The ocean plays a major role in the global carbon cycle. The driving force comes from tiny plankton that produce organic carbon through photosynthesis, like plants on land.
When plankton die or are consumed, a set of processes known as the biological carbon pump carries sinking particles of carbon from the surface to the deep ocean in a process known as marine snowfall. Naturalist and writer Rachel Carson called it the “most stupendous snowfall on Earth.”
Some of this carbon is consumed by sea life, and a portion is chemically broken down. Much of it is carried to deep waters, where it can remain for hundreds to thousands of years. If the deep oceans didn’t store so much carbon, the Earth would be even warmer than it is today.
What still isn’t known
Our study reveals that scientists need to use using a more systematic approach to defining the ocean’s vertical boundaries for organic carbon production and loss. This finding is timely, because the international oceanographic community is calling for more and better studies of the biological carbon pump and the ocean twilight zone.
To compare these studies, researchers need a common set of metrics. For the biological carbon pump, we need to better understand how big this flow of carbon is, and how efficiently it is transported into deeper water for long-term storage. These processes will affect how Earth responds to rising greenhouse gas emissions and the warming they cause.
A Texas A&M-led study analyzed ocean floor sediment cores to provide new insights into the relationship between deep ocean oxygenation and atmospheric carbon dioxide levels in the 50,000 years before the last ice age
Why do carbon dioxide levels in the atmosphere wax and wane in conjunction with the warm and cold periods of Earth’s past? Scientists have been trying to answer this question for many years, and thanks to chemical clues left in sediment cores extracted from deep in the ocean floor, they are starting to put together the pieces of that puzzle.
Recent research suggests that there was enhanced storage of respired carbon in the deep ocean when levels of atmospheric carbon dioxide concentrations were lower than today’s levels. But new research led by a Texas A&M University scientist has reached back even further, for the first time revealing insights into atmospheric carbon dioxide levels in the 50,000 years before the last ice age.
by B. Bruno, May 22, 2020 in ClimateChangeDispatch
Some coral reefs are adapting to warming ocean temperatures by making their own sunscreen in the form of bright neon colors — a strategy that invites coral animals to return to reefs and is seen as a critical adaptation to maintain healthy coral reefs around the world.
In a study published Thursday in the journal Current Biology, researchers at the University of Southampton detail a series of controlled laboratory experiments they conducted at their coral aquarium facility.
In the experiments, “colorful” coral bleaching events cause coral to produce a layer of vibrant sunscreen which encourages the coral animals vital to a mutually beneficial “symbiosis” relationship to return to coral habitats they abandon due to the effects of warming oceans.
The colorful adaptation could prove vital for overcoming the fatal coral bleaching incidents that have threatened coral reefs worldwide.
But the colorful coral bleaching – rather than the white skeleton exposure of common coral bleaching events – is believed to take place due to mild ocean warming or disturbances in their nutrient environment, rather than extreme events.
Colorful bleaching occurred between this past March and April in some areas of the Great Barrier Reef, suggesting some patches of the world’s largest reef system may have better recovery prospects than others.
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