Monday, December 11, 2023

First hints of nuclear fission in cosmos revealed by models, observations

Fission models find clear fingerprints of nuclear process never before directly observed in stars

DOE/LOS ALAMOS NATIONAL LABORATORY

Neutron Star Merger — IMAGE:
THE MERGER OF TWO NEUTRON STARS IS AMONG THE LEADING CANDIDATE SITES FOR SYNTHESIZING THE HEAVIER ELEMENTS ON THE PERIODIC TABLE THROUGH THE RAPID-NEUTRON-CAPTURE PROCESS. THE IMAGE SHOWS TWO NEUTRON STARS COLLIDING TO RELEASING NEUTRONS THAT RADIOACTIVE NUCLEI RAPIDLY CAPTURE. THE COMBINATION OF NEUTRON CAPTURE AND RADIOACTIVE DECAY PRODUCES SUBSEQUENTLY HEAVIER ELEMENTS. THE ENTIRE PROCESS IS BELIEVED TO HAPPEN IN A SINGLE SECOND.
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CREDIT: CREDIT: LOS ALAMOS NATIONAL LABORATORY (MATTHEW MUMPOWER)

LOS ALAMOS, N.M., Dec. 7, 2023 — The elements above iron on the periodic table are thought to be created in cataclysmic explosions like the merger of two neutron stars or in rare classes of supernovae. New research suggests fission may operate in the cosmos during the creation of the heavy elements. Combing through data on a variety of elements that reside in very old stars, researchers have found a potential signature of fission, indicating that nature is likely to produce superheavy nuclei beyond the heaviest elements on the periodic table.

“People have thought fission was happening in the cosmos, but to date, no one has been able to prove it,” said Matthew Mumpower, a theoretical physicist at Los Alamos National Laboratory and co-author of a paper in Science presenting the research.

Using the latest observations, Mumpower said, the researchers found a correlation between light precision metals like silver and rare earth nuclei like europium. When one of these groups of elements goes up, the corresponding elements in the other group also increase — the correlation is positive.

‘Incredibly profound” evidence of fission

“The only plausible way this can arise among different stars is if there is a consistent process operating during the formation of the heavy elements,” Mumpower said. The team tested all the possibilities and fission was the only explanation that was able to reproduce the trend.

“This is incredibly profound and is the first evidence of fission operating in the cosmos, confirming a theory we proposed several years ago,” Mumpower said. “As we’ve acquired more observations, the cosmos is saying hey, there’s a signature here, and it can only come from fission.”

The research also indicates that elements with an atomic mass (the number of protons plus neutrons) of 260 — heavier than those charted at the high end of the periodic table — may exist.

Mumpower developed the fission models used to predict and guide the observational findings, which were led by study author Ian Roederer of North Carolina State University.

Heavy research

Astrophysicists have long believed heavy elements beyond iron were formed in stellar explosions called supernova or when two neutron stars merged. As the name implies, the latter are composed largely of neutrons, which together with protons form the nuclei of all atoms. Through the rapid-neutron capture process, dubbed the r-process, atomic nuclei grab neutrons to form heavier elements. Whether some grow too heavy to hold together and split, or fission, forming two atoms of lighter but still heavy elements (and releasing tremendous energy) has remained a mystery for a half century.

In a 2020 paper, Mumpower first predicted the distributions of fission fragments for r-process nuclei. A subsequent study led by collaborator Nicole Vassh at TRIUMF predicted the co-production of light precision metals and rare earth nuclei. This co-production of elements like elements ruthenium, rhodium, palladium and silver, and those like europium, gadolinium, dysprosium and holmium, can be tested by comparing the prediction with elemental abundances in a collection of stars.

The new analysis led by Roederer combed through observational data from 42 stars and found precisely the predicted correlation. The pattern provides a clear signature of fission creating these elements and a similar pattern of elements slightly heavier and higher on the periodic table.

“The correlation is very robust in r-process enhanced stars where we have sufficient data. Every time nature produces an atom of silver, it’s also producing heavier rare earth nuclei in proportion. The composition of these element groups are in lock step,” Mumpower said. “We have shown that only one mechanism can be responsible — fission — and people have been racking brains about this since the 1950s.”

From stockpile stewardship to the stars

“At Los Alamos, we developed nuclear fission models because we can’t measure everything that’s relevant for weapons research as part of the Laboratory’s mission,” Mumpower said. The models allow physicists to interpret experiments and fill in data when measurements are lacking. Since the United States halted testing of nuclear weapons in 1992, experimental data on fission has been limited.

The models perform exceptionally well when compared to measured data and thus give credence to their extrapolations where there are no measurements. The nuclear inputs of both short-lived and long-lived species are required for studies of heavy element formation, Mumpower said. Fission yields are products of the process of splitting relatively heavy atoms into lighter ones — the same process used in nuclear weapons and reactors.

The paper: “Element abundance patterns in stars indicate fission of nuclei heavier than uranium.” Science. DOI: 10.1126/science.adf1341

The funding: Laboratory Directed Research and Development program at Los Alamos National Laboratory.

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LA-UR-23-33647

JOURNAL

Science

DOI

10.1126/science.adf1341

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Element abundance patterns in stars indicate fission of nuclei heavier than uranium

ARTICLE PUBLICATION DATE

8-Dec-2023

Advisory panel issues field-defining recommendations for investments in particle physics research

Argonne is set to contribute to the realization of the recommendations, which will shape the next decade of discovery in particle physics

Reports and Proceedings

DOE/ARGONNE NATIONAL LABORATORY

Contributions from Argonne will drive innovation in particle physics and shed light on outstanding mysteries in the field.

Yesterday marked the release of a highly anticipated report from the Particle Physics Project Prioritization Panel (P5), unveiling an exciting new roadmap for unlocking the secrets of the cosmos through particle physics.

The report was released by the High Energy Physics Advisory Panel to the High Energy Physics program of the Office of Science of the U.S. Department of Energy (DOE) and the National Science Foundation’s Division of Physics. It outlines particle physicists’ recommendations for research priorities in a field whose projects — such as building new accelerator facilities — can take years or decades, contributions from thousands of scientists and billions of dollars

The 2023 P5 report represents the major activity in the field of particle physics that delivers recommendations to U.S. funding agencies. This year’s report builds on the output of the 2021 Snowmass planning exercise — a process organized by the American Physical Society’s (APS) Division of Particles and Fields that convened particle physicists and cosmologists from around the world to outline research priorities. This membership division constitutes the only independent body in the U.S. that represents particle physics as a whole.

“With our state-of-the-art facilities and community of dedicated scientists, Argonne’s contributions are shaping the global trajectory of high-energy physics.” — Rik Yoshida, Argonne High Energy Physics Division Director

“The P5 report will lay the foundation for a very bright future in the field,” said R. Sekhar Chivukula, 2023 chair of the APS Division of Particles and Fields and a distinguished professor of physics at the University of California, San Diego. “There are extraordinarily important scientific questions remaining in particle physics, which the U.S. particle physics community has both the capability and opportunity to help address, within our own facilities and as a member of the global high energy physics community.”

The report includes a range of budget-conscious recommendations for federal investments in research programs, the U.S. technical workforce and the technology and infrastructure needed to realize the next generation of transformative discoveries related to fundamental physics and the origin of the universe. For example, the report recommends continued support for the Deep Underground Neutrino Experiment (DUNE), based out of DOE’s Fermilab in Illinois, for CMB-S4, a network of ground-based telescopes designed to observe the cosmic microwave background (CMB), and for the planned expansion of the South Pole’s neutrino observatory, an international collaboration known as IceCube-Gen2, in a facility operated by the University of Wisconsin–Madison.

Researchers at DOE’s Argonne National Laboratory stand at the forefront of high energy physics and are poised to contribute significantly to the advancement of the field over the next decade. They are exploring the fundamental nature of the universe and pioneering innovative technologies with far-reaching implications. In particular, Argonne’s High Energy Physics (HEP) division leverages the laboratory’s suite of multidisciplinary facilities and equipment — including world-class scientific computing capabilities — to further scientific discovery and advance accelerator technology. For example, Argonne’s contributions to key high energy physics collaborations include the design and fabrication of components for DUNE, the development of cutting-edge detectors for CMB-S4 and more.

“With our state-of-the-art facilities and community of dedicated scientists, Argonne’s contributions are helping to shape the global trajectory of high-energy physics,” said Rik Yoshida, director of Argonne’s HEP division. “This report reflects the collective wisdom of the high energy physics community, and we look forward to leveraging our expertise and capabilities here at Argonne to help uncover the mysteries of the universe, drive innovation, inspire future generations of scientists and bolster our nation’s vital role in the future of particle physics.”

“In the P5 exercise, it’s really important that we take this broad look at where the field of particle physics is headed, to deliver a report that amounts to a strategic plan for the U.S. community with a 10-year budgetary timeline and a 20-year context. The panel thought about where the next big discoveries might lie and how we could maximize impact within budget, to support future discoveries and the next generation of researchers and technical workers who will be needed to achieve them,” said Karsten Heeger, P5 panel deputy chair and Eugene Higgins Professor and chair of physics at Yale University.

New knowledge, and new technologies, set the stage for the most recent Snowmass and P5 convenings. “The Higgs boson had just been discovered before the previous P5 process, and now our continued study of the particle has greatly informed what we think may lie beyond the standard model of particle physics,” said Hitoshi Murayama, P5 panel chair and the MacAdams Professor of physics at the University of California, Berkeley. “Our thinking about what dark matter might be has also changed, forcing the community to look elsewhere — to the cosmos. And in 2015, the discovery of gravitational waves was reported. Accelerator technology is changing too, which has shifted the discussion to the technology R&D needed to build the next-generation particle collider.”

The U.S. participates in several major international scientific collaborations in high energy physics and cosmology, including the European Council for Nuclear Research (CERN), which operates the Large Hadron Collider, where the Higgs boson was discovered in 2012. The P5 report recommends that the U.S. support a significant in-kind contribution to a new international facility, the “Higgs factory,” to further our understanding of the

Advisory panel issues field-defining recommendations for US government investments in particle physics research

Activities of the Particle Physics Project Prioritization Panel are supported in part by the American Physical Society’s Division of Particles and Fields

Reports and Proceedings

AMERICAN PHYSICAL SOCIETY

The High Energy Physics Advisory Panel (HEPAP) to the High Energy Physics program of the Office of Science of the U.S. Department of Energy and the National Science Foundation’s Division of Physics has released a new Particle Physics Project Prioritization Panel (P5) report, which outlines particle physicists’ recommendations for research priorities in a field whose projects — such as building new accelerator facilities — can take years or decades, contributions from thousands of scientists, and billions of dollars.

The 2023 P5 report represents the major activity in the field of particle physics that delivers recommendations to U.S. funding agencies. This year’s report builds on the output of the 2021 Snowmass planning exercise — a process organized by the American Physical Society (APS)’s Division of Particles and Fields that convened particle physicists and cosmologists from around the world to outline research priorities. This membership division constitutes the only independent body in the United States that represents particle physics as a whole.

“The P5 report will lay the foundation for a very bright future in the field,” said R. Sekhar Chivukula, 2023 chair of the APS Division of Particles and Fields and a Distinguished Professor of Physics at the University of California, San Diego. “There are extraordinarily important scientific questions remaining in particle physics, which the U.S. particle physics community has both the capability and opportunity to help address, within our own facilities and as a member of the global high energy physics community.”

Deep Underground Neutrino Experiment (DUNE), based out of Fermilab in Illinois, for CMB-S4, a network of ground-based telescopes designed to observe the cosmic microwave background, and for the planned expansion of the South Pole’s neutrino observatory, an international collaboration known as IceCube-Gen2, in a facility operated by the University of Wisconsin–Madison.

The United States participates in several major international scientific collaborations in high energy physics and cosmology, including the European Council for Nuclear Research (CERN), which operates the Large Hadron Collider, where the Higgs boson was discovered in 2012. The P5 report recommends that the United States support a significant in-kind contribution to a new international facility, the ‘Higgs factory,’ to further our understanding of the Higgs boson. It also recommends that the United States study the possibility of hosting the next most-advanced particle collider facility, to reinforce the country’s leading role in international high energy physics for decades to come.

# # #

The American Physical Society is a nonprofit membership organization working to advance and diffuse the knowledge of physics through its outstanding research journals, scientific meetings, and education, outreach, advocacy, and international activities. APS represents more than 50,000 members, including physicists in academia, national laboratories, and industry in the United States and throughout the world.

BNL: Advisory panel issues field-defining recommendations for U.S. government investments in particle physics research

Reports and Proceedings

DOE/BROOKHAVEN NATIONAL LABORATORY

The following news release on the 2023 Particle Physics Project Prioritization Panel (P5) report is based on one issued today by the American Physical Society (APS) with added content specific to the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory. For more information about Brookhaven Lab’s research in particle physics, contact: Karen McNulty Walsh, kmcnulty@bnl.gov, (631) 344-8350. For APS media inquiries, contact Anna Torres, torres@aps.org, (301) 209-3605.

WASHINGTON, D.C.—The High Energy Physics Advisory Panel (HEPAP) to the High Energy Physics program of the Office of Science of the U.S. Department of Energy and the National Science Foundation’s Division of Physics has released a new Particle Physics Project Prioritization Panel (P5) report, which outlines particle physicists’ recommendations for research priorities in the field. The 2023 P5 report was posted online yesterday and was voted on and accepted by HEPAP today.

The 2023 P5 report represents the major activity in the field of particle physics that delivers recommendations to U.S. funding agencies. This year’s report builds on the output of the 2021 Snowmass planning exercise—a process organized by the American Physical Society (APS)’s Division of Particles and Fields that convened particle physicists and cosmologists from around the world to outline research priorities. This membership division constitutes the only independent body in the United States that represents particle physics as a whole.

“We welcome the P5 report recommendations, which define a strong and balanced U.S. particle physics program based on input from the Snowmass community-wide process,” said Brookhaven National Laboratory Director JoAnne Hewett. “Building on our decades of expertise in high energy physics and facility design and operation, we are eager to actively engage and lead in developing, constructing, and operating the next generation of facilities and experiments to explore the Quantum Universe.”

The report includes a range of budget-conscious recommendations for federal investments in research programs, the U.S. technical workforce, and the technology and infrastructure needed to realize the next generation of transformative discoveries related to fundamental physics and the origin of the universe. For example, the report recommends continued support for the high-luminosity upgrades at the Large Hadron Collider (LHC), based in Europe, for the Deep Underground Neutrino Experiment (DUNE), based out of Fermilab in Illinois, for CMB-S4, a network of ground-based telescopes designed to observe the cosmic microwave background, and for the planned expansion of the South Pole’s neutrino observatory, an international collaboration known as IceCube-Gen2, in a facility operated by the University of Wisconsin–Madison.

New knowledge, and new technologies, set the stage for the most recent Snowmass and P5 convenings. “The Higgs boson had just been discovered before the previous P5 process, and now our continued study of the particle has greatly informed what we think may lie beyond the standard model of particle physics,” said Hitoshi Murayama, P5 panel chair and the MacAdams Professor of physics at the University of California, Berkeley. “Our thinking about what dark matter might be has also changed, forcing the community to look elsewhere—to the cosmos. And in 2015, the discovery of gravitational waves was reported. Accelerator technology is changing too, which has shifted the discussion to the technology R&D needed to build the next-generation particle collider.”

The United States participates in several major international scientific collaborations in high energy physics and cosmology, including the European Council for Nuclear Research (CERN), which operates the Large Hadron Collider, where the Higgs boson was discovered in 2012. The P5 report recommends that the United States support a significant in-kind contribution to a new international facility, the ‘Higgs Factory,’ to further our understanding of the Higgs boson. It also recommends that the United States study the possibility of hosting the next most-advanced particle collider facility, to reinforce the country’s leading role in international high energy physics for decades to come.

DOE’s Brookhaven National Laboratory contributes to many of the projects highlighted in the P5 report, including these major efforts:

Brookhaven Lab serves as the U.S. host laboratory for the ATLAS experiment, one of four major detectors at the LHC. ATLAS has opened new frontiers of knowledge about elementary particles and their interactions, including the 2012 discovery of the Higgs boson. Brookhaven Lab scientists contributed to that groundbreaking discovery and subsequent studies of Higgs properties, as well as ATLAS project management and experiment operations. They also run a state-of-the-art computing center for storing and sharing ATLAS data with collaborators around the world. Brookhaven physicists, engineers, and technical staff also helped design and build the magnets that steer the LHC’s beams of protons and other ions into collisions—including magnets enabling drastically increased collision rates for future discoveries.

In addition, the Brookhaven team has proposed ideas for and is dedicated to working closely with international and U.S. partners to develop a Higgs factory and its associated detectors. This facility, as recommended in the P5 report, would create copious numbers of Higgs particles and allow detailed, precision studies of their properties—potentially opening the door to discovering discrepancies between theory and experiment that could reveal new physics. The P5 panel also recommends dedicated R&D to explore a suite of promising future projects, including colliders that can reach even higher energies than Higgs factories. Brookhaven scientists are actively engaged in the development of technologies for one such approach—a machine that could collide particles called muons, heavy cousins of electrons.

Brookhaven Lab is also playing a leading role in DUNE. This Fermilab-based experiment will send beams of elusive subatomic particles called neutrinos hundreds of miles through Earth’s crust to detectors deep underground in South Dakota. Understanding how neutrinos change as they travel may help unravel mysteries about how our universe evolved, including potentially an asymmetry between matter and antimatter that accounts for our universe being composed mostly of matter. Brookhaven physicists and staff helped develop the methods for creating neutrinos, simulations for testing and controlling characteristics of the beam, specialized electronics and other detector materials needed to study key neutrino characteristics, and the software and computational tools that will be used to capture neutrino signals and process vast quantities of data. Brookhaven scientists are leading the design of a third underground detector module for DUNE, highlighted in the P5 report as part of a re-envisioned second phase of this project.

Going beyond the secrets of the matter that makes up our world and its scantly present antimatter partner, Brookhaven scientists seek to explore the unknowns of so-called dark matter and dark energy, which are highlighted among the scientific drivers for new discoveries by the P5 panel and together make up more than 95% of our universe. One tool for this research is a telescope that will be housed at the Vera C. Rubin Observatory high on a mountaintop in Chile. The DOE-funded effort to build the camera for the telescope was managed by SLAC National Accelerator Laboratory. Brookhaven Lab led construction of the camera’s 3.2 gigapixel “digital film”—the biggest charge-coupled device (CCD) array ever built—and will support the telescope’s Legacy Survey of Space and Time (LSST). LSST will be an unparalleled wide-field astronomical survey of our universe—wider and deeper in volume than all previous surveys combined.

Brookhaven Lab is also actively engaged in developing small- and medium-scale facilities and experiments and in building capabilities in machine learning/artificial intelligence, quantum information science, and microelectronics that will help to push the frontiers of discovery in high energy physics with potential benefit for other fields. The Lab is also committed to attracting, building, and supporting a diverse workforce to carry out these ambitious research programs, and to fostering a climate of innovation.

# # #

Activities of the Particle Physics Project Prioritization Panel are supported in part by
the American Physical Society’s Division of Particles and Fields

Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit science.energy.gov.

Follow @BrookhavenLab on social media. Find us on Instagram, LinkedIn, Twitter, and Facebook. Higgs boson.

It also recommends that the U.S. study the possibility of hosting the next most-advanced particle collider facility to reinforce the country’s leading role in international high energy physics for decades to come.

Activities of the P5 are supported in part by the APS’s Division of Particles and Fields.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.

SCI-FI-TEK

Texas A&M Institute part of national effort to harness nuclear laser fusion for limitless energy

The Institute for Quantum Science and Engineering is a major player in advancing laser-driven fusion energy.

Grant and Award Announcement

TEXAS A&M UNIVERSITY

Texas A&M RISE team — IMAGE:
TEXAS A&M’S CORE MEMBERS OF THE RISE HUB INCLUDE IQSE PHYSICISTS (L-R) ALEKSEI ZHELTIKOV, MARLAN SCULLY, ALEXEI SOKOLOV AND ZHENHUAN YI.
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CREDIT: ARASH AZIZI/INSTITUTE FOR QUANTUM SCIENCE AND ENGINEERING

Nuclear fusion, the process that powers the sun, is the ultimate source of energy for all life on Earth. On the sun, deuterium and tritium nuclei combine to produce an alpha particle (the nucleus of a helium atom) and a neutron. The dream is to do the same down here, on Earth, in a controlled manner.

It’s for good reason that harnessing fusion energy is one of the greatest scientific and technological challenges of the 21st century. Fusion requires the fuel to be heated to more than 100 million degrees (10 times hotter than the core of the sun). Practical fusion energy also requires that the burning fuel is kept at these hot temperatures long enough so that energy produced by fusion exceeds the energy required to initiate and sustain the fusion reactions.

One of the two most investigated and promising approaches, Inertial Fusion Energy (IFE), uses powerful lasers, which are fundamental tools in IFE research, to heat a small target containing fusible material. For the first time in history last winter, scientists at Lawrence Livermore National Laboratory’s Ignition Facility achieved a critical milestone in the development of IFE by demonstrating a net target gain with the fusion energy output exceeding the laser energy input on the way to making commercial fusion a success.

On the heels of announcing a $45 million program for IFE fusion energy development in May, the U.S. Department of Energy today (Dec. 7) unveiled a $42 million program establishing three new hubs to advance foundational IFE science and technology. Texas A&M’s Institute for Quantum Science and Engineering (IQSE) is a major player in one of the multi-million-dollar hubs, known as RISE, which will be led by Colorado State University and dedicated to advancing laser-driven fusion energy.

“The RISE hub will become a center of excellence for IFE science and technology to support the DOE’s mission in IFE,” said Dr. Marlan Scully, a University Distinguished Professor and IQSE director.

The DOE investments in IFE science and technology will enable RISE hub researchers to build on the momentum of that 2022 Livermore Lab breakthrough. The RISE hub brings together leading institutions in the U.S. and innovative private fusion companies, along with their unique complementary skills, to synergistically work together to achieve scientific milestones in making fusion energy a commercial reality and to grow the much-needed diverse workforce in fusion.

Researchers from IQSE are joined by scientists and engineers from University of Illinois, Cornell University, Colorado State University, the DOE’s SLAC National Accelerator Laboratory, Los Alamos National Laboratory, the Naval Research Laboratory and three companies: Marvel Fusion, Xcimer Energy and General Atomics.

“The IQSE was built by the visionary Chancellor’s Research Initiative program started by [Texas A&M University System] Chancellor John Sharp,” said Dr. Alexei Sokolov, a professor in the Department of Physics and Astronomy and IQSE associate director. “We look forward to bringing the IQSE expertise in exotic laser physics to bear on the laser-fusion promise.”

The RISE hub is funded by the DOE’s Office of Science, Fusion Energy Science through the DOE’s Inertial Fusion Energy Science and Technology Accelerator Research (IFE-STAR). The RISE hub will combine innovative target concepts with new developments in excimer gas lasers and solid-state laser drivers to open up novel IFE regimes. The hub will also prioritize the involvement of students and workforce development, and university-industry-national laboratory collaborations.

To learn more about research in quantum science and engineering at Texas A&M or the RISE hub, visit iqse.tamu.edu.

Atlantic Ocean near Bermuda is warmer and more acidic than ever, 40 years of observation show

Data spanning 40 years shows changes in the subtropical North Atlantic Ocean near the island of Bermuda, including warming by 1°C

Peer-Reviewed Publication

FRONTIERS

BATS team on BIOS’s research vessel Atlantic Explorer — IMAGE:
BERMUDA ATLANTIC TIME-SERIES STUDY (BATS) TEAM ON BIOS’S RESEARCH VESSEL ATLANTIC EXPLORER
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CREDIT: JEFF NEWTON

Decade-long ocean warming which impacts ocean circulation, a decrease in oxygen levels that contributes to changes in salinification and nutrient supply, and ocean acidification are just some of the challenges the world’s oceans are facing.

In 1988, a comprehensive sustained ocean time-series of observations, called the Bermuda Atlantic Time-series Study (BATS), began at a site about 80 km southeast of the island of Bermuda. There, scientists take monthly samples of the physics, biology, and chemistry of the ocean’s surface and depths. In a new paper published in Frontiers in Marine Science, researchers have now presented the latest findings from this monitoring effort.

“We show that the surface ocean in the subtropical North Atlantic Ocean has warmed by around 1°C over the past 40 years. Furthermore, the salinity of the ocean has increased, and it has lost oxygen,” said author Prof Nicholas Bates, an ocean researcher at the Bermuda Institute of Ocean Sciences, a unit of the Julie Ann Wrigley Global Futures Laboratory at Arizona State University (ASU) and professor in the School of Ocean Futures at ASU. “In addition, ocean acidity has increased from the 1980s to the 2020s.”

Warm, salty, deoxidized, acidic

At the BATS monitoring station, ocean surface temperatures have increased by around 0.24°C each decade since the 1980s. Added up, the ocean is around 1°C warmer now than it was 40 years ago. In the last four years, ocean temperatures have also risen more sharply than in the previous decades, the researchers found.

Not only have the monitored waters gotten warmer, but also more saline at the surface, meaning more salt is dissolved in the water. Like surface temperature, this saltiness has disproportionally increased during the last few years, the newest data showed. “We suspect this is part of the broader, more recent trends and changes in ocean temperatures and environmental changes, like atmospheric warming and having had the warmest years globally,” Bates said.

At the same time, the data indicated that over the last 40 years the amount of oxygen available to living aquatic organisms has decreased by 6%. Acidity values, too, have changed: the ocean is now 30% more acidic than it was in the 1980s, resulting in lower carbon ion concentrations. This can, among other things, affect shelled organisms’ ability to sustain their shells.

“The ocean chemistry of surface waters in the 2020s is now outside of the seasonal range observed in the 1980s and the ocean ecosystem now lives in a different chemical environment to that experienced a few decades ago,” Bates explained. “These changes are due to the uptake of anthropogenic CO2 from the atmosphere.”

Importance of long-time data

Collecting data over extended time periods is important to predict upcoming shifts in conditions. “These observations give a sense of the rate of change in the recent past of ocean warming and ocean chemistry. They provide key indications of future changes in the next decades,” said Bates. “They also are proof of regional and global environmental change and the existential challenges we face as individuals and societies in the near future.”

The monitoring stations providing the data for the present study are just two out of the several long-term sustained ocean time-series sites located throughout the world’s oceans. Stations off Hawaii, the Canary Islands, Iceland, and New Zealand are also key to monitoring long-term oceanic changes. At some of those stations, similar processes have been observed, highlighting the challenges and complexities of understanding the long-term interactions between warming, salinification, and ocean acidification, the researchers said.

Bermuda Atlantic Time-series Study (BATS) team on BIOS’s research vessel Atlantic Explorer

CREDIT

Jeff Newton

Bermuda Atlantic Time-series Study (BATS) team on BIOS’s research vessel Atlantic Explorer

CREDIT

BATS

Bermuda Atlantic Time-series Study (BATS) team members in the lab

CREDIT

Jeff Newton