation features such as the convergence of tropical easterlies near the equator, the presence of mid-latitude westerlies, and the seasonally reversing monsoon winds in the Indian Ocean.
Shambhu Kumar is a science communicator, making complex scientific topics accessible to all. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
