Willem Van Rensselaer Malkus

Willem Van Rensselaer Malkus died in Falmouth, Massachusetts, on Saturday May 28, at the age of 92. He was born in Brooklyn, New York, on November 19, 1923. He studied at the University of Michigan and Cornell University, and after serving three years in the Navy, received a PhD in physics from the University of Chicago in 1950. He was a research associate and physical oceanographer at the Woods Hole Oceanographic Institution until 1958, held a joint professorial appointment with MIT until 1960, was a professor at UCLA until 1969, and was a professor of applied mathematics at MIT until retirement in 1996.

Malkus’s first studies concerned natural phenomena: He searched for magnetic monopoles in space in his PhD thesis under Edward Teller and Herbert Anderson (although he frequently emphasized being particularly inspired by Enrico Fermi as a graduate student). At Woods Hole, he constructed the first devices to measure the electric potential generated by ocean currents in Earth’s magnetic field. Thereafter, he became known for inventing creative approaches to fundamental problems in fluid mechanics, mostly generated by laboratory experiments. Many areas initiated by Malkus’s experiments and theories have developed significant branches of study. He persistently stimulated colleagues and students to develop original contributions, and his generous and enthusiastic delight while describing their triumphs was central to his personality.

Malkus made fundamental contributions to the theory of thermal convection, turbulence, magnetohydrodynamics, precession-driven flows and elliptical flows, and their applications in geophysics. He was particularly focused on the magnetic dynamo problem and was the first to construct a laboratory dynamo experiment in which magnetic fields are generated by motions in an electrically conducting fluid. While this first experiment failed in producing the dynamo effect, more recent efforts have succeeded in demonstrating this process that is responsible for the generation of the earth’s magnetic field and that of other planets and stars. In 1968, he proposed a novel theory for a precession driven geodynamo well known to workers in the field.

Malkus delighted in variational principles and was always seeking new applications for them, especially in deducing criteria for hydrodynamic stability. Motivated by his early experiments on thermal convection, Malkus suggested that in turbulent convection the heat transport tends to be maximized subject to certain constraints. This proposal stimulated Louis Howard and Fritz Busse to develop the mathematical theory of upper bounds on the heat transport by turbulent convection. He also teamed up with Louis Howard to devise the chaotic waterwheel, a device now widely used in the teaching of chaos theory since it is governed by the famous set of 3 equations derived by Edward Lorenz which display chaos. Malkus often joked that Lorenz’s equations much better described his mechanical toy than the phenomenon they were intended to describe - atmospheric convection.

Malkus and George Veronis formed the Geophysical Fluid Dynamics (GFD) Summer Program at Woods Hole Oceanographic Institution in 1959. They designed its unique structure and ran it for many years. This program continues to flourish and has produced an entire community of scholars, with many student alumni now leaders in their fields. In 2008, the GFD program’s founding members were awarded the Excellence in Geophysical Education Award by the American Geophysical Union.

He was a fellow of the American Academy of Arts and Sciences, the American Physical Society, the American Geophysical Union, and the John Simon Guggenheim Foundation. In 1972, he was elected a Member of the National Academy of Sciences.