Philip Drazin, a leading international expert in fluid mechanics, died of cancer at his home in Bristol, England, on 10 January 2002.
Philip, born on 25 May 1934, was sent from wartime London to board at St. Christopher’s School, Letchworth. In 1955, he gained first-class honors in the Mathematical Tripos at the University of Cambridge. He stayed on at Cambridge to pursue his PhD, which he received in 1958, with George Batchelor and G. I. Taylor as his PhD supervisors. There, Philip began what was to become seminal work on hydrodynamic stability and on shear flows. He then spent two years at MIT as a research associate with Jule Charney in meteorology before moving to the University of Bristol in 1960, where he eventually advanced to become a professor of applied mathematics in 1981.
Philip’s research, for example his applications in meteorology with results on the stability of stratified shear flow and mountain waves, the instability of gravity waves, and the vertical propagation of internal waves, has influenced many areas of applied mathematics. In 1961, the Journal of Geophysical Research published a paper he coauthored with Charney on the seasonal dependence of the vertical structure of the stratosphere. That paper, which became a citation classic, helped to initiate an explosion in theoretical and observational work in the stratosphere that occurred in subsequent decades. Philip’s studies of waves and stable stratified flow around mountains have been widely used in the development of numerical models for weather forecasting and for predicting the dispersion of environmental pollution. The Drazin layer description of stratified flow near the top of a mountain will remain his memorial like a cairn of stones. His later work extended to nonlinear analysis, studies of chaotic advection, and the analytic approximation of functions. Philip was extremely active in research right up until his death, and collaborated with colleagues in many universities worldwide.
Philip was a communicator of mathematics. His influential book Hydrodynamic Stability (Cambridge U. Press, 1981) with W. H. Reid has no competitor. In the last years of his life, Philip wrote a book that serves as an introduction to this work, and just before he died, was proud that it had been completed and sent to the publishers. His other textbooks, Solitons (Cambridge U. Press, 1983), Solitons: An Introduction (Cambridge U. Press, 1989) with R. S. Johnson, and Nonlinear Systems (Cambridge U. Press, 1992), were based on courses given at Bristol and have also been successful. Philip served on the editorial board of four periodicals and assisted the UK’s Institute of Mathematics and Its Applications with its publication of Mathematics Today.
A dedicated university teacher, he taught a full load of lectures in an inspiring and masterful manner, was a founder and director of the Bristol MSc Course in Fluid Mechanics, and helped set up the University of Bath MSc in Modern Applications of Mathematics. Philip supervised numerous graduate students and took great care to look after and guide the careers of new staff and faculty members. To his students, he carefully emphasized the links between applied mathematics and physical reality. In the 19 years he led the applied mathematics and numerical analysis group at Bristol, Philip laid the foundations for, and contributed greatly to, the group’s present high international profile.
After his retirement from Bristol in 1999, he continued active research work at both Bristol and Bath and gave lecture courses at Bath and Oxford University. It is fitting that, in the year of his retirement, he received the Symons Memorial Medal, the premier award of the Royal Meteorological Society.
It is characteristic of Philip’s care with the English language and his love of quotations and of the history of mathematics that he served for many years as the mathematical consultant to the Oxford English Dictionary. Philip was the driving force behind a Royal Meteorological Society committee that published the collected papers of Lewis Fry Richardson. He showed his empathy with Richardson’s extraordinarily original ideas about meteorology, mathematics, and the modeling of conflict. He was a superb editor and wrote in the introduction a most insightful piece on Richardson’s work on fractals.
We remember Philip as a genuine scholar with a brilliant mind and unassuming personality. Although rarely interested in university politics, he was skillful enough to participate fully in university activities without wasting time on bureaucracy that would impede his research activity. Although he cooperated in every way with the performance measures to which universities are subject, he rose above and saw beyond them: Concerned to find the origins and truth in every topic that he studied, he constantly reminded all of us that it was the quality of papers that mattered, not the quantity or any other artificial measure. Philip will live long in our hearts, both as a colleague and a friend who enhanced both mathematics and our lives.
