Helicities in Geophysics, Astrophysics, and Beyond

Presents cutting-edge studies of helicities from different research fields Helicities play essential roles in numerous geophysical, astrophysical, and magnetohydrodynamic phenomena, thus are studied from various disciplinary viewpoints. Helicities in Geophysics, Astrophysics, and Beyond draws together experts from different research fields to present an interdisciplinary and integrated approach to helicity studies. This synthesis advances understanding of the fundamental physical processes underlying various helicity-related phenomena. Volume highlights include: Concise introduction to fundamental properties of helicities Recent developments and achievements in helicity studies Perspectives from different fields including geophysics, space physics, solar physics, plasma physics, atmospheric and nonlinear sciences A cohesive mathematical, physical, observational, experimental, and numerical strategy for helicity studies A synthesized framework for the application of helicity to real-world problems The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.

Presents cutting-edge studies of helicities from different research fieldsHelicities play essential roles in numerous geophysical, astrophysical, and magnetohydrodynamic phenomena, thus are studied from various disciplinary viewpoints.Helicities in Geophysics, Astrophysics, and Beyond draws together experts from different research fields to present an interdisciplinary and integrated approach to helicity studies. This synthesis advances understanding of the fundamental physical processes underlying various helicity-related phenomena.Volume highlights include:* Concise introduction to fundamental properties of helicities* Recent developments and achievements in helicity studies* Perspectives from different fields including geophysics, space physics, solar physics, plasma physics, atmospheric and nonlinear sciences* A cohesive mathematical, physical, observational, experimental, and numerical strategy for helicity studies* A synthesized framework for the application of helicity to real-world problemsThe American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.

List of contributors viiPreface ixPart I Helicity Essentials: Basic and Fundamental Concepts 11 Introduction to Field Line Helicity 3Anthony R. Yeates and Mitchell A. Berger2 Magnetic Winding: Theory and Applications 17David MacTaggart3 Transport in Helical Fluid Turbulence 25Nobumitsu YokoiPart II Helicity Manifestations in Nature and Their Observations 514 Observations of Magnetic Helicity Proxies in the Solar Photosphere: Helicity With Solar Cycles 53Hongqi Zhang, Shangbin Yang, Haiqing Xu, Xiao Yang, Jie Chen, and Jihong Liu5 Chirality of Solar Filaments and the Supporting Magnetic Field 75Peng-Fei Chen6 Solar Flares and Magnetic Helicity 83Shin Toriumi and Sung-Hong Park7 Magnetic Helicity Measurements in the Solar Wind 105Yasuhito Narita8 Magnetic Helicity in Rotating Neutron Stars 117Maxim Dvornikov9 Writhing From Biophysics to Solar Physics and Back 133Christopher Prior and Arron N. Bale10 Kinetic Helicity in the Earth's Atmosphere 149Otto Chkhetiani and Michael KurganskyPart III Theoretical and Numerical Helicity Modeling 16711 Effects of P-Noninvariance, Particles, and Dynamos 169Victor B. Semikoz and Dmitry D. Sokoloff12 Stability of Plasmas Through Magnetic Helicity 179Simon Candelaresi and Fabio Del Sordo13 Helicity-Conserving Relaxation in Unstable and Merging Twisted Magnetic Flux Ropes 189Philippa K. Browning, Mykola Gordovskyy, and Alan W. Hood14 Emergence of Magnetic Structure in Supersonic Isothermal Magnetohydrodynamic Turbulence 203Jean-Mathieu Teissier and Wolf-Christian Müller15 Nonlinear Mean-Field Dynamos With Magnetic Helicity Transport and Solar Activity: Sunspot Number and Tilt 217Nathan Kleeorin, Kirill Kuzanyan, Igor Rogachevskii, and Nikolai Safiullin16 The Spatial Segregation of Kinetic Helicity in Geodynamo Simulations 241Avishek Ranjan and Peter DavidsonIndex 259