Coral reefs are havens for marine biodiversity and underpin the economies of many coastal communities. But they are very sensitive to changes in ocean chemistry resulting from greenhouse gas emissions, as well as to pollution, warming waters, overdevelopment, and overfishing. Reefs use a mineral called aragonite, a naturally occurring form of calcium carbonate, CaCO3, to make their skeletons.  When carbon dioxide, CO2, from the atmosphere is absorbed by the ocean, it forms carbonic acid—the same stuff that makes soda fizz--making the ocean more acidic and thus more difficult for many marine organisms to grow their shells and skeletons and threatening coral reefs globally.

Ken Caldeira and colleagues have looked at several aspects of coral reef decline. In one study they calculated ocean chemical conditions that would occur under different future scenarios and determined that if we continue on our current emissions path, by the end of the century there will be no areas of the ocean with the chemical properties that have supported coral reef growth in the past. In another study at Australia’s Great Barrier Reef, the researchers found that carbonate accumulation is 44% lower than 40 years ago and that the reef  dissolves  nearly three times more at night than in the 1970s. They suspect that sea cucumbers are a factor in this nightly activity as they feed.

 

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Anna Michalak
September 15, 2021

Washington, DC—Carnegie Department of Global Ecology Director Anna Michalak will be honored with the American Geophysical Union’s Simpson Medal. It will be presented at the organization’s annual meeting in December.

Each year, AGU—a professional society of more than 130,000 experts in the Earth and space sciences—selects two or three members “who have made transformative scientific advances or breakthroughs in the Earth and space sciences, have demonstrated strong leadership, and provided outstanding service to science and society" for this recognition.

Early in her career, Michalak pioneered new approaches for quantifying greenhouse

Artist's concept of hydrogen fuel production. Purchased from Shutterstock.
July 20, 2021

Washington, DC—Designing future low-carbon energy systems to use power generated in excess of the grid’s demands to produce hydrogen fuel could substantially lower electricity costs, according to new work published by Advances in Applied Energy by Carnegie’s Tyler Ruggles and Ken Caldeira.

Renewable energy sources like the Sun and wind have natural variation due to weather patterns—some days are bright and clear, others are overcast; some days are blustery, others are still. This means that renewable power-generating infrastructure needs to be designed with this variability in mind.

To ensure that there is enough power available to meet society

Photograph of an offshore wind farm purchased from Shutterstock.
June 28, 2021

Washington, DC—Location, location, location—when it comes to the placement of wind turbines, the old real estate adage applies, according to new research published in Proceedings of the National Academy of Sciences by Carnegie’s Enrico Antonini and Ken Caldeira.

Turbines convert the wind’s kinetic energy into electrical energy as they turn. However, the very act of installing turbines affects our ability to harness the wind’s power. As a turbine engages with the wind, it affects it. One turbine’s extraction of energy from the wind influences the ability of its neighbors to do the same.

“Wind is never going to ‘run dry’

Close up of a leaf, courtesy of Pixabay
June 9, 2021

Washington, DC—The fact that photosynthesis uses sunlight and atmospheric carbon dioxide to produce sugars has been known for more than a century. But how photosynthesis manages to maintain sugar production through variations in the availability of sunlight and carbon dioxide has remained a mystery until now.

New work published in Photosynthesis Research from Carnegie’s Jennifer Johnson and Joseph Berry reveals that an enigmatic enzyme called the cytochrome b6f complex coordinates the process of capturing sunlight and carbon dioxide.

Through photosynthesis, plants provide the foundation for life on Earth by capturing the Sun’s energy and converting it into

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Anna Michalak’s team combined sampling and satellite-based observations of Lake Erie with computer simulations and determined that the 2011 record-breaking algal bloom in the lake was triggered by long-term agricultural practices coupled with extreme precipitation, followed by weak lake circulation and warm temperatures. The bloom began in the western region in mid-July and covered an area of 230 square miles (600 km2). At its peak in October, the bloom had expanded to over 1930 square miles (5000 km2). Its peak intensity was over 3 times greater than any other bloom on record. The scientists predicted that, unless agricultural policies change, the lake will continue to experience

Until now, computer models have been the primary tool for estimating photosynthetic productivity on a global scale. They are based on estimating a measure for plant energy called gross primary production (GPP), which is the rate at which plants capture and store a unit of chemical energy as biomass over a specific time. Joe Berry was part of a team that took an entirely new approach by using satellite technology to measure light that is emitted by plant leaves as a byproduct of photosynthesis as shown by the artwork.

The plant produces fluorescent light when sunlight excites the photosynthetic pigment chlorophyll. Satellite instruments sense this fluorescence yielding a direct

Ana Bonaca is Staff Member at Carnegie Observatories. Her specialty is stellar dynamics and her research aims to uncover the structure and evolution of our galaxy, the Milky Way, especially the dark matter halo that surrounds it. In her research, she uses space- and ground-based telescopes to measure the motions of stars, and constructs numerical experiments to discover how dark matter affected them.

She arrived in September 2021 from Harvard University where she held a prestigious Institute for Theory and Computation Fellowship. 

Bonaca studies how the uneven pull of our galaxy’s gravity affects objects called globular clusters—spheres made up of a million

Peter Gao's research interests include planetary atmospheres; exoplanet characterization; planet formation and evolution; atmosphere-surface-interior interactions; astrobiology; habitability; biosignatures; numerical modeling.

His arrival in September 2021 continued Carnegie's longstanding tradition excellence in exoplanet discovery and research, which is crucial as the field prepares for an onslaught of new data about exoplanetary atmospheres when the next generation of telescopes come online.

Gao has been a part of several exploratory teams that investigated sulfuric acid clouds on Venus, methane on Mars, and the atmospheric hazes of Pluto. He also

Anne Pommier's research is dedicated to understanding how terrestrial planets work, especially the role of silicate and metallic melts in planetary interiors, from the scale of volcanic magma reservoirs to core-scale and planetary-scale processes.

She joined Carnegie in July 2021 from U.C. San Diego’s Scripps Institution of Oceanography, where she investigated the evolution and structure of planetary interiors, including our own Earth and its Moon, as well as Mars, Mercury, and the moon Ganymede.

Pommier’s experimental petrology and mineral physics work are an excellent addition to Carnegie’s longstanding leadership in lab-based mimicry of the

Johanna Teske became the first new staff member to join Carnegie’s newly named Earth and Planets Laboratory (EPL) in Washington, D.C., on September 1, 2020. She has been a NASA Hubble Fellow at the Carnegie Observatories in Pasadena, CA, since 2018. From 2014 to 2017 she was the Carnegie Origins Postdoctoral Fellow—a joint position between Carnegie’s Department of Terrestrial Magnetism (now part of EPL) and the Carnegie Observatories.

Teske is interested in the diversity in exoplanet compositions and the origins of that diversity. She uses observations to estimate exoplanet interior and atmospheric compositions, and the chemical environments of their formation