RADAR IN IN METEOROLOGY: BATTAN MEMORIAL AND

40TH ANNIVERSARY

RADAR METEOROLOGY CONFERENCE

EDITED BY

DAVID ATLAS

American Meteorological Society Boston 1990 © American Meteorological Society 1990 Originally published by American Meteorological Society Boston in 1990 Softcover reprint of the hardcover 1st edition 1990 Permission to use figures, tables, and brief excerpts from this publication in scientific and educational works is hereby granted, provided the source is acknowledged. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. ISBN 978-0-933876-86-6 ISBN 978-1-935704-15-7 (eBook) DOI 10.1007/978-1-935704-15-7 Typeset and printed in the of America by Lancaster Press, Lancaster, Pennsylvania. Section openers designed by Helga Hardy. Published by the American Meteorological Society, 45 Beacon Street, Boston, MA 02176. Richard E. Hallgren, Executive Director Kenneth C. Spengler, Executive Director Emeritus Evelyn Mazur, Assistant Executive Director Arlyn S. Powell, Jr., Publications Manager Editorial support provided by Laura Westlund, Pamela Jones, Jon Feld, Linda Esche, Brenda Gray, Harold Nagel, and Susan McClung. Table of Contents

Preface ...... 1x Acknowledgments ...... x1

Tribute to Professor Louis J. Battan Xlll

I. HISTORY 1 Early Developments of Radar during World War II . . . . . 3 ].0. Fletcher 2 in the United States Army's Laboratories ...... 7 Donald M. Swingle 3 Radar Meteorology at Radiation Laboratory, MIT, 1941 to 1947 ...... 16 Isadore Katz and Patrick f. Harney 4 Weather Radar at MIT ...... 22 Pauline M. Austin and Spiros G. Geotis 5 A History of Weather Radar Research in the U.S. Air Force . . . . . 32 James I. Metcalf and Kenneth M. Glover 6 Radar Meteorology at the National Severe Storms Laboratory, 1964-1986 ...... 44 7 A Meteorology in the · ...... 54 J.R. Probert-fones 8 The Stormy Weather Group () ...... 61 R.H. Douglas 9 History of Radar Meteorology in ...... 69 Nobuhiko Kodaira and ]ira Aoyagi 10 Radar Meteorology in India: A Brief Historical Perspective . . . . . 77 S.M. Kulshrestha 11 Radar Meteorology in The People's Republic of China ...... 80 Yu-Mao Xu 12 Early Foundations of the Measurement of Rainfall by Radar 86 and Carlton W. Ulbrich

v 13 Advances in Precipitation Physics Following the Advent of 'Weather Radar ...... 98 A.S. Dennis and W.F. Hitschfeld 14 Diversity in Radar Meteorology: Early Developments ...... 109 Thomas A. Seliga, Robert G. Humphries, and fames I. Metcalf 15 Foundations of Severe Storm Detection by Radar ...... 115 Ralph f. Donaldson 16 The Early Years of in Meteorology ...... 122 R.R. Rogers 17 The History of Radar Studies of the Clear Atmosphere ...... 130 Kenneth R. Hardy and Kenneth S. Gage 18 Investigation with Radar ...... 143 Earle R. Williams, Vladislav Mazur, and Spiros G. Geotis

II. SCIENCE AND TECHNOLOGY 19a Technology of Polarization Diversity for Meteorology 153 V.N. Bringi and A. Hendry 19b Technology of Polarization Diversity Radars for Meteorology: Panel Report ...... 191 fames I. Metcalf 20a Signal Processing for Atmospheric Radars ...... 199 R. Jeffrey Keeler and Richard E. Passarelli 20b Signal Processing: Panel Report ...... 230 · Dusan S. Zrnic 21a UHF JVHF Radar Techniques for Atmospheric Research and Wind Profiler Applications ...... 235 f. Ro"ttger and M.F. Larsen 21b Clear-Air Radar Technology: Panel Report ...... 282 Ben B. Balsley 22a Meteorological Radar Observations from Mobile Platforms . . . . 28 7 Peter H. Hildebrand and Richard K. Moore 22b AirbornejSpaceborne Radar: Panel Report ...... 315 David P. Jorgensen and Robert Meneghini 23a Cloud Microphysics and Radar ...... 323 A.R. Jameson and D.B. Johnson

vi 23b Cloud Microphysics and Radar: Panel Report ...... 341 Kenneth V. Beard and Robert M. Rauber 24a Convective Dynamics ...... 348 Peter Ray 24b Convective Dynamics: Panel Report ...... 391 R. Carbone, B. Foote, M. Moncrieff, T. Gal-Chen, W. Cotton, · M. Hjelmfelt, F. Roux, G. Heymsfield, and E. Brandes 25a Radar Observations of Tropical Weather Systems ...... 401 Frank D. Marks, Jr. 25b Tropical Meteorology: Panel Report ...... 426 Edward Zipser, Alan Betts, Frank Ruggiero, and Barry Hinton 26a Organization and Internal Structure of Synoptic and Mesoscale Precipitation Systems in Midlatitudes ...... 433 K.A. Browning 26b Mesoscale Organization and Processes: Panel Report ...... 461 David B. Parsons, Bradley F. Smull, and Douglas K. Lilly Appendix: Notes on the Physical Mechanisms of Mesoscale Precipitation Bands, Kerry A. Emanuel 27a Radar Research on the Atmospheric Boundary Layer ...... 477 Earl E. Gossard 27b The Atmospheric Boundary Layer: Panel Report ...... 528 Robert A. Kropfli 28a Radar Observations of the Free Atmosphere: Structure and Dynamics ...... 534 Kenneth S. Gage 28b Radar Observations of the Free Atmosphere: Panel Report 566 W.H. Hooke III. OPERATIONAL APPLICATIONS 29a Precipitation Measurement and Hydrology ...... 5 77 Jiirg Joss and Albert Waldvogel - Appendix A: Radar Data Processing and Short-Period Forecasting in the United Kingdom, C.G. Collier 29b Precipitation Measurement and Hydrology: Panel Report . . . . . 607 Paul L. Smith 30a Severe Detection by Radar 619 Donald W. Burgess and Leslie R. Lemon

vii 30b Severe Storm Detection: Panel Report ...... 648 Joseph H. Golden 31a The Application of Weather Radar to Aviation Meteorology . . . 65 7 T. Theodore Fujita and John McCarthy 31b Aviation Meteorology: Panel Report ...... 682 James Wilson References ...... 689 Current Addresses of Contributors ...... 777 Index ...... 781

viii Preface

This volume, dedicated to the memory of Professor Louis topics such as nowcasting, severe storm detection, and J. Battan, had its origin in the 40th Anniversary Radar hazards to aviation such as low-level wind shear. Radar Meteorology Conference, which took place in Boston on has led the way in of the atmosphere and 9-13 November 1987. The conference commemorated the its applications span virtually the entire discipline. More• anniversary of the first radar conference held at the Mas• over, its use continues to expand as the dream of putting sachusetts Institute of Technology on 14 March 1947. A weather radar in space approaches reality. At the same tribute to Professor Battan follows this preface. time, the impressive technological advances in this and After four and a half decades from the beginning of related fields provide further assurance that exciting pro• radar in World War II, those of us nearing the end of our gress will continue. The chapters on the technology of sig• careers thought it would be useful to look back and doc• nal processing, polarimetry, air and spacebome radar, and ument from whence we came, to take stock of the advances wind profiling systems are illustrative of the latest devel• which have been made since then, and to exploit our joint opments and trends and point to future system designs. wisdom in setting the agenda for the future. In accordance One of my goals as editor was to provide some sort of with these goals, both the conference and this volume were synthesis. I tried to do this mainly through the cross-ref• organized in three broad segments: history, critical reviews erencing among the various chapters, the reduction of re• of progress and status, and panel reports providing a dundancy, the filling of significant gaps, and the resolution broader perspective and a look into the future. of conflicts where desirable. In some cases, I deliberately The histories (Chapters 1-18) cover the people, events left conflicting ideas to depict the controversy that sur• and institutions that played pivotal roles during the first rounds a particular subject. For example, in several papers two decades of radar studies. In some cases the institutional about polarization diversity, opinion is divided as to and national histories bring us up to the present time. Re• whether or not measurements of differential reflectivity grettably, a report was not available from the , will enhance the accuracy of radar measurements of rain• where seminal work was done from the late 1940s. fall. I also retained many overlapping references to The reviews in Chapters 19 through 31 cover techno• NEXRAD (Next Generation Weather Radar) because they logical, scientific and operational topics. These were writ• provide differing viewpoints as to how this radar may best ten by experts in each of the subject areas. Following each be used in addressing the various problems. review is a panel report on the same subject. The latter, With minor exceptions related to format and organiza• authored by one or more scientists, represents a broad tion, I made no attempt to standardize writing style. Thus, consensus of a group of specialists who met in advance of each chapter has its own distinct flavor depending upon the conference to critique preliminary versions of the re• the style of the author. views and subsequently prepared a report aimed at pro• The book is especially timely since the field is about to viding a balanced view, filling in gaps, and identifying explode with the forthcoming widespread installation of avenues of the most promising research and development the most modem Doppler radars throughout the United for the decades ahead. States. These include the Next Generation Weather Radar, Altogether the work involved more than 200 participants UHF and VHF wind profiling radars, and Terminal Doppler and authors. The volume is therefore literally a product Weather Radars for wind shear detection. In Western Eu• of the entire community and represents a compendium of rope modem weather radars are being integrated into a knowledge in this field that is not likely to be replicated cooperative network. New operational and research sys• for many years. It will be of value to students, scientists tems have been installed in , Spain, , Japan and technologists, and members of the operational com• and the People's Republic of China, among others. The munities. It will also serve as a guidebook to decision airborne Doppler radars operated by the National Oceanic makers. and Atmospheric Administration in the United States have A glance at the Table of Contents will show that this produced dramatic research results and have stimulated book is not a provincial treatise on radar meteorology. Al• the development of new airborne systems both in the though the technological chapters deal explicitly with var• United States and . Also, the emerging plans to place ious aspects of the instruments, the remaining chapters rain-measuring radars on promise unprecedented discuss a broad spectrum of scientific and operational observational capabilities. problems in meteorology. In this sense the reviews and These initiatives are already creating a demand for a panel reports are problem oriented. Indeed, in most cases new generation of broadly based researchers· with ad• radar is treated as only one of the required tools. The papers vanced skills in the radar arts and for operational meteo• cover scientific subjects ranging from cloud microphysics rologists-capable of exploiting the modem technology. We and dynamics to aspects of global , and operational expect that this compendium will contribute strongly to- ix ward these ends. The large number of new systems will The one discouraging factor in this otherwise exciting also increase the amount of observational data by several picture is the failure of our universities to train adequate orders of magnitude in the next decade, thereby providing numbers of scientists in the instrumental and observational a very rich source of new material to the science community aspects of meteorology in order to meet future needs. We which will surely lead to new insights and discoveries. hope that this volume will help to stimulate the academic When viewed in the context of the striking advances community to rectify this situation. taking place in parallel fields of space observations, com• While this book and the conference from which it grew puter technology, communications, information handling have dominated the last three years of my life, I am grat• and display, and numerical modeling of meteorological ified by how much I have learned, by the satisfaction of and oceanic phenomena, the outlook for the future is having participated in setting the foundations for the fu• breathtaking. The existing activities under the World Cli• ture, and the exquisite joy of seeing how far we have come mate Research Program, the emerging activities for study• since I started on the road of radar in meteorology 45 ing atmosphere-oceans-land as an integrated system, and years ago. the rich variety of planned and ongoing experiments on storm and mesoscale problems provide the stage on which much of the research and operational activity will be David Atlas played out. Editor

X Acknowledgments

The Battan Memorial and 40th Anniversary Conference mann of ST Systems (STX) Corporation and Frank Rug• of Radar Meteorology and this volume were made possible giero of AFGL, all of whom exerted themselves above and in part through the generous support of the following beyond normal expectations. Albert Chmela (AFGL, re• agencies: tired) arranged the nostalgic "Old Timers" evening. The fun of the mock awards ceremony was due largely to the National Science Foundation preparation of cartoons by Dr. Ronald Rinehart of the National Aeronautics and Space Administration University of , aided by an anonymous com• National Oceanic and Atmospheric Administration mittee of three who created the awards, and by Harriet Office of Naval Research Chmela who arranged appropriate music. Denny Donald• U.S. Air Force Office of Scientific Research son's enthusiastic guidance to the many interesting sights of Boston made the meeting particularly enjoyable for the The Air Force Geophysics Laboratory (Hanscom Field) spouses. was also particularly gracious in supporting the conference A notable and poignant contribution was made by Prof. travel of many senior scientists who had previously been Philip Krider, on behalf of the Institute of Atmospheric associated with its Weather Radar Branch either as staff Physics, University of Arizona, in the form of a bound members or grantees. This combined support permitted collection of the works of Lou Battan which was presented the participation of many persons who would not other• to Jeanette Battan during the conference. Lou's wise have been able to attend the conference. The staff of daughter, Suzette, had spent several months painstakingly sifting the AFGL Weather Radar Facility and its associated con• through his papers and assembling them. tractors were also instrumental in all the activities before, The lion's share of acknowledgments must during and after the conference, and in the preparation of go to the this volume. authors of the histories and critical review papers, without whom neither the conference nor this volume would have We are also indebted to the following firms for contri• been possible. We also owe deep butions to assist the conduct of the conference: thanks to the many panel members and the panel chairman who did so much to Aeromet, Inc. stimulate interest and to round out this treatise. Dr. Robert Alden Electronics J. Serafin of NCAR was most helpful, especially in orga• Enterprise Electronics nizing the technological sessions and reviews. Pauline Raytheon Company Austin, former director of the MIT Weather Radar Project, SigmetjLassen Research assisted importantly as a reviewer of several manuscripts. Tycho Technology I am most grateful to Donna Velardi of AFGL who typed the voluminous announcements and correspondence con• We particularly appreciate the additional support of nected with the conference as well as a number of the UNISYS in subsidizing the book's dust jacket, and of manuscripts, and to Shelley Zucker, Carol Nicolaidis, Vic• NCAR in providing the striking radar photos for the front toria Holzhauer and Regina Gregory of NCAR for prep• and back covers. aration of the unified reference list. The attractive dust We are especially grateful to Richard E. Carbone who jacket is due to the professional service volunteered by was Chairman of the AMS Committee on Radar Meteo• Helga Hardy. Mrs. Quy Philpot of Centel Federal Services rology through most of the period involved, the Confer...: Corporation, supported by NASA, also performed yeoman ence Organizing Committee, and the Local Arrangements services during the final stages of preparation of the book. Committee. Members of these committees are listed below. I am also pleased to acknowledge the immense, first• One of the highlights of the conference was an exhibit rate job of copy editing done by Laura Westlund and the of "Radar as Art," arranged through the voluntary assis• technical editing by Dr. Harold Nagel, both of the Amer• tance of Dr. Harold Baynton and Linda Carbone, with the ican Meteorological Society. Also, Executive Director support of NCAR. The National Center for Atmospheric Emeritus Kenneth Spengler and Evelyn Mazur guided us Research was also instrumental in providing arrangements wisely through the entire process. and facilities for the advance meetings of the panels. My deepest personal appreciation goes to Ralph J. Don• The success of the conference was due in large part to aldson of STX Corporation (working with the AFGL the dedicated efforts of Dr. Alan Bohne of AFGL, Chair• Weather Radar Facility), my friend and colleague of about man of the Local Arrangements Committee, who looked 40 years, and my faithful, imaginative and dedicated co• after the myriad of details. The unique structure of the chairman of the conference. Ralph also took the initiative conference and the social functions posed novel challenges to edit a number of the manuscripts and advised me on to Alan and his colleagues, Paul Desrochers and Don Ha- many others. Without his continuing help and encourage-

xi ment this work could not have been accomplished nearly PROGRAM COMMITTEE so well. David Atlas, Co-Chairman Richard Doviak Finally, I must thank my wife Lucille, who assisted me Richard Carbone Ralph Donaldson, throughout this project. Her understanding and love have Kerry Emanuel Co-Chairman supported all my endeavors. Kenneth Gage Kenneth Glover Richard Passarelli Roddy Rogers Robert Abbey AMS 1987 COMMITTEE ON RADAR METEOROLOGY LOCAL ARRANGEMENTS COMMITTEE Richard Carbone, Chairman Edward Brandes Kenneth Gage Joseph Golden Alan Bohne, Chairman Albert Chmela David Jorgensen Frank Marks Denny Donaldson Spiros Geotis Jacques Testud Carlton Ulbrich Ian Harris Lou McNally Albert Waldvogel Ronald Rinehart

xii Tribute to Professor Louis J. Hattan

Dr. Louis J. Battan died on October 29, 1986, after a short illness. Although he had been a professor of atmo• spheric sciences at the University of Arizona since 1958 and director of the Institute of Atmospheric Physics there from 1973 to 1982 (and associate director from 1958 to 1973), his activities on the national and international scenes were so varied that he was known in different ways by the numerous communities with which he was in• volved. However, all who knew him shared his uncom• monly good humor, took pride in his friendship, and re• spected his wisdom and good judgment. Lou is survived by his wife Jeanette, daughter Suzette, and son Paul. Battan was born in City on February 9, 1923. He was the second of four sons born to Annibale and Luisa Battan, immigrants to the United States from the village of Vigo in the Tyrolean Alps of Austria. He grew up in , New York, in a family environment that encouraged the highest moral standards and a devotion to hard work and self-reliance, qualities that remained with him throughout his life. Lou began college as a mechanical engineering major at the City College of New York in 1941. Sometime during this period, he took and passed the examination for the Fire Department, thinking that this would to studies he was unbeatable. I remember many an evening be useful as a fall back position. A World War II recruiting in the summer of 1943 when he and Dave Lowenthal (now poster brought him into the Army Air Corps aviation cadet at Boston College, Boston, Massachusetts) sat on the fire program in meteorology. I met him on the New York sub• escape testing one another in preparation for our daily way on March 8, 1943, as we were both beginning our quiz. This kind of discipline rubbed off on others in the service with 15 months of study at New York University apartment, so it was more than coincidental that the three (NYU) . Matching the name on my suitcase to the first of us ended in the top ten at graduation. Following our name on the list of his Army orders assigning us to NYU, commissioning as second lieutenants, we three were also Lou introduced himself, and in the short walk from the selected to go on to radar school at station to the University Heights campus, we decided to and the Massachusetts Institute of Technology (MIT; both room together if permitted. Thus began 43 years of friend• in Cambridge, Massachusetts). and two careers in meteorology. From March 8, 1943, The intensity of the NYU meteorology program was only until we received our commissions on June 5, 1944, we a faint foreshadow of what we were to endure in nine lived, studied, and marched together. Indeed, we probably months of radar training at Harvard and MIT. It is no would have been together anyway because of the Army's exaggeration that those few months equalled about two penchant for conducting business in alphabetical order. years of peacetime education in radio engineering. Sur• Our days of meteorological training at NYU were any• prisingly, we retained much of what we were taught. Al• thing but easy. In fact, our instructors were so tough on though we did not appreciate it at the time, we were among us that we often regarded them as the enemy. Little did the privileged "100" weather officers who were also trained we realize that at least four of them were to become cher• in radar. This group was the cadre that then went out into ished friends and greats in meteorology-Hans Panofsky the field to set up and operate the SCR-584s for wind (Pennsylvania State University, University Park), Yale finding and the APQ-13s for both ground-based storm Mintz (University of California, Los Angeles), Bob Fleagle detection and airborne weather reconnaissance. While only (University of Washington, Seattle), and Bill Gordon (Rice three of us remained in what was to become radar mete• University, Houston, ). orology, it became clear some years later that this dual Lou, a devout Catholic, set the moral tone for the eight disciplinary training was responsible for our innovative of us who occupied the apartment at 1950 Andrews Av• abilities. This lesson deserves to be reemphasized now, enue adjacent to the campus. To be sure, he was not the when we are beginning to have doubts about the source most conscientious soldier in the class, but when it came of the next generation of instrumentally oriented meteo- xiii rologists. After radar school, Lou went on to set up a ments. Later, he also studied Russian, motivated by the weather radar at Panama City (Eglin Field), Florida, and accelerating activities in weather modification in the Soviet was later stationed at bases in Texas, Arizona, and Puerto Union. He subsequently served on several U.S. delegations Rico. to the Soviet Union and utilized this talent to write anum• Upon his discharge from active duty in 1946, Lou re• ber of review papers on the state of Soviet , turned to NYU and obtained his B.S. degree in meteorol• weather modification, and radar meteorology. These ac• ogy. He joined the U.S. Weather Bureau and was then tivities helped establish him as the world expert on Soviet assigned to the Thunderstorm Project at the University of research in these realms. Chicago. He earned his M.S. degree there in 1949. Lou was catapulted to the forefront of the field of With the end of the war, a number of the leaders of weather modification research as a result of his personal meteorology recognized the unprecedented opportunity expertise in this area and his deep familiarity with similar to attack one of the great hazards to flight safety-the work in the Soviet Union. He thus played an active role thunderstorm-by using Second World War technology, in writing the 1973 National Academy of Sciences report mainly aircraft and radar. With the eager cooperation of on the subject. Subsequently, he served on many weather the Air Corps and the U.S. Weather Bureau, the Thun• modification advisory groups. derstorm Project was born. Two field programs were car• In 1958, Lou joined the faculty of the University of Ar• ried out. The first was centered around Pinecastle near izona as Associate Director of the Institute of Atmospheric Orlando, Florida, in 1946, and the second was near Wil• Physics and Professor of Meteorology. During his early mington, Ohio, in 1947. Clinton County Air Force Base in years at the University of Arizona, Lou and Professor Dick Wilmington was the home of the All Weather Flying Di• Kassander, his fellow associate director of the institute, led vision, where I remained as a civilian scientist after my a seven-year randomized cloud seeding program that be• own discharge from the Army. It was there that Lou and came a model for the design of many other weather mod• I were again brought together during the second field phase ification programs. In 1973, he was appointed Head of the of the Thunderstorm Project. Department of Atmospheric Sciences and Director of the The Thunderstorm Project was the prototype of the Institute of Atmospheric Physics, posts he held until1982. large-scale field experiments that became increasingly Dick Kassander recalls the many times he found himself common in the postwar years. It was unique in many ways, drowning and depressed under the ever-increasing load most importantly, perhaps, in the coordinated use of radar, of paperwork. He writes, "Lou would come in, note the an extensive ground network of meteorological stations, situation, and with a big grin, he'd stretch out his long and storm-penetrating P-61 "Black Widow" aircraft. The arms and carry it all away. In short order, he would be project produced a quantum jump in our knowledge of back with a few pieces of paper to replace the previous , but there was much more to come in later mess." Indeed, Lou's administrative and organizational years. "The Thunderstorm," the report that resulted from skills were quickly recognized and called upon frequently. the project (by Horace Byers and Roscoe Braham of the Lou remained an active member of the department and , with contributions by Lou and oth• institute until his death. ers), remains a classic today, although some of the concepts It was to the area of radar meteorology that Lou would put forth there have since been elaborated (Byers and Bra• devote a good deal of his time and energies. One of the ham, 1949). main themes of this research was the radar backscatter Lou left the Weather Bureau in 1951 but remained at from hail, first in collaboration with Ben Herman (now at the University of Chicago, completing his Ph.D. in 1953 the University of Arizona, Tucson) in the 1960s and, more and serving on the faculty until 1958. His dissertation, recently, with Craig Bohren, now at Pennsylvania State "Observations on the Formation of Precipitation in Con• University. In this regard, it was a curious coincidence that vective Clouds," was based upon TPS-10 radar data from brought our scientific paths together again in 1959. Let me the 1947 phase of the Thunderstorm Project. Braham set down this part of the story in Lou's own words, which counts this work as the first definitive identification of the he tape-recorded for me on October 8, just three weeks coalescence mode of precipitation growth in warm con• before his death. vective clouds. Subsequently, these findings were con• firmed by studies in Puerto Rico, the central United States, and Arizona. It was during this period that Battan worked You asked about the Herman and Browning work, and I with Byers and Braham on the artificial nucleation of cu• must say that was a very exciting time. The history of that mulus clouds, and the triumvirate became known as the work on the backscattering from hail started this way. Ben "three B's" in the cloud physics community. Some of this Herman, who was then a graduate student, was working on appears in the paper by the three B's that appeared in the scattering of radiation by cloud droplets. He 1957 (Braham et al., 1957). had programmed the Mie scattering equations and came Lou, fluent in Italian and Spanish since childhood, stud• walking into my office one day and said that he had this ied French and German for his Ph.D. language German program and did I see any useful applications. This was the xiv time [1959] you were working in England with Frank Ludlam of the subject until the appearance of Doppler Radar and and I had gotten a letter from you saying that you had gotten Weather Observations by Doviak and Zrnic (1984). He also some exciting results, that the backscatter cross sections of wrote and coauthored elementary texts such as Weather large hail [actually, deep frozen artificial ice balls] were much ( Battan, 1984) and Fundamentals of Meteorology ( Battan, larger than you expected. So I said to Ben, "Yeah, let's run 1983a). Lou also wrote seven other popular books, ranging off some backscatter calculations for spherical ice particles from The Nature of Violent Storms (Battan, 1961) to Weather which simulate hailstones at ." Shortly thereafter, Battan, 1983b). These are important because back came the calculations showing the curves that I sent in Your Life ( you. And I must say, it was one of the big thrills of my of their straightforward style and the ease with which they scientific experience when I got your letter in which you had conveyed abstract concepts. Accordingly, they attracted a plotted your actual measurements against the curve. Ire• wide spectrum of students and nonspecialists who might member thinking to myself: Isn't this astounding, theory have been frightened off by the more esoteric treatments. and measurements are in agreement. One can hardly estimate the impact that Lou's popular books and introductory texts have had on the atmospheric Well, that thrill was occurring simultaneously on both sciences and on society through the attraction of students sides of the Atlantic. It was not only that theory and mea• to the field and through contributions to the public's un• surement agreed so well, but we all had nurtured the Ray• derstanding of science worldwide. Certainly, his contri• leigh scatter law that said that (small) ice particles scattered bution on these scores is second to none in meteorology. about one-fifth as well as equal water drops. Until then Lou used his talent for writing in conjunction with his the entire radar meteorology community had either for• research abilities to produce a large number of other pub• gotten or ignored the 1941 work of Ryde (1946), which lications as well. Beginning with the journal article "The showed that spheres of ice became better scatterers than Use of Radar in Determining the Amount of Rain Falling those of water at diameters greater than about 0.6 wave• over a Small Area" (Battan, 1948), he produced over 100 lengths. scientific papers and reports and an additional 100 pub• The thrill of discovery and serendipitous confluence of lished items in encyclopedias, periodicals, and newspapers. separately derived ideas punctuate much of science. Theory In spite of his extensive achievements as a scientist and a and experiment done 6000 miles (10 000 km) apart co• scholar, however, he maintained a modest posture alesced and motivated Lou to extend the Arizona calcu• throughout his career. lations to melting and spongy ice spheres over a range of With this record of accomplishments, one might have wavelengths. He continued this work on and off until his expected Lou to have taken some high post in government death. It is notable that five of his last six papers dealt or academia. Indeed, he could have, for he had received with the scattering properties of hail and snow. His last many such offers. To be sure, he was tempted on occasion paper, on the backscatter of large oblate spongy hail, was by positions from which he could exert great influence. published in 1987 (Longtin et al., 1987). However, Lou had found his niche as university professor The other realm in which Lou pioneered was Doppler and writer. He was comfortable with himself, the ways in radar. In his taped comments of October 8, 1986, he told which he could contribute, his position, and his family. me that the papers that stimulated his interest in Doppler Because of this inner peace and satisfaction, he could be were those by Boyenval (1960) and Lhermitte (1960), both called upon for advice unimpeded by ulterior motives. of which were presented at the Eighth Conference on Ra• Lou did not isolate himself in his comfortable niche, dar Meteorology in San Francisco, California, in 1960. In however. Indeed, he was called upon time and again to short order, he, Dick Kassander, and John Theiss (then at serve the national and international geophysical commu• the University of Arizona) submitted a proposal to the nities. He was a member of several early delegations to National Science Foundation to develop a 3-cm Doppler the World Meteorological Organization and the Soviet radar, and their first paper on the vertical motions and Union. He served with distinction on a long list of com• particle sizes in thunderstorms appeared in 1964 ( Battan mittees and panels of the National Academy of Sciences, et al., 1964). His scientific interests then fluctuated between including the chairman of the Committee on Atmospheric weather modification, Doppler radar, and the scattering Sciences (1973-76) and vice-chairman of the Geophysics properties of hydrometeors. Study Committee (1978-82) as well as the National Ad• I suspect that Lou would prefer to be remembered most, visory Committee on Oceans and Atmosphere (1978-81). and probably will be, for his books, of which there were Lou was also extremely influential in the founding of the 16. Most of these have been translated into several lan• National Center for Atmospheric Research (NCAR). He guages. His first book, Radar Meteorology ( Battan, 1959), served NCAR and its operating corporation, the University was a concise and lucid introduction to the subject. This Corporation for Atmospheric Research, in many ways, in• was updated and enlarged by Radar Observations of the cluding long-time service on the Board of Trustees and Atmosphere (Battan, 1973). Except for one text in Russian the Members' Representative Group, and in many advisory and another in French, and my own more modest mono• capacities. He fought staunchly to permit scientists to guide graph in 1964, these books remained the major treatments their own fates without undue direction from above, be-

XV lieving that the best science nearly always is done in an On the personal side, Lou was a raconteur of great note. unfettered, supportive atmosphere. He could often be found at the center of a group, recasting Lou was also an active leader in the affairs of both the a story of passing humor into one that elicited great laugh• American Geophysical Union and the American Meteo• ter. His sense of humor stood him in good stead in many rological Society. In AGU, he served on a variety of com• other more serious circumstances by helping to relieve the mittees and was president of the Meteorology Section tension. In addition, his colleague, Ben Herman, writes (1974-76). He was also chairman of the U.S. National that Lou was the wise old sage of the department to whom Committee of the International Association on Geodesy everyone went for advice, consolation, and encourage• and Geophysics (1980-84). He was also slated to be the ment. AGU Foreign Secretary when he took ill. On at least two Perhaps his greatest attribute is that Lou was a gentle occasions, he declined nominations for the AGU presi• person. He was thoughtful, kind, and sensitive. Never did dency. he utter a denigrating word about anyone; conversely, no His activities in the American Meteorological Society one had an unkind word to say about him. He was admired (AMS) are legend. They included service on a host of sci• and respected by all, many were proud to be numbered entific and advisory committees, the presidency (1966- among his friends, and others, like me, loved him as a 67}, chairman of the Commission on Scientific and Tech• brother. nological Activities (1970-73), and chairman of the Plan• The combination of his science, his writings, his states• ning Commission for 12 years. manship, and the esteem in which he is held constitute a Many of his contributions to meteorology were recog• legacy that few of us can hope to match. nized by the AMS. In 1962, he received the Meisinger Award "for his outstanding, imaginative and pioneering 0 may I join the choir invisible research in radar meteorology and in cloud physics"; in Of those immortal dead who live again 1971, the Charles Franklin Brooks Award for Outstanding In minds made better by their presence Services to the Society "in recognition and appreciation for his imaginative, wise, and good-humored leadership -George Eliot during many years of service as Councilor and President "0 May I Join the Choir Invisible" of the Society"; and in 1975, the Second Half Century Award "for his many contributions to cloud physics and his objective scientific evaluation of weather modification David Atlas* efforts, his writings fostering public understanding of me• Department of Meteorology, University of teorology, and his greater service to the profession in many capacities." His daughter Suzette told me that he was es• Reprinted from Eos, Vol. 68, 656 and 676. pecially proud of his election as an honorary member of the AMS in early October 1986, just a few weeks before his death. • Presently, independent consultant, Bethesda, Maryland.

References

Battan, L.J., 1959: Radar Meteorology. University of Chicago --, 1984: Weather. 2nd ed., Prentice-Hall. Press. --, 1961: The Nature of Violent Storms. Doubleday. --, J.B. Theiss and A.R. Kassander, Jr., 1964: Some Doppler radar observations of a decaying thunderstorm. --, 1973: Radar Observations of the Atmosphere. Univer- Proc. 11th Weather Radar Conf., Boulder, Amer. Meteor. sity of Chicago Press. Soc., 362-365. --, 1983a: Fundamentals of Meteorology. 2nd ed., Pren• Boyenval, E.H., 1959: Echoes from precipitation using tice-Hall. pulsed Doppler radar. Proc. Eighth Conf. on Radar Me• --, 1983b: Weather in Your Life. W.H. Freeman. teorology, San Francisco, Amer. Meteor. Soc., 57-64.

xvi Braham, R.R., Jr., L.J. Battan and H.R. Byers, 1957: The Lhermitte, R.M., 1959: The use of special "pulsed Doppler artificial nucleation of cumulus clouds. Meteor. Monogr.; radar" in measurements of particle fall velocities. Proc. Amer. Meteor. Soc., 2, 47. Eighth Conf. on Radar Meteorology, San Francisco, Amer. Byers, H.R., and R.R. Braham, Jr., 1949: The thunderstorm. Meteor. Soc., 269-275. Rep. NTIS PB 234515, U.S. Dept. of Commerce, Wash• ington DC. Longtin, D.R., C.F. Bohren and L.J. Battan, 1987: Radar backscattering by large, spongy, ice oblate spheroids. J. --, et al., 1948: The use of radar in determining the Atmos. Oceanic Techno/., 4, 355-358. amount of rain falling over a small area. Eos Trans. AGU, 29, 187-196. Ryde, J.W., 1946: Attenuation of centimeter radio waves Doviak, R.J., and D.S. Zrnic, 1984: Doppler Radar and and the intensities resulting from atmospheric Weather Observations. Academic Press. phenomena. J. Inst. Electr. Eng. , 3A, 93, 101.

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