Portal de Periódicos da CAPES

Douglas Orson ReVelle (1945–2010)

2010; Wiley; Volume: 45; Issue: 5 Linguagem: Inglês

10.1111/j.1945-5100.2010.01089.x

1945-5100

Peter Brown,

Ionosphere and magnetosphere dynamics

Douglas O. ReVelle died unexpectedly on May 2, 2010, following a brief illness. Doug was born in Rochester, NY, the youngest of three boys, all of whom pursued careers in the sciences. Doug was a leading meteor scientist with long-standing interests in many theoretical problems related to meteor entry, acoustic production from bright fireballs, and the flux of meteoroids at the Earth. He was trained as an atmospheric scientist at the University of Michigan in the late 1960s and early 1970s. His early research interest focused on problems of meteor entry and particularly shock processes in the atmosphere created by the hypersonic passage of meteoroids. This dual interest in how the atmosphere affected meteoroids and vice-versa was the defining theme in his future research where he effectively bridged the disparate areas of meteor science and infrasound studies. His 1976 paper “On meteor-generated infrasound” laid the modern foundations for interpretation and analysis of infrasound from meteors. He also recognized, together with Gene Shoemaker, that airwave recordings made by the U.S. military of large fireballs could be used to directly estimate the influx of meter-sized bodies to the Earth. This was a project he revisited many times over a period of some 30 years, most recently publishing a final estimate based on these data only a few years before his death. Doug’s early research career was as a post doctoral fellow at the Herzberg Institute of Astrophysics in Ottawa working with Peter Millman and Bruce McIntosh, and later at the Carnegie Institution in Washington with George Wetherill. His research at this time focused on interpretation of meteoroid entry, fireball observations, and bolide kinematics. Together with Wetherill, he examined the Prairie network fireball data and identified those events most plausibly producing meteorites on the ground. This work served as the backdrop to his ongoing theoretical model comparisons among the three known meteorite- producing fireballs (Príbřam, Lost City, and Innisfree). A major goal of this work was to reconcile the disparate estimates of photometric and single-body dynamic masses from fireball data. His work in this area continued until quite recently, culminating in publication in 2005, together with Zdenek Ceplecha, of a comprehensive model of bolide ablation, explicitly accounting for the role of fragmentation and establishing a new, modern scale for fireball luminous efficiency. This new model resolved this long-standing difference between photometric and dynamic mass scales in fireball data, identifying fragmentation as the underlying cause. It also provided the framework for a new level of understanding of how objects fragment in the atmosphere and, by extension, the physical properties of larger meteoroids. His later research was performed as a technical staff member at the Los Alamos National Laboratory and focused more on infrasound monitoring than bolide research. During his tenure at Los Alamos he was able to develop a new acoustic-gravity wave model of shock production from bolides and further extend his numerical entry modeling work to very large fireballs, and apply this work to very large fireballs observed by U.S. government satellite systems. Doug retired from Los Alamos in February, 2010, but he continued active research until just before his death. His irrepressible love of all aspects of meteor research and his energy for the field he so cherished was apparent to all those who were fortunate enough to work with him over the years. He will be deeply missed by his many colleagues and friends around the world.