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Solar Modulation Effect on Galactic Cosmic Rays
Solar Modulation Effect On Galactic Cosmic Rays Cristina Consolandi – University of Hawaii at Manoa Nov 14, 2015 Galactic Cosmic Rays Voyager in The Galaxy The Sun The Sun is a Star. It is a nearly perfect spherical ball of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process. 3 The Sun & The Heliosphere The heliosphere contains the solar system GCR may penetrate the Heliosphere and propagate trough it by following the Sun's magnetic field lines. 4 The Heliosphere Boundaries The Heliosphere is the region around the Sun over which the effect of the solar wind is extended. 5 The Solar Wind The Solar Wind is the constant stream of charged particles, protons and electrons, emitted by the Sun together with its magnetic field. 6 Solar Wind & Sunspots Sunspots appear as dark spots on the Sun’s surface. Sunspots are regions of strong magnetic fields. The Sun’s surface at the spot is cooler, making it looks darker. It was found that the stronger the solar wind, the higher the sunspot number. The sunspot number gives information about 7 the Sun activity. The 11-year Solar Cycle The solar Wind depends on the Sunspot Number Quiet At maximum At minimum of Sun Spot of Sun Spot Number the Number the sun is Active sun is Quiet Active! 8 The Solar Wind & GCR The number of Galactic Cosmic Rays entering the Heliosphere depends on the Solar Wind Strength: the stronger is the Solar wind the less probable would be for less energetic Galactic Cosmic Rays to overcome the solar wind! 9 How do we measure low energy GCR on ground? With Neutron Monitors! The primary cosmic ray has enough energy to start a cascade and produce secondary particles. -
NASA Calls for Suggestions to Rename Future Telescope Mission Pg 8
National Aeronautics and Space Administration www.nasa.gov Volume 4, Issue 3 February 2008 View NASA Calls for Suggestions to Rename Future Telescope Mission Pg 8 Dr. King Ceremony Reflects on Keeping the Dream Alive Pg 5 NASA’s Deep Impact Begins Hunt for Alien Worlds Pg 9 Goddard 02 Hubble ’s In-Flight Guidance from Table of Contents the Ground Goddard Updates By Robert Garner Hubble ’s In-Flight Guidance from the Ground - 2 Construction Update #1 on NASA Goddard’s New The Hubble Space Telescope has logged millions of miles and taken Science Building - 4 thousands of pictures since its launch in 1990, thanks in part to the Dr. King Ceremony Reflects on Keeping the Dream around-the-clock efforts of a small group of dedicated engineers and Alive - 5 Update 46th Goddard Symposium—Premiere AAS Event - 6 technicians at NASA’s Goddard Space Flight Center in Greenbelt, Md. The Innovative Partnerships Program Quiz: Headquarter’s IPP Seed Fund - 7 “Hubble is a truly amazing telescope, but as sophisticated as it is, it can’t function NASA Calls for Suggestions to Rename Future completely on its own,” said Hubble Operations Manager Mike Prior at Goddard. Telescope Mission - 8 “That’s why technicians provide around-the-clock support in the Mission Operations NASA’s Deep Impact Begins Hunt for Alien Worlds - 9 Room Command Center.” GLAST’s Delta II Rocket’s First Stage Arrives in Cape Canaveral - 10 It’s up to the Mission Operations staff to upload the commands to Hubble that tell it where to point and when, what sensing instruments to use, and when to send data Goddard Family back to Earth. -
Radial Variation of the Interplanetary Magnetic Field Between 0.3 AU and 1.0 AU
|00000575|| J. Geophys. 42, 591 - 598, 1977 Journal of Geophysics Radial Variation of the Interplanetary Magnetic Field between 0.3 AU and 1.0 AU Observations by the Helios-I Spacecraft G. Musmann, F.M. Neubauer and E. Lammers Institut for Geophysik and Meteorologie, Technische Universitiit Braunschweig, Mendelssohnstr. lA, D-3300 Braunschweig, Federal Republic of Germany Abstract. We have investigated the radial dependence of the radial and azimuthal components and the magnitude of the interplanetary magnetic field obtained by the Technical University of Braunschweig magnetometer experiment on-board of Helios-1 from December 10, 1974 to first perihelion on March 15, 1975. Absolute values of daily averages of each quantity have been employed. The regression analysis based on power laws leads to 2.55 y x r- 2 · 0 , 2.26 y x r- i.o and F = 5.53 y x r- i. 6 with standard deviations of 2.5 y, 2.0 y and 3.2 y for the radial and azimuthal components and magnitude, respectively. Here r is the radial distance from the sun in astronomical units. The results are compared with results obtained for Mariners 4, 5 and 10 and Pioneers 6 and 10. The differences are probably due to different epochs in the solar cycle and the different statistical techniques used. Key words: Interplanetary magnetic field - Helios-1 results. Introduction The study of the vanat10n of the components and magnitude of the in terplanetary magnetic field with heliocentric distance is very intersting at the present time. The mission of Mariner 10 to the inner solar system to a heliocentric distance of 0.46 AU and the missions of Pioneer 10 and Pioneer 11 to the outer solar system to heliocentric distances beyond 5 AU have provided new data over a wide range of heliocentric distance. -
Pos(ICRC2019)1148 1 GV
Evolution of geomagnetic cutoffs at the South Pole and neutron monitor rates PoS(ICRC2019)1148 Laura Rose Rosen∗ Washington State University E-mail: [email protected] Surujhdeo Seunarine University of Wisconsin-River Falls E-mail: [email protected] Neutron monitors are among the most robust and reliable detectors of GeV cosmic rays and are sensitive, with high precision, to modulations in Galactic Cosmic Rays (GCR). Hence, they can be deployed for extended periods of time, decades, and are able to observe the modulation of GCR over many solar cycles. The South Pole Neutron Monitor, located at the geographic South Pole, which is both high latitude and high altitude, has an atmospheric cutoff of around 0:1 GV. In the first four decades of its operation, a secular decline in the neutron rates have been observed. The decline may have leveled off recently. Environmental effects, including snow build up around the housing platform and the emergence and relocation of structures at the South Pole have been ruled out as causes of the decline. A recent study challenged the assumption that geomagnetic effects can be ignored at the South Pole, in particular for cosmic rays approaching from select regions in azimuth and at large zenith angles. This work confirms that ignoring geomagnetic cutoff effects could be important for the South Pole Neutron Monitor rates. We extend the investigation to include particle propagation in the Polar atmosphere, and the evolution of cosmic ray cutoffs at the South Pole over several decades. A connection is made between the evolving cutoffs and the decline in neutron monitor rates. -
Study of Intense Geomagnetic Storms and Associated Cosmic Ray
29th International Cosmic Ray Conference Pune (2005) 2, 151–154 Study of Intense Geomagnetic Storms and associated Cosmic Ray Intensity Variation ¡ ¡ Subhash C. Kaushik , A. K. Shrivastava and Hari Mohan Rajput (a) Department of Physics, Government Autonomous PG College, Datia, M P 475 661, India (b) School of Studies in Physics, Jiwaji University, Gwalior, M P 461 005, India Presenter: H. M. Rajput(subash [email protected]), ind-kaushik-SC-abs1-sh34-oral Shocks driven by energetic coronal mass ejections (CME's) and other interplanetary (IP) transients are mainly responsible for initiating large and intense geomagnetic storms. Observational results indicate that galactic cosmic rays (GCR) coming from deep surface interact with these abnormal solar and interplanetary conditions and suffer modulation effects. In this paper a systematic study has been performed to analyze the cosmic ray intensity variation during highly geoeffective conditions, referred by geomagnetic storms. These intense geomagnetic storms period have been categorized on the basis of ¢¤£¦¥ index. Study reveals the significant decrease in the cosmic ray intensity following the similar pattern as the ¢§£¨¥ index depicts. Analysis further indicates that magnitude of all the responses depend upon © component of interplanetary magnetic field (IMF) being well correlated with solar maximum and minimum periods. Transient decrease in cosmic ray intensity with slow recovery is observed during the storm phase duration. 1. Introduction Investigators have revealed that various activities taking place on Sun and other interplanetary proxies of coro- nal mass ejection's (CME's) lead to Cosmic ray (CR) modulations at neutron monitor energies. This helio- spheric modulation process reflects the dominant role played by solar wind parameters (bulk speed and the IMF intensity). -
Space and Astrophysical Plasmas: Pervasive Problems
PRAMANA c Indian Academy of Sciences Vol. 55, Nos 5 & 6 — journal of Nov. & Dec. 2000 physics pp. 645–654 Space and astrophysical plasmas: Pervasive problems CHANCHAL UBEROI Department of Mathematics, Indian Institute of Science, Bangalore 560 012, India Abstract. The observations and measurements given by Earth orbiting satellites, deep space probes, sub-orbital systems and orbiting astronomical observatories point out that there are impor- tant physical processes which are responsible for a wide variety of phenomena in solar-terrestrial, solar-system and astrophysical plasmas. In this review these topics are exemplified both from an observational and a theoretical point of view. Keywords. Heliosphere; solar corona; Alfven resonances; magnetic reconnection. PACS Nos 95.30 Q; 96.50 R 1. Introduction Space science is generally defined as investigations that are conducted by scientists using earth orbiting satellites, deep space probes like Pioneer series and sub-orbital systems. Space plasma sciences are now a very highly developed multidisciplinary area of research and can be divided into three areas: solar-terrestrial or Sun–Earth relations, solar-systems exploration and astrophysics. Though space science grew out of the rocket research which followed the end of World War II, the early investigations which began in 1946 concentrated on studies of the Earth’s atmosphere, solar radiation and cosmic rays from space. It was in 1958 that launch of Ex- plorer I and subsequent discovery of Van Allen belts which brought the scientific research in space sciences on to the list of other branches of physical and astrophysical sciences. These earlier flights of Pioneer I and subsequent series which laid the foundation of area of space plasma physics which as we now know has become a highly developed multidis- ciplinary area of research to understand the Sun–Earth or solar-terrestrial relations. -
South Pole Neutron Monitor Forecasting of Solar Proton Radiation Intensity
SPACE WEATHER, VOL. 10, S05004, doi:10.1029/2012SW000795, 2012 South Pole neutron monitor forecasting of solar proton radiation intensity S. Y. Oh,1,2 J. W. Bieber,2 J. Clem,2 P. Evenson,2 R. Pyle,2 Y. Yi,1 and Y.-K. Kim3 Received 27 March 2012; accepted 4 April 2012; published 25 May 2012. [1] We describe a practical system for forecasting peak intensity and fluence of solar energetic protons in the tens to hundreds of MeV energy range. The system could be useful for forecasting radiation hazard, because peak intensity and fluence are closely related to the medical physics quantities peak dose rate and total dose. The method uses a pair of ground-based detectors located at the South Pole to make a measurement of the solar particle energy spectrum at relativistic (GeV) energies, and it then extrapolates this spectrum downward in energy to make a prediction of the peak intensity and fluence at lower energies. A validation study based upon 12 large solar particle events compared the prediction with measurements made aboard GOES spacecraft. This study shows that useful predictions (logarithmic correlation greater than 50%) can be made down to energies of 40–80 MeV (GOES channel P5) in the case of peak intensity, with the prediction leading the observation by 166 min on average. For higher energy GOES channels, the lead times are shorter, but the correlation coefficients are larger. Citation: Oh, S. Y., J. W. Bieber, J. Clem, P. Evenson, R. Pyle, Y. Yi, and Y.-K. Kim (2012), South Pole neutron monitor forecasting of solar proton radiation intensity, Space Weather, 10, S05004, doi:10.1029/2012SW000795. -
Forbush Decreases and Turbulence Levels at Coronal Mass Ejection Fronts
A&A 494, 1107–1118 (2009) Astronomy DOI: 10.1051/0004-6361:200809551 & c ESO 2009 Astrophysics Forbush decreases and turbulence levels at coronal mass ejection fronts P. Subramanian1,H.M.Antia2,S.R.Dugad2,U.D.Goswami2,S.K.Gupta2, Y. Hayashi3, N. Ito3,S.Kawakami3, H. Kojima4,P.K.Mohanty2,P.K.Nayak2, T. Nonaka3,A.Oshima3, K. Sivaprasad2,H.Tanaka2, and S. C. Tonwar2 (The GRAPES-3 collaboration) 1 Indian Institute of Science Education and Research, Sai Trinity Building, Pashan, Pune 411021, India 2 Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India e-mail: [email protected] 3 Graduate School of Science, Osaka City University, Osaka 558-8585, Japan 4 Nagoya Women’s University, Nagoya 467-8610, Japan Received 11 February 2008 / Accepted 25 October 2008 ABSTRACT Aims. We seek to estimate the average level of MHD turbulence near coronal mass ejection (CME) fronts as they propagate from the SuntotheEarth. Methods. We examined the cosmic ray data from the GRAPES-3 tracking muon telescope at Ooty, together with the data from other sources for three closely observed Forbush decrease events. Each of these event is associated with frontside halo coronal mass ejections (CMEs) and near-Earth magnetic clouds. The associated Forbush decreases are therefore expected to have significant contributions from the cosmic-ray depressions inside the CMEs/ejecta. In each case, we estimate the magnitude of the Forbush decrease using a simple model for the diffusion of high-energy protons through the largely closed field lines enclosing the CME as it expands and propagates from the Sun to the Earth. -
Geological Survey Research 1961 Synopsis of Geologic and Hydrologic Results
Geological Survey Research 1961 Synopsis of Geologic and Hydrologic Results GEOLOGICAL SURVEY PROFESSIONAL PAPER 424-A Geological Survey Research 1961 THOMAS B. NOLAN, Director GEOLOGICAL SURVEY PROFESSIONAL PAPER 424 A synopsis ofgeologic and hydrologic results, accompanied by short papers in the geologic and hydrologic sciences. Published separately as chapters A, B, C, and D UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1961 FOEEWOED The Geological Survey is engaged in many different kinds of investigations in the fields of geology and hydrology. These investigations may be grouped into several broad, inter related categories as follows: (a) Economic geology, including engineering geology (b) Eegional geologic mapping, including detailed mapping and stratigraphic studies (c) Eesource and topical studies (d) Ground-water studies (e) Surface-water studies (f) Quality-of-water studies (g) Field and laboratory research on geologic and hydrologic processes and principles. The Geological Survey also carries on investigations in its fields of competence for other Fed eral agencies that do not have the required specialized staffs or scientific facilities. Nearly all the Geological Survey's activities yield new data and principles of value in the development or application of the geologic and hydrologic sciences. The purpose of this report, which consists of 4 chapters, is to present as promptly as possible findings that have come to the fore during the fiscal year 1961 the 12 months ending June 30, 1961. The present volume, chapter A, is a synopsis of the highlights of recent findings of scientific and economic interest. Some of these findings have been published or placed on open file during the year; some are presented in chapters B, C, and D ; still others have not been pub lished previously. -
Deep Space Chronicle Deep Space Chronicle: a Chronology of Deep Space and Planetary Probes, 1958–2000 | Asifa
dsc_cover (Converted)-1 8/6/02 10:33 AM Page 1 Deep Space Chronicle Deep Space Chronicle: A Chronology ofDeep Space and Planetary Probes, 1958–2000 |Asif A.Siddiqi National Aeronautics and Space Administration NASA SP-2002-4524 A Chronology of Deep Space and Planetary Probes 1958–2000 Asif A. Siddiqi NASA SP-2002-4524 Monographs in Aerospace History Number 24 dsc_cover (Converted)-1 8/6/02 10:33 AM Page 2 Cover photo: A montage of planetary images taken by Mariner 10, the Mars Global Surveyor Orbiter, Voyager 1, and Voyager 2, all managed by the Jet Propulsion Laboratory in Pasadena, California. Included (from top to bottom) are images of Mercury, Venus, Earth (and Moon), Mars, Jupiter, Saturn, Uranus, and Neptune. The inner planets (Mercury, Venus, Earth and its Moon, and Mars) and the outer planets (Jupiter, Saturn, Uranus, and Neptune) are roughly to scale to each other. NASA SP-2002-4524 Deep Space Chronicle A Chronology of Deep Space and Planetary Probes 1958–2000 ASIF A. SIDDIQI Monographs in Aerospace History Number 24 June 2002 National Aeronautics and Space Administration Office of External Relations NASA History Office Washington, DC 20546-0001 Library of Congress Cataloging-in-Publication Data Siddiqi, Asif A., 1966 Deep space chronicle: a chronology of deep space and planetary probes, 1958-2000 / by Asif A. Siddiqi. p.cm. – (Monographs in aerospace history; no. 24) (NASA SP; 2002-4524) Includes bibliographical references and index. 1. Space flight—History—20th century. I. Title. II. Series. III. NASA SP; 4524 TL 790.S53 2002 629.4’1’0904—dc21 2001044012 Table of Contents Foreword by Roger D. -
Mission Overview the Pioneer Mission Set the Stage for U.S. Space
Mission Overview The Pioneer mission set the stage for U.S. space exploration. Pioneer 1 was the first manmade object to escape the Earth's gravitational field. Later Pioneer 4 was the first spacecraft to fly to the moon, Pioneer 10 was the first to Jupiter, Pioneer 11 was the first to Saturn and Pioneer 12 was the first U.S. spacecraft to orbit another planet, Venus. The following table summarizes the Pioneer spacecraft and scientific objectives of the Pioneer mission. Name Launch Mission Status (as of 1998) ----------------------------------------------------------------- Pioneer 1 1958-10-11 Moon Reached altitude of 72765 miles Pioneer 2 1958-11-08 Moon Reached altitude of 963 miles Pioneer 3 1958-12-02 Moon Reached altitude of 63580 miles Pioneer 4 1959-03-03 Moon Passed by moon into solar orbit Pioneer 5 1960-03-11 Solar Orbit Entered solar orbit Pioneer 6 1965-12-16 Solar Orbit Still operating Pioneer 7 1966-08-17 Solar Orbit Still operating Pioneer 8 1967-12-13 Solar Orbit Still operating Pioneer 9 1967-11-08 Solar Orbit Signal lost in 1983 Pioneer E 1969-08-07 Solar Orbit Launch failure Pioneer10 1972-03-02 Jupiter Communication terminated 1998 Pioneer11 1972-03-02 Jupiter/Saturn Communication terminated 1997 Pioneer12 1978-05-20 Venus Entered Venus atmos. 1992-10-08 The focus of this document is on Pioneer Venus (12), the last spacecraft in a mission of firsts in space exploration. Probe Separation: Pioneer Venus separated into two spacecraft on Aug 8, 1978: an Orbiter (PVO) and a Multiprobe. The latter was separated into five separate vehicles near Venus. -
August 2020 Newsletter
Freedom’s Voice The Monthly Newsletter of the Military History Center 112 N. Main ST Broken Arrow, OK 74012 http://www.okmhc.org/ “Promoting Patriotism through the Preservation of Military History” Volume 7, Number 8 August 2020 United States Armed Services Purple Heart Recognition Day Day of Observance The significant days of observance in August are Coast Guard Birthday on the 4th and Purple Heart Recognition Day on the 7th. Museum Hours and Admission Fee Tuesday thru Friday: 10:00-4:00 Saturday: 10:00-2:00 Closed Sunday and Monday and on major Federal holi- days Adults – $5.00 Purple Heart Recognition Day on August 7 honors recipients of Members and children under 18 – Free the medal, the oldest American military decoration for military merit. Since 1944, the requirements have been limited to those For more information, call (918) 794-2712 who are wounded or killed in combat with an armed enemy. The MHC salutes Purple Heart recipients – thank you. www.okmhc.org The MHC Salutes Southwest Asia Veterans Southwest Asia Service Ribbon The southwest Asia service medal with ribbon was awarded to military personnel who served in Saudi Arabia, Kuwait, Iraq and the Persian Gulf region during the period August 2, 1990 - November 30, 1995. End of World War II Commemoration This Month’s Featured Exhibit Mr. Frank Riesinger, a retired Tulsa businessman and World War II veteran, organized a 75th commemoration of the end of World War II at Broken Arrow’s Performing Arts Center on the evening of July 14. That is the day in 1945 on which President Truman announced the Japanese government had agreed to accept the Allies’ terms of surrender.