Table of Contents

Preface vii 1 Introduction 1 2 Ice Crystal Gallery 9 3 The Beginnings of Halo Science 21 4 How Halos Form 33 5 Halo Simulations 43 6 Halos From Prismatic Crystals 51 7 Odd Radius Halos Are Real 65 8 Odd Radius Circular Halos 71 9 Some Crystallography 91 10 Pyramidal Ice Crystals 101 11 The Search For Angle x 113 12 Refraction Halos and Wedge Angle 129 13 The Spin Vector 133 14 A User's Guide To Halo Poles 137 15 Odd Radius Plate Arcs 145 16 Odd Radius Column Arcs 165 17 Odd Radius Parry Arcs 179 18 Other Wedge Angles? 183 Appendix A: Pattern for Crystal Model 195 Appendix B: Halo Terminology 197 Appendix C: Halo Observation and Photography 199 Appendix D: From Pixels to Degrees 203 Appendix E: More Crystallography 211 ppendix F: Living on the (w)Edge 219 Bibliography 227 Index 233