From Yale University: “What hurricanes and space storms have in common”

From Yale University

10.26.22
Jim Shelton

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Fred Mamoun
fred.mamoun@yale.edu
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Image created by G. Laughlin and K. Gerbig using OpenAI’s DALL•E

Those massive, swirling radar images shown on TV during hurricane season may have an unexpected analog in the deepest reaches of the cosmos — extrasolar storms of dust and gas from which nascent planets begin to form.

Both storms — terrestrial and extrasolar — feature churning whirlpools of vapor. Both use latent heat to sustain their prodigious circulating motion in the face of energy-draining dissipation.

But while the Atlantic hurricane season lasts four months a year and is restricted to a portion of planet Earth, space storms may play out over millions of years and occur in protoplanetary disks throughout the universe.

Konstantin Gerbig, a graduate student in the Department of Astronomy, and Gregory Laughlin, a professor of astronomy in Yale’s Faculty of Arts and Sciences, have documented a mechanism that can power these space storms and noted the way they mirror terrestrial hurricanes [The Astrophysical Journal (below)].

As forecasters continue to monitor this year’s Atlantic hurricane season, Yale News spoke with Gerbig and Laughlin about their findings — and what insight they might provide about hurricane-like storms near and far.

When did the connection between terrestrial and extrasolar storms first occur to you?

Gregory Laughlin: Prior to moving to the East Coast from California, tropical storms and hurricanes were something of a far-away concern for me. But there’s a certain immediacy to seeing a “Tropical Storm Warning” on one’s cell phone, which prompted me to realize that I didn’t really understand the physics of hurricanes. That got me reading the literature, especially the articles by Kerry Emanuel at MIT. I came to appreciate the importance of the latent heat of water in driving the process and realized that very analogous conditions might exist in the planet-forming disks of gas and dust orbiting young stars.

What do the mechanisms that drive these storms have in common?

Konstantin Gerbig: The extraterrestrial storms we envisioned are reliant on a mechanism that is very similar to the one that drives hurricanes on Earth.

Hurricanes are reliant on the warm ocean water in the tropics. The strong winds roil the water surface and, in the process, saturate the air in the hurricane with water, leading to cloud formation and heavy rain. The release of latent heat in the eye of the hurricane drives vigorous upwards convection which in turn leads to faster wind speeds. This ‘engine’ is shut off when the hurricane is deprived of its water supply by hitting land.

While protoplanetary disks do not have an ocean or liquid water in general, they are rich in dust grains that are encased in a water-ice coating. Much like hurricanes on Earth, we proposed that winds in the protoplanetary disks can intensify significantly if they can access the energy hidden in the solid phase of water ice. As such, the energy source for extrasolar hurricanes is the same as for hurricanes on Earth. Another similarity is that both mechanisms are dependent on the mixing efficiency between the gaseous winds and the water, and as a result the storm in the disk would also cease to exist if the dust grains are removed.

Was it difficult to show that whirlpools in space can be sustained long enough in a protoplanetary disk to create such a storm?

Gerbig: In order to show that these extraterrestrial storms are indeed feasible, we focused on two questions: Do protoplanetary disks offer favorable conditions for the proposed mechanism to operate in the first place? Second, is the engine strong enough to compensate for the loss of energy it is subjected to by nature of being embedded in a viscous protoplanetary disk?

To answer these questions, we would ideally look at real observations of protoplanetary disks. However, while observations of such disks have gotten better and better in recent years, the resolution of our telescopes remains far below what would be required to see storms of the sizes that we predict for proposed hurricanes. Because of this, we performed computer simulations to test the feasibility of our storms.

The plan was to figure out what initial conditions are required to produce a storm that can fight against a given viscosity, which is a measure for the disk’s internal friction. This way, we were able to constrain the ideal location for such storms to operate to just outside the so-called water-snow line — a key location in protoplanetary disks marking the boundary between water vapor and water ice. One challenge in interpreting our simulations is the disk viscosity, which is considered an unknown and consequently hotly debated property of protoplanetary disks. We found that our mechanism works best for protoplanetary disks that are of relatively low viscosity.

Is there a visual similarity between hurricanes and storms in space?

Gerbig: We envision the hurricane analogue in protoplanetary disks to appear quite similar in flow structure to terrestrial hurricanes. Both are rotating storms centered around an ‘eye’ region in which convection operates. We also predict the extraterrestrial storm to be enhanced in water content, much like how hurricanes have easily recognizable cloud patterns.

There are also some interesting differences. For example, we expect the extraterrestrial hurricane to be an anticyclone (rotating in the opposite direction of a terrestrial hurricane). This is because the protoplanetary disk possesses an inherent rotation that differs from the rotation of a planet, such that only anticyclonic storms can be in geostrophic balance. Also, since the gravity in the protoplanetary disk pulls towards the disk midplane, there are two ‘upward’ directions in the disks, which leads to two storms, one above and the other below the midplane.

How can this information be used to further research?

Gerbig: Our proposed mechanism [see the science paper] would be important for understanding planet formation as the extra-terrestrial hurricane would capture dust particles much like how the terrestrial hurricane can trap a flock of birds. If the vortex is long-lived enough, and continuously supplied with new dust and pebbles, it can serve as a site for dust coagulation and the formation of planetary embryos. This is a very exciting result as it would be another pointer to the water-snow line as a location of crucial importance in protoplanetary disks.

Science paper:
The Astrophysical Journal
See the science paper for detailed material with images.

See the full article here .

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Yale University is a private Ivy League research university in New Haven, Connecticut. Founded in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and one of the nine Colonial Colleges chartered before the American Revolution. The Collegiate School was renamed Yale College in 1718 to honor the school’s largest private benefactor for the first century of its existence, Elihu Yale. Yale University is consistently ranked as one of the top universities and is considered one of the most prestigious in the nation.

Chartered by Connecticut Colony, the Collegiate School was established in 1701 by clergy to educate Congregational ministers before moving to New Haven in 1716. Originally restricted to theology and sacred languages, the curriculum began to incorporate humanities and sciences by the time of the American Revolution. In the 19th century, the college expanded into graduate and professional instruction, awarding the first PhD in the United States in 1861 and organizing as a university in 1887. Yale’s faculty and student populations grew after 1890 with rapid expansion of the physical campus and scientific research.

Yale is organized into fourteen constituent schools: the original undergraduate college, the Yale Graduate School of Arts and Sciences and twelve professional schools. While the university is governed by the Yale Corporation, each school’s faculty oversees its curriculum and degree programs. In addition to a central campus in downtown New Haven, the university owns athletic facilities in western New Haven, a campus in West Haven, Connecticut, and forests and nature preserves throughout New England. As of June 2020, the university’s endowment was valued at $31.1 billion, the second largest of any educational institution. The Yale University Library, serving all constituent schools, holds more than 15 million volumes and is the third-largest academic library in the United States. Students compete in intercollegiate sports as the Yale Bulldogs in the NCAA Division I – Ivy League.

As of October 2020, 65 Nobel laureates, five Fields Medalists, four Abel Prize laureates, and three Turing award winners have been affiliated with Yale University. In addition, Yale has graduated many notable alumni, including five U.S. Presidents, 19 U.S. Supreme Court Justices, 31 living billionaires, and many heads of state. Hundreds of members of Congress and many U.S. diplomats, 78 MacArthur Fellows, 252 Rhodes Scholars, 123 Marshall Scholars, and nine Mitchell Scholars have been affiliated with the university.

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Yale is a member of the Association of American Universities (AAU) and is classified among “R1: Doctoral Universities – Very high research activity”. According to the National Science Foundation , Yale spent $990 million on research and development in 2018, ranking it 15th in the nation.

Yale’s faculty include 61 members of the National Academy of Sciences , 7 members of the National Academy of Engineering and 49 members of the American Academy of Arts and Sciences . The college is, after normalization for institution size, the tenth-largest baccalaureate source of doctoral degree recipients in the United States, and the largest such source within the Ivy League.

Yale’s English and Comparative Literature departments were part of the New Criticism movement. Of the New Critics, Robert Penn Warren, W.K. Wimsatt, and Cleanth Brooks were all Yale faculty. Later, the Yale Comparative literature department became a center of American deconstruction. Jacques Derrida, the father of deconstruction, taught at the Department of Comparative Literature from the late seventies to mid-1980s. Several other Yale faculty members were also associated with deconstruction, forming the so-called “Yale School”. These included Paul de Man who taught in the Departments of Comparative Literature and French, J. Hillis Miller, Geoffrey Hartman (both taught in the Departments of English and Comparative Literature), and Harold Bloom (English), whose theoretical position was always somewhat specific, and who ultimately took a very different path from the rest of this group. Yale’s history department has also originated important intellectual trends. Historians C. Vann Woodward and David Brion Davis are credited with beginning in the 1960s and 1970s an important stream of southern historians; likewise, David Montgomery, a labor historian, advised many of the current generation of labor historians in the country. Yale’s Music School and Department fostered the growth of Music Theory in the latter half of the 20th century. The Journal of Music Theory was founded there in 1957; Allen Forte and David Lewin were influential teachers and scholars.

In addition to eminent faculty members, Yale research relies heavily on the presence of roughly 1200 Postdocs from various national and international origin working in the multiple laboratories in the sciences, social sciences, humanities, and professional schools of the university. The university progressively recognized this working force with the recent creation of the Office for Postdoctoral Affairs and the Yale Postdoctoral Association.

Notable alumni

Over its history, Yale has produced many distinguished alumni in a variety of fields, ranging from the public to private sector. According to 2020 data, around 71% of undergraduates join the workforce, while the next largest majority of 16.6% go on to attend graduate or professional schools. Yale graduates have been recipients of 252 Rhodes Scholarships, 123 Marshall Scholarships, 67 Truman Scholarships, 21 Churchill Scholarships, and 9 Mitchell Scholarships. The university is also the second largest producer of Fulbright Scholars, with a total of 1,199 in its history and has produced 89 MacArthur Fellows. The U.S. Department of State Bureau of Educational and Cultural Affairs ranked Yale fifth among research institutions producing the most 2020–2021 Fulbright Scholars. Additionally, 31 living billionaires are Yale alumni.

At Yale, one of the most popular undergraduate majors among Juniors and Seniors is political science, with many students going on to serve careers in government and politics. Former presidents who attended Yale for undergrad include William Howard Taft, George H. W. Bush, and George W. Bush while former presidents Gerald Ford and Bill Clinton attended Yale Law School. Former vice-president and influential antebellum era politician John C. Calhoun also graduated from Yale. Former world leaders include Italian prime minister Mario Monti, Turkish prime minister Tansu Çiller, Mexican president Ernesto Zedillo, German president Karl Carstens, Philippine president José Paciano Laurel, Latvian president Valdis Zatlers, Taiwanese premier Jiang Yi-huah, and Malawian president Peter Mutharika, among others. Prominent royals who graduated are Crown Princess Victoria of Sweden, and Olympia Bonaparte, Princess Napoléon.

Yale alumni have had considerable presence in U.S. government in all three branches. On the U.S. Supreme Court, 19 justices have been Yale alumni, including current Associate Justices Sonia Sotomayor, Samuel Alito, Clarence Thomas, and Brett Kavanaugh. Numerous Yale alumni have been U.S. Senators, including current Senators Michael Bennet, Richard Blumenthal, Cory Booker, Sherrod Brown, Chris Coons, Amy Klobuchar, Ben Sasse, and Sheldon Whitehouse. Current and former cabinet members include Secretaries of State John Kerry, Hillary Clinton, Cyrus Vance, and Dean Acheson; U.S. Secretaries of the Treasury Oliver Wolcott, Robert Rubin, Nicholas F. Brady, Steven Mnuchin, and Janet Yellen; U.S. Attorneys General Nicholas Katzenbach, John Ashcroft, and Edward H. Levi; and many others. Peace Corps founder and American diplomat Sargent Shriver and public official and urban planner Robert Moses are Yale alumni.

Yale has produced numerous award-winning authors and influential writers, like Nobel Prize in Literature laureate Sinclair Lewis and Pulitzer Prize winners Stephen Vincent Benét, Thornton Wilder, Doug Wright, and David McCullough. Academy Award winning actors, actresses, and directors include Jodie Foster, Paul Newman, Meryl Streep, Elia Kazan, George Roy Hill, Lupita Nyong’o, Oliver Stone, and Frances McDormand. Alumni from Yale have also made notable contributions to both music and the arts. Leading American composer from the 20th century Charles Ives, Broadway composer Cole Porter, Grammy award winner David Lang, and award-winning jazz pianist and composer Vijay Iyer all hail from Yale. Hugo Boss Prize winner Matthew Barney, famed American sculptor Richard Serra, President Barack Obama presidential portrait painter Kehinde Wiley, MacArthur Fellow and contemporary artist Sarah Sze, Pulitzer Prize winning cartoonist Garry Trudeau, and National Medal of Arts photorealist painter Chuck Close all graduated from Yale. Additional alumni include architect and Presidential Medal of Freedom winner Maya Lin, Pritzker Prize winner Norman Foster, and Gateway Arch designer Eero Saarinen. Journalists and pundits include Dick Cavett, Chris Cuomo, Anderson Cooper, William F. Buckley, Jr., and Fareed Zakaria.

In business, Yale has had numerous alumni and former students go on to become founders of influential business, like William Boeing (Boeing, United Airlines), Briton Hadden and Henry Luce (Time Magazine), Stephen A. Schwarzman (Blackstone Group), Frederick W. Smith (FedEx), Juan Trippe (Pan Am), Harold Stanley (Morgan Stanley), Bing Gordon (Electronic Arts), and Ben Silbermann (Pinterest). Other business people from Yale include former chairman and CEO of Sears Holdings Edward Lampert, former Time Warner president Jeffrey Bewkes, former PepsiCo chairperson and CEO Indra Nooyi, sports agent Donald Dell, and investor/philanthropist Sir John Templeton,

Yale alumni distinguished in academia include literary critic and historian Henry Louis Gates, economists Irving Fischer, Mahbub ul Haq, and Nobel Prize laureate Paul Krugman; Nobel Prize in Physics laureates Ernest Lawrence and Murray Gell-Mann; Fields Medalist John G. Thompson; Human Genome Project leader and National Institutes of Health director Francis S. Collins; brain surgery pioneer Harvey Cushing; pioneering computer scientist Grace Hopper; influential mathematician and chemist Josiah Willard Gibbs; National Women’s Hall of Fame inductee and biochemist Florence B. Seibert; Turing Award recipient Ron Rivest; inventors Samuel F.B. Morse and Eli Whitney; Nobel Prize in Chemistry laureate John B. Goodenough; lexicographer Noah Webster; and theologians Jonathan Edwards and Reinhold Niebuhr.

In the sporting arena, Yale alumni include baseball players Ron Darling and Craig Breslow and baseball executives Theo Epstein and George Weiss; football players Calvin Hill, Gary Fenick, Amos Alonzo Stagg, and “the Father of American Football” Walter Camp; ice hockey players Chris Higgins and Olympian Helen Resor; Olympic figure skaters Sarah Hughes and Nathan Chen; nine-time U.S. Squash men’s champion Julian Illingworth; Olympic swimmer Don Schollander; Olympic rowers Josh West and Rusty Wailes; Olympic sailor Stuart McNay; Olympic runner Frank Shorter; and others.