Radiation Zone
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Institute for Nuclear Study University of Tokyo Tanashi, Tokyo 188, Japan And
lNS-Rep.-645 INSTITUTE FOR NUCLEAR STUDY . UNIVERSITY OF TOKYO Sept 1987 Tanashi, Tokyo 188 Japan Resonant Spin-Flavor Precession of k Solar and Supernova Neutrinos Chong-Sa Lim and William J. Marciano •3300032376 INS-Rep.-645 Sept. 1987 Resonant Spin-Flavor Precession of Solar and Supernova Neutrinos Chong-Sa Lin Institute for Nuclear Study University of Tokyo Tanashi, Tokyo 188, Japan and William J. Mareiano Brookharen National Laboratory Upton. New Kork 11973, U.S.A. Abstract: The combined effect of natter and aagnetic fields on neutrino spin and flavor precession is examined. We find a potential new kind of resonant solar neutrino conversion \>_ * eL v or vT (for Dirac neutrinos) or «e *• « or vT (for Hajorana R R neutrinos). Such a resonance could help account for the lower than' expected solar neutrino v flux and/or Indications of an antl-oorrelatlon between fluctuations in the v( flux and sunspot activity. Consequences of spin-flavor precession for supernova neutrinos are also briefly discussed. - 1 - There has been a longstanding disagreement between the solar neutrino v_ flux monitored by B. Davis"" and collaborators Average Flux - 2.1 i 0.3 SHU , (1) (1 SNU - 10*' captures/s-atom) 7 37 via the reaction \>e • ' Cl •• «" • Ar and Bahcall'a standard solar model prediction Predicted Flux - 7.9 ± 2.5 SNU <3o errors) . <2) That discrepancy has come to be known as the solar neutrino puzzle. Attempts to resolve It have given rise to many speculative Ideas about unusual properties of neutrinos and/or the solar interior. One rather recently proposed solution, the MSW"-' (Mlkheyev, Snlrnov, Wolfensteln) effect is particularly elegant. -
Doc.10100.Space Weather Manual FINAL DRAFT Version
Doc 10100 Manual on Space Weather Information in Support of International Air Navigation Approved by the Secretary General and published under his authority First Edition – 2018 International Civil Aviation Organization TABLE OF CONTENTS Page Chapter 1. Introduction ..................................................................................................................................... 1-1 1.1 General ............................................................................................................................................... 1-1 1.2 Space weather indicators .................................................................................................................... 1-1 1.3 The hazards ........................................................................................................................................ 1-2 1.4 Space weather mitigation aspects ....................................................................................................... 1-3 1.5 Coordinating the response to a space weather event ......................................................................... 1-3 Chapter 2. Space Weather Phenomena and Aviation Operations ................................................................. 2-1 2.1 General ............................................................................................................................................... 2-1 2.2 Geomagnetic storms .......................................................................................................................... -
Structure and Energy Transport of the Solar Convection Zone A
Structure and Energy Transport of the Solar Convection Zone A DISSERTATION SUBMITTED TO THE GRADUATE DIVISION OF THE UNIVERSITY OF HAWAI'I IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN ASTRONOMY December 2004 By James D. Armstrong Dissertation Committee: Jeffery R. Kuhn, Chairperson Joshua E. Barnes Rolf-Peter Kudritzki Jing Li Haosheng Lin Michelle Teng © Copyright December 2004 by James Armstrong All Rights Reserved iii Acknowledgements The Ph.D. process is not a path that is taken alone. I greatly appreciate the support of my committee. In particular, Jeff Kuhn has been a friend as well as a mentor during this time. The author would also like to thank Frank Moss of the University of Missouri St. Louis. His advice has been quite helpful in making difficult decisions. Mark Rast, Haosheng Lin, and others at the HAO have assisted in obtaining data for this work. Jesper Schou provided the helioseismic rotation data. Jorgen Christiensen-Salsgaard provided the solar model. This work has been supported by NASA and the SOHOjMDI project (grant number NAG5-3077). Finally, the author would like to thank Makani for many interesting discussions. iv Abstract The solar irradiance cycle has been observed for over 30 years. This cycle has been shown to correlate with the solar magnetic cycle. Understanding the solar irradiance cycle can have broad impact on our society. The measured change in solar irradiance over the solar cycle, on order of0.1%is small, but a decrease of this size, ifmaintained over several solar cycles, would be sufficient to cause a global ice age on the earth. -
Stability of Toroidal Magnetic Fields in Rotating Stellar Radiation Zones
A&A 478, 1–8 (2008) Astronomy DOI: 10.1051/0004-6361:20077172 & c ESO 2008 Astrophysics Stability of toroidal magnetic fields in rotating stellar radiation zones L. L. Kitchatinov1,2 and G. Rüdiger1 1 Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482, Potsdam, Germany e-mail: [lkitchatinov;gruediger]@aip.de 2 Institute for Solar-Terrestrial Physics, PO Box 291, Irkutsk 664033, Russia e-mail: [email protected] Received 26 January 2007 / Accepted 14 October 2007 ABSTRACT Aims. Two questions are addressed as to how strong magnetic fields can be stored in rotating stellar radiation zones without being subjected to pinch-type instabilities and how much radial mixing is produced if the fields are unstable. Methods. Linear equations are derived for weak disturbances of magnetic and velocity fields, which are global in horizontal dimen- sions but short–scaled in radius. The linear formulation includes the 2D theory of stability to strictly horizontal disturbances as a special limit. The eigenvalue problem for the derived equations is solved numerically to evaluate the stability of toroidal field patterns with one or two latitudinal belts under the influence of rigid rotation. Results. Radial displacements are essential for magnetic instability. It does not exist in the 2D case of strictly horizontal disturbances. Only stable (magnetically modified) r-modes are found in this case. The instability recovers in 3D. The minimum field strength Bmin for onset of the instability and radial scales of the most rapidly growing modes are strongly influenced by finite diffusion, the scales are indefinitely short if diffusion is neglected. The most rapidly growing modes for the Sun have radial scales of about 1 Mm. -
The Sun and the Solar Corona
SPACE PHYSICS ADVANCED STUDY OPTION HANDOUT The sun and the solar corona Introduction The Sun of our solar system is a typical star of intermediate size and luminosity. Its radius is about 696000 km, and it rotates with a period that increases with latitude from 25 days at the equator to 36 days at poles. For practical reasons, the period is often taken to be 27 days. Its mass is about 2 x 1030 kg, consisting mainly of hydrogen (90%) and helium (10%). The Sun emits radio waves, X-rays, and energetic particles in addition to visible light. The total energy output, solar constant, is about 3.8 x 1033 ergs/sec. For further details (and more accurate figures), see the table below. THE SOLAR INTERIOR VISIBLE SURFACE OF SUN: PHOTOSPHERE CORE: THERMONUCLEAR ENGINE RADIATIVE ZONE CONVECTIVE ZONE SCHEMATIC CONVECTION CELLS Figure 1: Schematic representation of the regions in the interior of the Sun. Physical characteristics Photospheric composition Property Value Element % mass % number Diameter 1,392,530 km Hydrogen 73.46 92.1 Radius 696,265 km Helium 24.85 7.8 Volume 1.41 x 1018 m3 Oxygen 0.77 Mass 1.9891 x 1030 kg Carbon 0.29 Solar radiation (entire Sun) 3.83 x 1023 kW Iron 0.16 Solar radiation per unit area 6.29 x 104 kW m-2 Neon 0.12 0.1 on the photosphere Solar radiation at the top of 1,368 W m-2 Nitrogen 0.09 the Earth's atmosphere Mean distance from Earth 149.60 x 106 km Silicon 0.07 Mean distance from Earth (in 214.86 Magnesium 0.05 units of solar radii) In the interior of the Sun, at the centre, nuclear reactions provide the Sun's energy. -
198Lapj. . .243. .945G the Astrophysical Journal, 243:945-953
.945G .243. The Astrophysical Journal, 243:945-953, 1981 February 1 . © 1981. The American Astronomical Society. All rights reserved. Printed in U.S.A. 198lApJ. CONVECTION AND MAGNETIC FIELDS IN STARS D. J. Galloway High Altitude Observatory, National Center for Atmospheric Research1 AND N. O. Weiss Sacramento Peak Observatory2 Received 1980 March 10; accepted 1980 August 18 ABSTRACT Recent observations have demonstrated the unity of the study of stellar and solar magnetic fields. Results from numerical experiments on magnetoconvection are presented and used to discuss the concentration of magnetic flux into isolated ropes in the turbulent convective zones of the Sun or other late-type stars. Arguments are given for siting the solar dynamo at the base of the convective zone. Magnetic buoyancy leads to the emergence of magnetic flux in active regions, but weaker flux ropes are shredded and dispersed throughout the convective zone. The observed maximum field strengths in late-type stars should be comparable with the field (87rp)1/2 that balances the photospheric pressure. Subject headings: convection — hydrodynamics — stars: magnetic — Sun : magnetic fields I. INTRODUCTION In § II we summarize the results obtained for simplified The Sun is unique in having a magnetic field that can be models of hydromagnetic convection. The structure of mapped in detail, but magnetic activity seems to be a turbulent magnetic fields is then described in § III. standard feature of stars with deep convective envelopes. Theory and observation are brought together in § IV, Fields of 2000 gauss or more have been found in two where we discuss the formation of isolated flux tubes in late-type main sequence stars (Robinson, Worden, and the interior of the Sun. -