Massive cuts in federal funding to schools and science agencies, dogmatic calls to eliminate entire research areas, revocations of visas for international students and scholars, and attacks on academic freedom, speech, and the value of education and expertise—all emanating from recent Trump administration actions—are damaging and reshaping U.S. higher education and scientific institutions. Furthermore, the country’s withdrawals from international treaties (e.g., the Paris Agreement) and organizations (e.g., the Intergovernmental Panel on Climate Change and World Health Organization), and its weakening of programs promoting health, environmental protection, cultural exchange, and peace, diminish U.S. leadership and credibility globally and add to instabilities threatening lives, economies, and security around the world.

The surprising speed and breadth of the attacks and changes have left scientists, educators, and others confused, afraid, and grappling with how to respond. The environment of intimidation, uncertainty, isolation, and fear created by the administration has been compounded by the silence or outright capitulation of many leaders and institutions, despite their having firm legal and constitutional protections, in the face of these threats. If sitting Republican senators like Lisa Murkowski (R-Alaska), major universities, law firms, and private companies and foundations are afraid to speak out and defend their values, what can individuals do?

Individuals can organize, and in so doing wield strength in numbers and identify leaders who are well-positioned to raise their voices to push reluctant institutions to act. Within science higher education, senior scientists can and should fill these roles.

Standing Up and Standing Out

The risk calculations for many institutions and individuals in the face of the administration’s swift, illiberal, and authoritarian actions have been clear: It is better to comply than to fight, because fighting risks funding losses, investigations, and lawsuits.

However, as the experiences of some universities, notably Columbia, have demonstrated, submitting to administration demands does not spare institutions from further scrutiny. In Harvard’s case, shortly after the school’s president indicated willingness to engage with the administration about shared concerns, the scope of outrageous demands increased to infringe on its ability to make its own decisions on hiring, enrollment, curriculum, and values, leading the university to sue the administration.

Clearly, the balance of risk between compliance and standing up for core principles (not to mention the rule of law) has shifted. As the leaderships of higher education and science institutions weigh how to respond to this shift, their employees, members, and constituent communities can speak up to shape these responses.

What is needed is courage, solidarity, and an intentional and strategic plan of action. Of course, standing up and standing out are easier said than done, especially considering the very real risks to individuals’ careers, livelihoods, and safety. In science and academia, as elsewhere, these risks are greatest for those most vulnerable: students, early-career researchers, and immigrants and international scholars. Therefore, it is incumbent upon senior colleagues—who have outsize privilege, responsibility, and collective power in universities and professional societies—to lead the way.

Reframing the Message

With social media increasingly fueling the spread of misinformation and disinformation and the corporate consolidation and polarization (both real and perceived) of mass media, strategies used in the past to inform reasoned policy discussions no longer work on their own. Scientists’ rational, detailed, and evidence-based arguments used to be effective in influencing policy, but the current administration and its allies have largely disregarded experts and facts in making major decisions.

With this new reality, the messaging from scientists—especially senior scientists from privileged identities—must change. It must be direct and aimed at resisting ongoing actions that are dismantling U.S. scientific and education enterprises; harming students, universities and colleges, and federal research agencies; and degrading public health, foreign policy, the economy, and the rule of law. Simply put, these actions are leading to death and environmental destruction, and they are endangering the national economy.

The dismantling of federal support for HIV and AIDS research and prevention, for example, “will hurt people, will cause people to die, and will cause significant increased costs to all of us throughout the country,” said a former Centers for Disease Control and Prevention official. The numerous rollbacks of major EPA rules and environmental protections will dramatically degrade air and water quality and irreparably harm public health and ecosystems. And the cuts to scientific research will directly affect our ability to advance medical, energy, transportation, space, communication, and infrastructure innovations, undermining the country’s economic strength.

Influencing Institutional Leaders

In addition to speaking simply and clearly about the realities of such threats, scientists must come together within their own and across institutions to form united fronts. Senior scientists should be at the vanguard of these fronts, using their influence to protect students and more vulnerable colleagues, U.S. citizens, and international scholars alike.

They should demand that their institutional leaders uphold core values of higher education and science, including inclusion, international cooperation, and ethical and evidence-based research. They should demand that these leaders strengthen mutually beneficial ties among universities and professional societies, urging them, for example, to join mutual defense alliances such as the recently proposed coalition among Big Ten universities and to sign on to the American Association of Colleges and Universities’ “Call for Constructive Engagement” that rebuked the administration’s attacks. And they should demand that instead of capitulating, their institutions bring and support litigation against attempts to suppress academic freedom, free speech, and freedom of association; to unlawfully cancel grants and revoke visas; and to infringe on universities’ independence to develop their own curricula and academic policies. After all, executive orders are unilateral directives, not laws or legislation.

Furthermore, institutions should provide free legal counsel to imperiled international students and researchers and speak loudly and publicly about the meaning and value of academic freedom, the power of diverse and inclusive communities in driving societally valuable innovations, and the incredible returns of investing in modern research universities.

Though these demands are made of our institutional leaders, senior scientists can also act on their own initiative to help defend the higher education and scientific communities and their work from attacks meant to discredit and marginalize them.

Acknowledge and Activate

What can these scientists do? For starters, they can keep up-to-date about the shifting landscape of relevant federal, state, and institutional policies and responses. Many timely resources can help with this. I joined the chapter of the American Association of University Professors (AAUP) at the University of Michigan in Ann Arbor, where I work, for this purpose.

Senior scientists can support early-career colleagues and students by helping them, in turn, stay informed of policy developments, by actively listening to and understanding their concerns, and by providing opportunities for career and community networking and professional development during these uncertain times. Universities frequently offer mentoring resources and tool kits that can help, and programs such as AGU’s Mentoring365 enable connections within and across peer groups. They can also support each other across campuses, and seek allies in other disciplines, recognizing that attacks on the arts, humanities, and STEM (science, technology, engineering, and mathematics) fields are all connected.

Further, scientists should be contacting and meeting with local, state, and federal elected officials. Scientists should use those meetings to convey the impacts of funding cuts and attacks on students, scholars, research, and innovations, citing real examples from their home institutions. At the University of Michigan, for example, scores of grants and contracts (including two of my own) have been canceled or not renewed, either because they were not compliant with administration ideology on DEI (diversity, equity, and inclusion), health equity, or environmental justice, or because of agency program eliminations and budget cuts. These cuts have directly halted student research experiences and led to layoffs and withdrawals of graduate admissions offers.

Although local and state officials cannot directly change federal policy, scientists can help focus their attention on the local impacts of federal actions. Further, these leaders’ concerns often carry a different weight within political decisionmaking. A federal congressperson may respond differently to a state senator from their own political party than they would to the concerns of 10 scientists.

Senior scientists can also work with their professional societies and organizations to file litigation against unjust actions, and provide programming (e.g., career counseling) and financial support (e.g., waived conference registration fees) for students and colleagues directly affected. And if needed, they can push their professional societies to take stronger stances. The powerful statement by the American Academy of Arts and Sciences offers a model that every nonprofit professional society should emulate. Even if institutions or societies have adopted neutrality statements, or are nonprofits prohibited from lobbying activities and whose memberships have diverse views, there is clear rationale to speak out and act against policy changes that directly affect their missions.

In short, senior scientists must acknowledge the severity of the threats to the scientific and higher education communities from the administration’s actions and activate to support local and national efforts to counter the threats. Together with the leaderships of their institutions and professional societies, they must defend these communities—particularly their more vulnerable members—and the value and integrity of the work they do. The stakes are high: Lives and careers are being jeopardized, and brilliant scientists are being driven away. We must act to preserve the American partnership that created diverse, federally supported research universities before the damage is permanent.

Author Information

Mark Moldwin (mmoldwin@umich.edu), University of Michigan, Ann Arbor

Citation: Moldwin, M. (2025), Senior scientists must stand up against attacks on research and education, Eos, 106, https://doi.org/10.1029/2025EO250181. Published on 9 May 2025 2025.

This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s).

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Choose Your Own Geoscience Adventure

The changes to teaching and learning at colleges and universities that many of us thought would last a few weeks in the spring of 2020 have turned into more than a year’s worth of disruptions. For both students and instructors, these disruptions have interrupted, set back, and, in some cases, irrevocably altered personal and professional lives and relationships, and they have severely strained mental—if not also physical—health.

The forced adaptations have also exposed unresolved and problematic realities in academia that long predate the pandemic, leading to difficult discussions but also creating welcome space for fresh perspective and growth. We reflect here on some of the negative and positive outcomes we’ve seen over the past year, as informed by our own experiences with students and colleagues.

Displaced and Disrupted

Pandemic disruptions to teaching, learning, and life took many forms. When colleges and universities instituted social distancing measures and turned to remote instruction, undergraduate students were rushed off campus. Many returned to family homes, where they were isolated from friends and lost the autonomy they had been cultivating while living independently. Subjected once again to household rules set by parents or other guardians, these students were essentially infantilized during the pandemic. Yet their institutions expected them to be mature adults and to keep to academic schedules as if nothing had changed. Many of our students, as they relayed to us, felt untethered, overwhelmed, and unable to sift through endless directions and FAQ pages from the schools about rapidly evolving pandemic protocols.

Meanwhile, graduate students lost access to facilities integral to their research, from offices to laboratory analytical equipment to field sites. They were expected to teach and learn online skillfully and to adjust without complaint. Their support networks became frayed as colleagues and mentors dispersed from campus.

For some students, the burdens of these changes were especially acute. We both work at large public institutions, where up to one quarter of our students are the first in their family to attend college and up to 20% are international students. These students’ lives were suddenly and disproportionately upended by displacement, underresourcing, isolation, and, in some cases, repatriation.

At the same time students were doing their best to adjust to the new landscape of higher education, so too were faculty and instructors. Among other challenges, individuals had to adapt in-person course materials, teaching styles, and mentoring duties to fully remote environments on the fly. They had to reconfigure research programs to account for pandemic restrictions. And many faced the added complexity of maintaining professional responsibilities while simultaneously caring full-time for loved ones also displaced from their usual routines. We, like many of our colleagues, often reminded ourselves of the phrase “I am not working at home because of the pandemic; I’m at home due to the pandemic—trying to work.”

Remote teaching brought important changes to student-teacher relationships. Prior to the pandemic, we took for granted the simple joys of greeting students when they arrived at class, helping facilitate discussions around our course content, and getting to know students—their career aspirations, their challenges, and their interests. During the pandemic, we have still held classes and office hours, conducted research, and mentored students—but all virtually. Although Zoom and other such tools are amazing technological innovations that have enabled us to perform our work, they tend to dull the emotional and personal connections that face-to-face contact builds.

Emotional Tolls

Although we hope the vaccines developed to protect against COVID-19 will enable a full return to prepandemic life, the experiences we have shared with students and colleagues throughout the pandemic will remain with us, with some hanging as shadows over the coming years of social and economic recovery. Of course, these experiences have also been influenced strongly by events not directly related to the pandemic, such as the attack on the U.S. Capitol and the murders of George Floyd and others as well as the large-scale demonstrations in support of racial justice. Among other effects, these events have brought heightened attention to systemic racism and injustice in many institutions, including our own, and have added substantially to the emotional and physical stress of the pandemic for many in academia, particularly people of color.

Against this backdrop, the pandemic has forced academia to grapple with declining mental health among students and faculty, a trend that began well before 2020 [National Academies of Sciences, Engineering, and Medicine (NASEM), 2021a], particularly in science. Research has shown that in many cases, student learning and grades have improved during the pandemic, although these successes came with emotional costs. Prior to COVID-19, in spring 2019, three out of five college students reported experiencing extreme anxiety, and two out of five reported debilitating depression sometime in the preceding 12 months [American College Health Association, 2019]. In the past academic year, the trends in mental health have drastically worsened [NASEM, 2021a] as students have been deprived of the ability to engage with others; to participate in educational extracurricular activities and travel; and to pursue many professional and personal opportunities such as internships, fieldwork, and spring break. Moreover, many of our students have contracted COVID-19, including students in our research groups and in all of the courses we teach, and those who have not tested positive themselves have still had to deal with the virus affecting friends and family.

Faculty, who have long faced tremendous dysfunction in career expectations and work-life balance—especially for early-career faculty, women, and faculty of color—are also depressed, stressed, and burned out [NASEM, 2021b]. As of last fall, almost 9 out of 10 faculty surveyed agreed (33%) or strongly agreed (54%) that our jobs had become more difficult, 40% reported considering leaving the profession, and 48% of that number were early-career faculty. These stark figures partly reflect the emotional toll of taking on roles as informal, mostly untrained, and often poorly equipped mental health counselors to our students, which left faculty and students at risk.

Faculty members became critical elements in the support networks for many of our students, requiring us to share additional empathy and to develop new ways to connect, in virtual environments, with students suffering emotionally and physically. We also became critical conduits for sharing university-wide information, from academic schedule changes and new grading modalities to rent relief options in the community and plans for packing up dorms and apartments. This role required keeping up to date with frequently changing policies and information so we could share it clearly and quickly.

Make no mistake: This emotional work, called affective labor, is difficult—and it is labor indeed. Affective labor is the work associated with managing one’s own feelings when things are going to pieces around you—when others are upset, frightened, or angry. We put ourselves through secondary trauma in supporting our students, colleagues, family, and friends while trying to carry on ourselves and maintain our own well-being.

Because this care work has been borne mostly by women faculty and faculty of color, resulting impacts on careers—such as decreased research productivity and delayed promotions—will fall disproportionately on these groups and will affect academia for years to come.

Lights in the Tunnel

Despite the disruptions and added affective burdens placed on students and faculty throughout the pandemic, there have been some positive outcomes to emerge. We speak here not about the learned benefits of technology or of asynchronous learning and other pedagogical adaptations but, rather, of the emotional rewards we experienced during this time.

Students and faculty members bonded like teammates in spring 2020. We struggled with the technology needed for remote instruction, our students struggled with the technology, and we all learned it together. When pets, children, and spouses made visits to our home offices, our students loved seeing us get rattled, because it reminded them of our humanity. They started sharing their pets on screen, and everyone enjoyed getting to know more about one another. Students also shared the stresses of their family situations. We made as many adjustments as we could to help them get through each semester, including changing deadlines, amending or canceling assignments, and just simply listening to them.

Not surprisingly, the camaraderie waned as the pandemic progressed, and by the end of the spring 2021 semester, many students were exhausted from remote learning and the loss of the college environment. This transition only increased the emotional workload for faculty and led to increased frustration and fatigue.

Nonetheless, the door to richer teaching and learning experiences has been opened during the pandemic. Faculty have opportunities to embrace the role we play in helping students transition to adulthood and to recognize that course content is not the only currency of value to our students. It humanizes us, and our students, when we take the time to get to know them, to open up ourselves, and to admit to the stresses, emotions, and frustrations with which we struggle.

Faculty in science, technology, engineering, and mathematics (STEM) disciplines have historically taken a pass on doing this sort of emotional work. In our classrooms, we traffic in content—observations, calculations, and hypotheses—not in personal stories and cultural issues. We have often told ourselves, “Science doesn’t see color or gender,” “I couldn’t possibly deal with racism because I teach science,” and “Science is not driven by society,” although in each case there is much evidence to the contrary. If we have learned nothing else from the pandemic, we have seen that both we and our students value a more personal approach to instruction.

Outside the classroom as well, there are many things that faculty can do to help themselves and each other: foster, renew, and make new connections with mentors, advisers, colleagues, friends, and family; and develop or continue activities that provide a sense of community among instructors. At the University of Michigan, for example, faculty have set up monthly teaching circles—held virtually during the pandemic—at both departmental and college levels. Teaching has often been a lonely endeavor and not the topic of hallway discussions at research universities, so these regular opportunities to meet have enabled needed support networks and chances to learn and grow professionally. The AGU Education section also provides resources and a venue in which to find, connect with, and support other Earth and space science faculty, both professionally as colleagues and personally as friends.

The affective labor of connecting more deeply with students and colleagues takes time and energy—but it matters. It can make a big difference in helping STEM faculty and their students recover from the myriad disruptions of the pandemic and reshape what postsecondary teaching and learning look like.

References

American College Health Association (2019), American College Health Association-National College Health Assessment II: Spring 2019 reference group executive summary, 19 pp., Silver Spring, Md., https://www.acha.org/documents/ncha/NCHA-II_SPRING_2019_US_REFERENCE_GROUP_EXECUTIVE_SUMMARY.pdf.

National Academies of Sciences, Engineering, and Medicine (NASEM) (2021a), Mental Health, Substance Use, and Wellbeing in Higher Education: Supporting the Whole Student, 212 pp., Natl. Acad. Press, Washington, D.C., https://doi.org/10.17226/26015.

National Academies of Sciences, Engineering, and Medicine (NASEM) (2021b), Impact of COVID-19 on the Careers of Women in Academic Sciences, Engineering, and Medicine, 194 pp., Natl. Acad. Press, Washington, D.C., https://doi.org/10.17226/26061.

Author Information

Tanya Furman (tfl3@psu.edu), Pennsylvania State University, University Park; and Mark Moldwin, University of Michigan, Ann Arbor

Citation:

Furman, T., M. Moldwin (2021), Higher education during the pandemic: Truths and takeaways, Eos, 102, https://doi.org/10.1029/2021EO160171. Published on 25 June 2021.

Text © 2021. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

When I became Editor in Chief of Reviews of Geophysics in October 2009, I decided to do something “old school” and read every paper that we handled. I was fortunate to have had the opportunity to talk with two earlier incumbents—Alex Dessler (1970-1974) and Andy Nagy (1980-1984)—who were not only the Editor in Chief, but at the time the only editor for the journal. They single-handedly were responsible for all the papers submitted from across the entire spectrum of Earth and space science disciplines that AGU membership spans. Since Reviews generally publishes 24 or so papers per year, I thought that I could be as “hands-on” as these former editors.

Besides learning much more about the breadth and importance of the science that the AGU community studies, I learned that my AGU colleagues are awesome. All of the authors of review papers that were published in the last eight years have made tremendous impact on our disciplines. Their review papers not only synthesized the current understanding but also helped resolve controversies and define future directions of the field. A significant fraction of Reviews of Geophysics papers are in the top 1 per cent of highly cited papers, clearly indicating the quality of the author teams’ contributions and impact [Moldwin et al., 2017].

A requirement to write an excellent review paper is a large and talented pool of referees that are willing to commit significant effort providing extensive, timely and helpful feedback to the author teams and to the Editorial Board. Their comments not only helped authors to make the reviews more concise and well structured, but also helped them provide context to the broader geoscience community.

The role of the editorial board (Fabio Florindo, Gregory Okin, Alan Robock, Eelco Rohling, Bayani Cardenas, Annmarie Carlton, Kate Huihsuan Chen, Michel Crucifix, Andrew Gettelman, Alun Hubbard, Tomoo Katsura, and Thomas Painter) in identifying author teams and referees to work with them was also crucial to the success of the journal. The Editorial Board has shown tremendous dedication to assisting author teams, referees, and each other in making outstanding decisions. During our tenure, we handled only a few papers that were problematic in one way or another and I know that the editors made thoughtful, fair and defensible decisions.

Assisting the Editorial Board were incredible AGU Editorial Assistants and Publications staff (Julie Dickson, Rochelle Odon, Jenny Solecki, Pam Calliham, Rebecca Knowlton, Graciano Petersen, Edith Judd, Zach Stahly, Randy Townsend, Jeanette Panning, Lorraine Hall-Petty, Indrani DasGupta, Victoria Forlini, Sara Young, Paige Wooden, Bill Cook, Jenny Lunn and Brooks Hanson). They provided clear communication channels between the authors, referees, editors and Wiley production staff. As is true in so many areas of science, without highly professional, competent and friendly staff support, nothing would get done.

I am very grateful for all the support and collegiality offered to me as I served in this role. I am confident that the new Editor in Chief, Fabio Florindo, will lead Reviews of Geophysics well into the future.

At the AGU Fall Meeting in New Orleans please join me in thanking the AGU publication staff, editors, authors and referees for all they have done for our community. When you are standing in a beer or coffee line, thank the person next to you, since they probably have been involved with some aspect of the publication process – as an author, as an editor, or a referee. Our future depends on our continued unselfish cooperation in research and our willingness to assist each other in communicating our science.

—Mark Moldwin, Editor in Chief, Reviews of Geophysics, and Department of Climate and Space Sciences and Engineering, University of Michigan; email: mmoldwin@umich.edu

Citation:

Moldwin, M. (2017), An “old school” approach and a community effort, Eos, 98, https://doi.org/10.1029/2018EO086711. Published on 15 November 2017.

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After two decades of incredible exploration, the Cassini Mission to Saturn is now over. The Cassini spacecraft has beamed back images and vast amounts of data, first from its flybys of Earth, Venus and Jupiter, then from 13 years spent circulating the ringed planet and its moons, as well as insights from landing the Huygens probe on the surface of Titan, the largest moon.

According to NASA, 3948 science papers have been published as a result of the mission. A search for papers in AGU journals with Cassini mentioned in the abstract published since the mission started in 1997 generated more than 750 results across 6 different journals. We are very proud that AGU has played a significant role in publishing some of the important findings from the mission. We invited some of the editors to reflect on papers published in their journals and how they have contributed to our scientific understanding. A special collection of all the papers highlighted below can be found here.

Mike Liemohn, Editor-in-Chief, Journal of Geophysical Research: Space Physics

There are over 400 papers in JGR: Space Physics with Cassini mentioned in the abstract, so it is a rather difficult task to pick out just a few to highlight. Since one measure of impact is citations, here are a few reflections on the four most-cited Cassini papers.

We knew so little about Saturn’s magnetosphere before Cassini that the initial papers published soon after orbit insertion were all “discovery studies” of never-before-seen phenomena. Only one of those initial papers makes the list, though; the other three came a few years later, when the first statistical analyses could be conducted.

In poll position, the most-cited paper is Schippers et al. [2008], who presented an analysis of the electrons seen by several instruments. A complementary study of the ion populations in Saturn’s magnetosphere, second on the most-cited list, was conducted by Thomsen et al. [2010]. In addition to the survey results describing the charged particles environment around Saturn, these studies also include detailed methodologies for handling tricky instrumentation obstacles: sensor intercalibration in the first case and moments calculations in the second.

The third most-cited paper, also related to the plasma environment of Saturn, is Cowley et al. [2005], who examined Cassini measurements in the magnetosphere in relation to Hubble Space Telescope observations of Saturn’s aurora. It is an elegant explanation of spiral auroral structures being related to magnetic reconnection behind the planet in the magnetotail and the subsequent convection due to Saturn’s fast rotation. It also demonstrated that solar wind dynamic pressure controls this magnetotail reconnection, rather than the direction of the interplanetary magnetic field, as is the case at Earth.

The fourth most-cited Cassini paper in the journal is about the famous question of the planetary rotational period [Kurth et al., 2008]. Much of the sphere that we call Saturn is a fluid, not a solid, and the “surface” that we see is really just the top of a particular cloud layer. This allows for something called differential rotation, in which different latitudes rotate at different rates, making it very difficult to determine a definitive and single planetary rotation rate.

One manifestation of this is in radio emissions from the auroral regions of Saturn, which exhibit a large-scale amplitude modulation that is very close to the nominal rotation period of 10.7 hours. This “daily” wax and wane of the radio emission slowly varies with time, and even more mysteriously, has different periods in the northern and southern auroral regions. This paper defines a Saturn longitude system timed with the radio emission modulations.

Mark Moldwin, Editor-in-Chief, Reviews of Geophysics

As mentioned above, one of the most interesting aspects of the magnetosphere of Saturn that the Cassini Mission observed was that there are modulations in charged particles, magnetic fields, energetic neutral atoms, radio emissions, motions of the plasma sheet and magnetopause and even in the rings with periodicities near the rotation period of the planet of about 10.7 hours. However, these periodicities change by about 1 per cent over time scales of a year or longer and are different in the northern and southern hemispheres. The highest-cited paper in Reviews of Geophysics related to Cassini is Carbary and Mitchell [2013] who reviewed the observations and the many models that have struggled to explain these puzzling periodicities.

Elizabeth P. Turtle, Associate Editor, Journal of Geophysical Research: Planets

In over 13 years of exploring the Saturnian system, the Cassini-Huygens mission has completely revolutionized our understanding of Saturn, its magnetosphere, rings, and moons large and small.  Over 70 manuscripts published in JGR-Planets to date illustrate the remarkable breadth and depth of the scientific discoveries that Cassini-Huygens has made possible, covering topics from the winds and vortices of giant Saturn itself [Vasavada et al. 2006] to diminutive Enceladus’ powerful cryovolcanic eruptions [Howett et al. 2011] and interior dynamics [Barr 2008].

Developments in our understanding of Titan have had particular impact. In fact, eighty percent of the twenty most-cited JGR-Planets papers related to Cassini-Huygens present Titan results. Some of these wide-ranging papers address the behavior of the atmosphere [Teanby et al. 2008, Yelle et al. 2008, Mueller-Wodarg et al. 2008, Cui et al. 2012].

Others examine the tremendous level of complexity in the chemistry occurring on Titan revealed by in situ compositional measurements by Huygens [Niemann et al. 2010] and Cassini [Mandt et al. 2012, Westlake et al. 2012], combined with modeling [Vuitton et al. 2008, Horst et al. 2008].

They also trace the long-awaited unveiling of Titan’s surface, documenting the diversity of its geological structures and processes [Barnes et al. 2007, Le Mouelic et al. 2008, Mitri et al. 2010], materials [Clark et al. 2010], methane lakes and seas [Hayes et al. 2010], and potential subsurface exchange via cryovolcanism [Lopes et al. 2013].

Although the Cassini-Huygens mission is at an end, the wealth of data it has gathered will continue to fuel research on the Saturnian system and broader comparative planetology studies for decades to come.

—Jenny Lunn, Director of Publications, American Geophysical Union; email: jlunn@agu.org; Mike Liemohn and Mark Moldwin, Department of Climate and Space Sciences and Engineering, University of Michigan; Elizabeth P. Turtle, Johns Hopkins Applied Physics Laboratory

Citation:

Lunn, J.,Liemohn, M.,Moldwin, M., and Turtle, E. P. (2017), Cassini’s legacy in print, Eos, 98, https://doi.org/10.1029/2018EO082295. Published on 20 September 2017.

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Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

The March for Science is appropriately being held this weekend on Earth Day 2017. The broad theme for the March is “Science is Essential,” and this is applicable also to Earth Day. It may seem that with our growing cities, air conditioning, modern infrastructure, and energy-enabled amenities, we can be more isolated from our environment and less dependent on Earth than our ancestors, but the opposite is true: We are more intimately connected than ever before. Many aspects of modern society depend critically on rich real-time data and sophisticated models about all aspects of our planet and its space environment. Growing populations and development are taxing natural resources and increasingly altering Earth’s land, ecosystems, atmosphere, ice sheets, rivers, and oceans on a global scale. Globalization makes our societies, including the most developed ones, more sensitive to disruptions. These interdependencies make research in the Earth and space sciences critically important for society.

A collection of essays and other recent Special Collections across the American Geophysical Union journals illustrate, celebrate, and illuminate these deep connections. Three broad and generally underappreciated themes emerge across this collection. These themes have important implications in the context of recent U.S. and international political developments.

The first theme is that the notion that “basic” or “curiosity-driven” research is distinct from “applied” research is increasingly an anachronism. Most of the cutting-edge research being conducted by Earth and space scientists has direct relevance to society. This relevance is not new but is more extensive and broadly connected than in the past. Geologic research has long been a key contributor to energy and mineral exploration. But research motivated by curiosity about how the Earth works has also led to important resource discoveries. For example, deep ocean drilling to improve understanding of the ocean crust and sediments in the Gulf of Mexico in the late 1960s led to the discovery of vast oil resources.

Today, the connections are broader. Businesses, societies, and economies operating from local to global scales are critically dependent on real-time data about our planet, increasingly at very fine spatial and temporal scales. In turn, these data feed improved models that both address new research questions and provide operational data and forecasts for societal decisions, from governments to individual farmers and shippers. Examples abound. Detailed real time mapping of ocean currents helps us understand how the oceans mix, directly helping companies save fuel in ocean transportation, trade, fishing, and recreation. Understanding subtle changes in Earth’s rotation tells us about Earth’s core and history but also improves GPS signals on which we increasingly rely. A huge amount of global data of great variety, including from citizen science as well as research into numerical methods and statistics, is necessary to provide ever more accurate weather and water-supply forecasts, yielding major economic benefits, and protecting people, crops, and ecosystems. Observations of the sun and of our near-space environment are used to protect our electrical grids, satellites, and airline passengers as well as to improve the fidelity of GPS signals. Testing of sensors on other planets has improved or led to new satellites that provide key data on Earth. And Earth and space science information provide critical insights for addressing many health concerns, from air pollution to human and agricultural pandemics.

The second theme is that these current capabilities have developed, and are critically dependent on, international collaborations, cooperation, and funding. These collaborations include scientists, of course, but they also involve governments and businesses. Global data for a global economy requires global research and data-collection efforts, which require global collaboration and cost-sharing. In addition, it is clear that understanding of local weather requires rich global data; snowfall in the Sierra Nevada is influenced by dust entrained in the atmosphere from Asia and Africa. Understanding the course of one volcanic eruption or earthquake improves understanding of the next one elsewhere in the world. The costs of research and infrastructure, including satellites, have increasingly been shared worldwide. The U.S. economy, as that of every country, greatly benefits from this global research collaboration and shared financing for Earth observations. These collaborations are needed to maintain and expand our global observing effort and the economic and security benefits that it enables.

The third theme, already introduced, is the inclusion of rich data from monitoring all parts of Earth’s processes and its environments (present and past) into sophisticated models that are used both to understand Earth’s processes and to inform critical societal decisions. This understanding is regularly included in engineering models used to mitigate hazards or design better structures. Likewise, such models provide weather forecasts, help predict water supply and coastal erosion, prepare cities and regions for natural hazards and climate change, and help coordinate responses to disasters in real time. Improvements to these models depend on global data, including data whose collection was originally motivated by scientific research.

Although there has been great progress over several decades in using research in Earth and space science for the benefit of humanity, the collection of essays also highlights many areas where further progress is both possible and needed. These include new applications, constraining uncertainty, and improving models and forecasts. The authors of these essays also discuss how Earth and space scientists can better communicate both what we know and don’t know and where further improvements are within reach. The Earth complex, and the desire for more effective understanding and communication, is strong.

Two critical threats have emerged to the societal benefits provided by Earth and space science. The first is increasing nationalistic tendencies worldwide that threaten the international collaborations that have facilitated the development of global research, funding, and data collection. Our understanding of Earth processes and current global capabilities – and the economic and societal benefits – have developed directly because scientists and students have been allowed to interact internationally, conduct research worldwide, share global observation platforms, secure temporary and permanent positions in other countries, and attend international conferences. Restricting this exchange will directly harm existing capabilities and limit future scientific advances. Because this international cooperation is critical to understanding the Earth as a system, the Earth and space sciences are particularly vulnerable to such restrictions.

The second threat is proposed funding cuts in major science agencies in the United States and elsewhere. These cuts will do the most harm in two critical areas: collecting and interpreting important data, and training and engaging new scientists. The infrastructure supporting scientific data, especially relating to our planet, is fragile and needs new support for long-term preservation and connectivity, as well as broader availability and sharing of data given its critical economic and scientific role. We need better and more systematic data about our impact on the environment, not less. Instead, U.S. agencies are facing the prospect of substantial cuts, spurring efforts to “save the data.” As Harold Varmus noted in commenting on the proposed cuts to the NIH budget, the cuts are likely to fall most heavily on the youngest aspiring scientists. The proposed cuts send a message that these jobs are not valued, and that the resources needed to support both the long-term collection of data and the training of the next generation of scientists are not guaranteed.

Earth Day and the March for Science both celebrate the increasingly valuable benefit of Earth and space science research for society. It is also an opportunity to appreciate how these impacts are rooted in a very deep understanding of our planet and its past, present, and future environments. This connection between science and society can and should be made even stronger, for even greater benefit to humanity.

—Brooks Hanson, Director Publications, AGU; email: bhanson@agu.org; Jenny Lunn, Assistant Director, Publications, AGU; Ben van der Pluijm, Editor-in-Chief, Earth’s Future; John Orcutt, Editor-in-Chief, Earth and Space Science; Rita Colwell, Editor-in-Chief, GeoHealth; Susan Trumbore, Editor-in-Chief, Global Biogeochemical Cycles; Thorsten W. Becker, Editor-in-Chief, G-Cubed; Noah Diffenbaugh, Editor-in-Chief, Geophysical Research Letters; Robert Pincus, Editor-in-Chief, JAMES; Mike  Liemohn, Editor-in-Chief, JGR: Space Physics; Uri ten Brink, Editor-in-Chief, JGR: Solid Earth; Peter Brewer, Editor-in-Chief, JGR: Oceans; Minghua Zhang, Editor-in-Chief, JGR: Atmospheres; Steven A. Hauck II, Editor-in-Chief, JGR: Planets; Bryn Hubbard, Editor-in-Chief, JGR: Earth Surface; Miguel Goni, Editor-in-Chief, JGR: Biogeosciences; Ellen Thomas, Editor-in-Chief, Paleoceanography; Philip Wilkinson, Editor-in-Chief, Radio Science; Mark Moldwin, Editor-in-Chief, Reviews of Geophysics; Delores J. Knipp, Editor-in-Chief, Space Weather; John Geissman, Editor-in-Chief, Tectonics; and Martyn Clark, Editor-in-Chief, Water Resources Research

Citation:

Hanson, B., J. Lunn, B. van der Pluijm, J. Orcutt, R. R. Colwell, S. Trumbore, T. W. Becker, N. Diffenbaugh, R. Pincus, M. Liemohn, U. ten Brink, P. Brewer, M. Zhang, S. A. Hauck II, B. Hubbard, M. Goni, E. Thomas, P. Wilkinson, M. Moldwin, D. J. Knipp, J. Geissman, and M. Clark (2017), Earth and space science for the benefit of humanity, Eos, 98, https://doi.org/10.1029/2018EO071991. Published on 20 April 2017.

Text © 2017. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Interglacials, including the present (Holocene) period, are warm, low land ice extent (high sea level), end-members of glacial cycles. A recent article from the Past Interglacials Working Group of PAGES in Reviews of Geophysics, Interglacials of the last 800,000 years,  identifies 11 interglacials, summarises the common features and differences between them, and highlights how particular interglacials can enlighten us about the climate system. They also describe the likely extent of the present interglacial both in the absence and presence of human influence on the climate system. AGU asked the authors of the article to highlight the important results that have emerged from their research and some of the important questions that remain.

Why is this topic timely? What recent advances in particular are leading to a new understanding or synthesis?

We live in an interglacial:  Interglacials represent the warm end of the conditions Earth has experienced in the 800,000 year period we considered.  Because of human actions, we expect that the world is going, by the end of the century, to be considerably warmer than it has been in the last few thousand years. While the interglacials don’t provide any perfect analogues for that, they do offer a range of examples, providing insights into the impacts of warmer than present conditions in certain regions of Earth.  Learning from them has become a practical possibility because huge progress has been made in the last few years in producing well-resolved quantitative datasets covering multiple interglacials in marine sediment cores, ice cores, and terrestrial sequences.  The ice core record provides crucial quantification of the climate forcing (from greenhouse gases in particular), while there are now sufficient records of sea surface temperatures that we can, at least semi-quantitatively, recognise the spatial pattern of warmth in each interglacial. Finally, it is only in the last few years that it has become possible to run various classes of climate models with boundary conditions representing a range of interglacial conditions.

Thus we now have a strong motivation to understand the properties of interglacials as a whole and individually and, crucially, the modeling tools and validating data that enable us to do so quantitatively.  On this basis, we felt it was timely to summarise what is known, both as a stimulus to further data collection and as a resource for deriving the principles and processes determining the diversity of interglacials.

What are the societal implications of this new synthesis or implications for understanding our current interglacial and anthropogenic warming?

Firstly it’s important to emphasise that there is no analogue for the anthropogenic warming we are currently experiencing.  In the 800,000 years we studied, the concentration of CO₂ never exceeded 300 ppm until the 20th century, while it recently climbed above 400 ppm and is still rising by 2–3 ppm per year.  However, while the causes of warmth have no analogue in our record, we do see times when parts of the world were warmer than today.

Our synthesis highlighted two periods of particular interest in this regard.  Marine isotope stage 11, around 400,000 years ago, was relatively warm and particularly long (of order 30,000 years); it therefore provides an opportunity to see what happens to sectors such as ice sheets and terrestrial ecosystems subjected to an extended period of warmth.  The last interglacial, running from about 130,000 to 115,000 years ago, seems to be the warmest in the last 800,000 years in many parts of the world.  In particular, both the Arctic and Antarctic appear to have experienced periods a few degrees warmer than present; the best evidence is that sea level was 6–9 m higher than present, so this suggests that such conditions, if they last for a few thousand years, take a significant bite out of one or both of the Greenland and Antarctic ice sheets.  The polar temperatures experienced in the last interglacial are well within the range of those predicted for 2100 under scenarios without strong mitigation of emissions, and that warmth is expected to persist unless CO₂ is actively removed from the atmosphere.  Thus the last interglacial acts as a rather solid data-based reminder that the commitment to sea level rise from continued warming could be very scary.

What are the major unsolved or unresolved questions, and where are additional data or modeling efforts needed?

Although we have documented the occurrence of interglacials, there is not yet a convincing account of why and when interglacials occur.  We know that it is linked to astronomical changes (in Earth’s orbit and axial tilt).  However, not every favourable set of astronomical conditions leads to an interglacial, and the process of interglacial onset is complex, apparently involving synergistic changes in greenhouse gas concentrations, ocean circulation, and ice sheets.  Understanding this requires, as always, more data: in particular improvements in the chronologies of different archives are needed if we are to reconstruct the sequence of events across the start of any interglacial before the present one.

While good progress has been made in assembling records of sea surface temperatures, there is still a paucity of long terrestrial records.  As a result, our knowledge of how continental climate changed and how terrestrial ecosystems responded in each interglacial remains sparse.  Constructing a good suite of such records is clearly a priority.

One other unresolved question I would highlight is that of the trend in CO₂ during interglacials.  In an influential series of papers, including a recent paper in Reviews of Geophysics, Bill Ruddiman has proposed that the slow increase in CO₂ that occurred during the last 8000 years was unusual, resulted from an early anthropogenic influence, and perhaps even staved off the end of our interglacial and the descent into a glacial period.  This is obviously an intriguing idea.  There are however other interglacial periods during which CO₂ increased naturally and no compelling argument as to what determines the trend in each interglacial.  Carbon cycle models can reproduce both increases and decreases under different assumptions.  We concluded that the extent to which human actions have influenced CO₂ concentrations over the last few millennia remains open; this needs to be resolved.

—Mark Moldwin, Editor in Chief, Reviews of Geophysics; email: mmoldwin@umich.edu

Citation:

Moldwin, M. (2016), Insights on climate systems from interglacials, Eos, 97, https://doi.org/10.1029/2018EO049553. Published on 08 April 2016.

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It is only in the last few decades that substantial research efforts have been focused on the interactions of river discharge with tidal waves and storm surges into regions beyond the limit of salinity intrusion. A recent article in Reviews of Geophysics, Tidal river dynamics: Implications for deltas, provides a description of state-of-the-art methods for a comprehensive analysis of water levels, wave propagation, discharges, and inundation extent in tidal rivers is provided. Implications for lowland river deltas are also discussed in terms of sedimentary deposits, channel bifurcation, avulsion, and salinity intrusion, addressing contemporary research challenges.  AGU asked the authors of the article to highlight the important results that have emerged from their research and some of the important questions that remain.

What is a tidal river?

A tidal river is the part of a river-estuary system where there are strong interactions between tides and river flow.  River processes increasingly dominate over tidal processes farther upstream. In large rivers like the Yangtze and Amazon, these interactions may extend many hundreds of kilometers upstream past the upstream limit of salinity intrusion. In the more seaward parts of a tidal river, the average tidal range and the seasonal variations in river stage are often about equal. Farther upstream, tidal range decreases during periods of high river flow, and seasonal river stage variations greatly exceed tidal amplitudes.  Defining boundaries for tidal rivers has proven complicated and controversial, in part because administrative definitions may not map well onto the actual dynamics. It seems logical that the tidal river should begin at the landward boundary of an estuary – but where is that? Estuaries have been defined by some scientists to extend only to the landward limit that saline water intrudes into the river. But this limit varies strongly, and the Amazon has no salinity intrusion at all, yet it certainly has an estuary. Others have suggested that an estuary extends upstream to the tidal limit. This can be 500 to almost 1000 km from the ocean in some large rivers; such a definition is counterintuitive. We thus defined the seaward boundary of the tidal river to occur at the point where monthly variations in stage exceed monthly variations in tidal range. In the tidal river upstream of this point, the lowest tidal water levels will occur during neap tides  not spring tides, as would be the case near the ocean. Usually, this boundary is seasonally stable; whereas a definition based on the salinity intrusion limit is not. In both definitions, the landward tidal-river boundary coincides with the reasonably stable upstream limit of tidal intrusion.

Why is this topic timely and important?

Tidal rivers are hotspots of climate change impact. They are affected both by changing river discharge regimes and by rising sea levels. Knowledge about the processes governing tidal river dynamics has implications for the way climate change impacts are perceived. For example, sea level rise may not directly translate into a rise of extreme water levels because of corresponding changes in the dynamics of the tidal river. In channels across the freshwater part of the Rhine-Meuse delta, for example, mean water levels have increased at the same pace as the mean sea level, but both the high and the low extremes have dropped. The reduction of the lowermost water levels in summer now causes enhanced salinity intrusion, jeopardizing freshwater availability in southwestern parts of The Netherlands. Over the length of a tidal river, water levels govern the inundation frequency of the adjacent wetlands. Ecosystems may have a capacity to adapt to a changing inundation regime, but in the near future, this adaptation capacity will be put to the test by discharge regime changes in response to climate change, and human mitigation measures. The importance of tidal river dynamics is further manifest in delta geology and management. In natural deltas without engineered dikes, tidal motions often largely control the chance of a levee breach, and cause rhythmic patterns of sediment deposition. In human controlled systems such as the Mississippi Delta, river-flows may control flood frequency, but it is questionable whether tidal effects can be ignored when developing flood control measures.

What recent advances in particular are leading to a new understanding or synthesis?

The study of tidal river dynamics unites two disciplines, hydrology and physical oceanography, in ways that are perhaps unexpected in either field. Hydrologists have long ignored the tides. In studies of estuaries, physical oceanographers often consider river discharge as either constant or absent, and tides as stationary. Improved methods of time-series analysis and multiscale numerical modeling facilitate studies of tidal rivers that combine the two worlds. A major challenge in tidal river water level dynamics is to identify how individual tidal waves, which can readily be predicted in coastal waters, develop as they propagate upstream in a shallow river and interact with the discharge, and with tides of other frequencies. The harmonic analysis method, generally used for water level prediction in harbors, assumes that the tidal motion is statistically stationary, an assumption that is invalid in a tidal river. Wavelet analysis is appropriate for nonstationary data series, but has low frequency resolution. Recent techniques have improved harmonic analysis, to address nonstationary processes. Results have shown, for example, that a simple relation often exists between river discharge and the ratio of amplitudes in a tidal river and at the coast. Flexible mesh numerical flow models have further contributed to improved understanding of the land-sea continuum. Contemporary model simulation environments allow a holistic, integrated approach, where the effects of the tidal motion and sea-level variation can be studied in a tidal river and its adjacent wetlands.

What are the implications for society (e.g., cities, coastal engineering, flood control, water supply, shipping, fisheries, and recreation) of this new synthesis and understanding of tidal rivers.  That is, can you provide some brief examples of their importance and how the new understandings help?

Recent understandings support the need to abandon the use of harmonic analysis for prediction of river tides, for example by harbour authorities. Models and new tools for analysis of tidal river dynamics can be used to better predict water levels, an objective that is directly relevant to navigation, water supply, habitat restoration, and fisheries management. Simple models are now available that can be used to explore how engineering activity, such as channel deepening by dredging, may affect the highest and lowest water levels in a tidal river. Higher river discharges attenuate the tide, so that an increased discharge does not necessarily result in an increased flood risk in the lower reaches of a tidal river. In the landward reaches of a tidal river, high river discharges damp tidal motions, such that changes in discharge have a more direct consequence for water level dynamics, and possible flooding. Understanding tidal rivers is also key to controlling salinity intrusion, relevant for drinking water supply and agriculture. In particular, tidal rivers modulate river discharge, introducing fortnightly variations that are predictable, and thus can be anticipated. It is likely that new understanding of tidal river dynamics and novel time-series analysis methods can be used to develop simple tools to predict salinity intrusion length. In a similar vein, the latest insights and tools can support river restoration efforts, offering support to the management of water level regimes, which are linked to ecosystem zonation.

What are the major unsolved or unresolved questions, and where are additional data or modeling efforts needed?

The complexity of tides in freshwater environments increases in branching channels networks. Potentially, the tidal motion can become chaotic. More research is needed to explore tidal propagation, sediment transport, and geomorphology in such systems. Much can also be learned from the interpretation of existing long-term water level records. Records for many river harbors extend at least a century, providing a wealth of information. In conjunction with hindcasts of the river discharge and ocean tidal amplitudes, historical analyses of harbor tides can reveal natural and anthropogenic trends in tidal river dynamics, and possible regime changes. There is also a lack of knowledge about the subaqueous geomorphology of tidal rivers, which cause spatial and temporal variations in the degree in which the bed resists the flow. In particular, the development of dunes in tidal rivers where the sediment characteristics transition from sand to mud needs to be better understood. New techniques for in situ monitoring can assist further exploration of the associated processes governing flow and sediment transport. Finally, there is a gap in knowledge of the interactions between tidal river hydrodynamics and wetland vegetation. Holistic modelling efforts are needed to better identify the tolerance of wetland species to shifts in water level regimes.

—Mark Moldwin, Editor in Chief, Reviews of Geophysics, email: mmoldwin@umich.edu

Citation:

Moldwin, M. (2016), Tidal river dynamics, Eos, 97, https://doi.org/10.1029/2018EO049541. Published on 06 April 2016.

Text © 2016. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.