For more than two decades, satellites have spotted strange, bright patches
in the icy seas around Antarctica. These glowing swirls of water stood out
in NASA images, yet no one knew exactly what was causing them. Now,
researchers say they’ve solved the puzzle, and the answer lies in the
microscopic life drifting through these remote […]
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#^Antarctica’s Mysterious Ocean Glow Solved After 20 Years of ConfusionFor more than two decades, satellites have spotted strange, bright patches in the icy seas around Antarctica. These glowing swirls of water stood out in NASA images, yet no one knew exactly what was causing them.
Now,
researchers say they’ve solved the puzzle, and the answer lies in the microscopic life drifting through these remote waters. The findings add new insight into one of Earth’s most important carbon stores.
First Clues from Space
Back in the early 2000s, oceanographer Barney Balch noticed something unusual in satellite images of the Southern Ocean. Some areas looked far brighter than the surrounding water.
One region, nicknamed the “Great Calcite Belt”, was known to be filled with coccolithophores, tiny algae with chalky calcium carbonate shells that reflect sunlight. But the satellites also showed another bright band further south, in water so cold that coccolithophores weren’t expected to survive. The mystery persisted for years, hidden by sea ice and cloud cover.
A Risky Voyage South
To find answers, Balch and his team set sail on the research ship
R/V Roger Revelle, heading deep into the Southern Ocean at 60° latitude. They measured the water’s colour, brightness, and mineral makeup from the surface down through multiple depths.
Balch said: “Satellites only see the top several meters of the ocean, but we were able to drill down with multiple measurements at multiple depths. We’ve never had such a complete suite of integrated measurements through the water column in this part of the ocean.”
The Sparkle Makers Revealed
The results showed that in the warmer calcite belt, coccolithophores were still the main source of the glow. But further south, the bright water came from massive blooms of diatoms, algae that build delicate, glass-like shells from silica.
These shells scatter light in a way similar to coccolithophores, but it takes far more diatoms to create the same brightness in satellite images. Surprisingly, the team also found small numbers of coccolithophores living in the colder waters, suggesting they can endure conditions once thought too harsh.
Balch described these icy zones as “seed populations” that help replenish coccolithophores in the calcite belt.
Why It Matters for the Planet
Both coccolithophores and diatoms are key players in locking away carbon. Their mineralised particles sink to the deep ocean, transporting carbon and helping regulate the climate.
The researchers measured particulate inorganic carbon, silica, photosynthesis, and calcification rates. They found the two algae types store carbon differently, hinting that the Southern Ocean’s ecosystem is more complex and adaptable than climate models have assumed.
What’s Next for Satellite Science?
From space, the reflective shells of silica and calcite look almost the same. That makes it tricky for satellites to tell them apart. The team says future studies should combine satellite data with fieldwork to improve accuracy.
Better understanding of these glowing plankton could lead to more accurate climate predictions and improve fisheries management.
A Mystery Finally Solved
After years of speculation, the glow seen from orbit is now explained: it’s the combined shimmer of diatoms and coccolithophores.
As Balch put it: “We’re expanding our view of where coccolithophores live and finally beginning to understand the patterns we see in satellite images of this part of the ocean we rarely get to go to. There’s nothing like measuring something multiple ways to tell a more complete story.”
It’s a discovery that solves an old mystery and opens a new window into the hidden life of one of the most remote and important
oceans on Earth.
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Antarctica’s Mysterious Ocean Glow Solved After 20 Years of Confusion appeared first on
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