Nav: Home

UCI scientists analyze first direct images of dissolved organic carbon from the ocean

June 05, 2018

Irvine, Calif., June 5, 2018 - In a first, researchers from the University of California, Irvine - as well as Switzerland's University of Zurich, IBM Research-Zurich and UC Santa Cruz - have obtained direct images of dissolved organic carbon molecules from the ocean, allowing better analysis and characterization of compounds that play an important role in the Earth's changing climate.

Using an atomic force microscopy technique developed by IBM, the team was able to visualize individual atoms and bonds, yielding clues about their persistence in the marine environment. Findings were published today in the American Geophysical Union journal Geophysical Research Letters.

"To understand processes happening on the scale of ocean basins, it is sometimes necessary to view objects that are orders of magnitude smaller," said study co-author Ellen Druffel, professor and Fred Kavli Chair of Earth System Science at UCI. "By seeing with our own eyes the double bonds and rings of dissolved organic carbon molecules, we are better equipped to explain how they remain in the ocean for tens of thousands of years."

The molecules that were imaged were collected by UC Santa Cruz researchers from waters in the northern central Pacific Ocean.

The marine dissolved organic carbon pool, comparable in size to the atmospheric CO2 reservoir, is about 200 times larger than the amount of carbon contained in all the plants and animals on the planet. Because of its complexity, diverse origins and varied reactions to environmental conditions, only about 10 percent of DOC has been characterized.

"We are still trying to figure out how the vast majority of this substance is going to be impacted by the ongoing addition of new CO2 from fossil fuel burning and from increasing temperatures due to global climate change," said co-author Brett Walker, a UCI assistant researcher in Earth system science.

Most DOC near the ocean surface is derived from the remains of recently living phytoplankton. However, radiocarbon dating of DOC in the deep ocean shows it to be much older than expected - by as much as 4,500 years - indicating that a portion of this DOC survives multiple ocean mixing cycles.

Researchers have suggested that the chemical structure of DOC is responsible for its endurance in the environment, and through the atomic force microscopy technique, scientists are now able to see real-space images of the bound atoms in these compounds. The team has found that molecules from the deep ocean frequently exhibit aromaticity, meaning they're flat rings of atoms that are very stable and do not break apart easily.

"These atom-scale visualizations help demonstrate that the old age of small DOC molecules in the deep ocean has to do with their chemical structure, which bacteria do not seem to utilize," Walker said. "This is a crucial finding that will help researchers better understand the cycling of carbon in the oceans and the overall health of our planet's marine environments."
-end-
The work was funded by the University of Zurich, IBM Research-Zurich, the National Science Foundation and the American Chemical Society.

University of California - Irvine

Related Carbon Articles:

The carbon dioxide loop
Marine biologists quantify the carbon consumption of bacterioplankton to better understand the ocean carbon cycle.
Transforming the carbon economy
A task force commissioned in 2016 by former US Secretary of Energy Ernest Moniz has proposed a framework for evaluating R&D on recycling carbon dioxide and removing large amounts of CO2 from the atmosphere.
Closing the carbon loop
Research at the University of Pittsburgh's Swanson School of Engineering focused on developing a new catalyst that would lead to large-scale implementation of capture and conversion of carbon dioxide (CO2) was recently published in the Royal Society of Chemistry journal Catalysis Science & Technology.
An overlooked source of carbon emissions
Nations that pledged to carry out the Paris climate agreement have moved forward to find practical ways to reduce greenhouse gas emissions, including efforts to ban hydrofluorocarbons and set stricter fuel-efficiency standards.
Enabling direct carbon capture
Researchers have developed a solid material that can capture carbon dioxide from the atmosphere, even at very low concentrations.
Development of a novel carbon nanomaterial 'pot'
A novel, pot-shaped, carbon nanomaterial developed by researchers from Kumamoto University, Japan is several times deeper than any hollow carbon nanostructure previously produced.
Unraveling truly one-dimensional carbon solids
Elemental carbon appears in many different forms, including diamond and graphite.
Carbon leads the way in clean energy
Groundbreaking research at Griffith University is leading the way in clean energy, with the use of carbon as a way to deliver energy using hydrogen.
Consumers care about carbon footprint
How much do consumers care about the carbon footprint of the products they buy?
Assessing carbon capture technology
Carbon capture and storage could be used to mitigate greenhouse gas emissions and thus ameliorate their impact on climate change.

Related Carbon Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#514 Arctic Energy (Rebroadcast)
This week we're looking at how alternative energy works in the arctic. We speak to Louie Azzolini and Linda Todd from the Arctic Energy Alliance, a non-profit helping communities reduce their energy usage and transition to more affordable and sustainable forms of energy. And the lessons they're learning along the way can help those of us further south.