Dr
MAHENDRA KUMAR RICHHARIA
(GOVERNMENT MODEL SCIENCE COLLEGE,JABALPUR(M.P.) INDIA 482001)
04/08/2015, 16:00
SH-TH
Poster contribution
The aim of this work is to study the long term variation in third harmonics of cosmic ray intensity on sixty quietest days in a year using the data of high latitude and low latitude neutron monitoring stations during the solar cycle 20-22.It has been observed that in spite of the abrupt change in the amplitude and phase of third harmonic of cosmic ray intensity, the amplitude of third...
Dr
Renata Modzelewska
(Siedlce University)
04/08/2015, 16:00
SH-EX
Poster contribution
The temporal evaluation of the 27-day variation of the three dimensional (3D) galactic cosmic ray (GCR) anisotropy has been studied for 1965-2014. 3D anisotropy vector was obtained based on the neutron monitors and Nagoya muon telescopes data. We analyze the 27-day variation of the (1) two dimensional (2D) GCR anisotropy in the ecliptic plane, and (2) North-South anisotropy (ANS) normal to...
Du Toit Strauss
(North-West University, South Africa)
04/08/2015, 16:00
SH-TH
Poster contribution
The study of the modulation of cosmic rays in the heliosphere has recently been done by using increasingly the stochastic differential equation (SDE) approach to solving the well-known transport equation. This approach, which is now well-established and published, allows for an in depth study of the modulation effects of the wavy heliospheric current sheet (HCS), in particular as its waviness...
PRAVATA MOHANTY
(Tata Institute of Fundamental Research, Mumbai, India)
04/08/2015, 16:00
SH-EX
Poster contribution
A large area (560~m$^2$) tracking muon detector operating in the GRAPES-3
experiment at Ooty in India has been recording cosmic ray muons at a rate of
1.7$\times$ 10$^8$ h$^{-1}$ since 2000. The high statistics data have enabled
sensitive measurement of several solar phenomena to be made including the
solar and sidereal anisotropy and Forbush decreases following coronal mass
ejections....
Mrs
GRACE IHONGO
(UNIVERSITY OF ABERDEEN)
04/08/2015, 16:00
SH-TH
Poster contribution
Galactic cosmic ray flux calculated at 1au within the energy range (0.2-88) Ge V using the model is presented. The relationship between the calculated flux and solar wind is analyzed and presented. Short-time variation of the flux at a fixed energy range is also calculated, and this is used to predict galactic cosmic ray intensity variation at earth.
Omar Musalem
(UNAM)
04/08/2015, 16:00
SH-EX
Poster contribution
We developed a catalog of Forbush decreases (Fd), in the period 2007-2013. To analyze the Fd’s, we used data from three neutron monitors representing low, medium and high cut-off: Oulu (Finland), Moscow (Russia) and Mexico City. We selected the 9 most energetic events in the period to analyze them further. With the available data (interplanetary data from OMNI) we identified that 8 events are...
Yury Balabin
(Polar geophysical institute)
04/08/2015, 16:00
SH-EX
Poster contribution
Analysis of data of world network neutron monitor (NM) has revealed the considerable annual variation of cosmic ray (CR) flux in 2011-2014. The variation observed at all stations: circumpolar, mid-latitude and subequatorial. It is present in the CR density changes obtained by the global survey. Annual variation is observed from 2011 to 2014. Phase variation is the same for all NM with a...
Prof.
Lev Dorman
(IZMIRAN (Russia) and Tel Aviv University (Israel))
04/08/2015, 16:00
SH-TH
Poster contribution
A.V. Belov1, R.T.Gushchina1, L.I.Dorman1,2, V.G.Yanke1
1. IZMIRAN, Kalushskoe ave., 4, Troitsk, Moscow, 142190, Russia
2. Israel Cosmic Ray and Space Weather Center with Emilio Segre’ Observatory on Mt. Hermon, affiliated to Tel Aviv University, Golan Research Institute, and Israel Space Agency
Dorman L. lid010529@gmail.com
Gushchina R. ...
Dr
Roger Ygbuhay
(University of New Mexico)
04/08/2015, 16:00
SH-EX
Poster contribution
At high rigidities (≥ 10 GV) galactic cosmic ray (GCR) particle density gradients and mean free paths (λ) in turbulent interplanetary magnetic field (B) at 1 a.u. can only be computed from the solar diurnal anisotropy (SDA) data. Long-term changes of SDA components recorded by the global network of neutron monitors (NMs) with long track records are used to compute the annual mean values of the...
Dr
Mahendra Kumar Richharia
(Govt. Model Science College, Jabalpur, (M.P.), India)
04/08/2015, 16:00
SH-TH
Poster contribution
The tri-diurnal and quart diurnal anisotropy of cosmic ray intensity have been investigated during the solar cycle 21-22 using the neutron monitor data recorded at different latitudes on sixty geomagnetically quiet days in a year. It has been observed that in spite of the abrupt changes in the amplitude and phase of tri-diurnal and quart diurnal anisotropy in cosmic ray intensity, the phase of...
Agnieszka Gil
(Siedlce University)
04/08/2015, 16:00
SH-EX
Poster contribution
After the reversal of solar polarity in 2014, the Sun is now in the early declining phase of cycle 24. Soon after the polarity reversal, the galactic cosmic ray intensity, as observed, e.g., by neutron monitors at several latitudes (cut-off rigidities) depict an exceptionally large variation at the solar rotation period. This recurrence started in mid-2014 and continues until now (the first...
Michael Alania
(Siedlce University)
04/08/2015, 16:00
SH-EX
Poster contribution
In order to create a two dimensional time dependent relatively realistic model of galactic cosmic ray transport we have found delay time between changes of the galactic cosmic ray (GCR) intensity, on the one hand, and various parameters determined conditions in heliosphere- sunspot numbers SN , magnitude B of the interplanetary magnetic field (IMF), solar wind velocity U, variance of the...
Marek Siluszyk
(Siedlce University)
04/08/2015, 16:00
SH-EX
Poster contribution
Data of Bx, By, Bz components of the Interplanetary Magnetic Field (IMF) have been used to study a features of the IMF turbulences for two positive (A>0) and two negative (A<0) polarity epochs of solar magnetic cycles (1969-2011).
We found that the changes of the exponents vy, νz, νx of the Power Spectral Density (PSD) of the By, Bz, Bx components of the IMF show a radical alternation of the...
Stepan Poluianov
(University of Oulu, Finland)
04/08/2015, 16:00
SH-EX
Poster contribution
The era of direct measurements of solar energetic particle (SEP) fluxes is limited to the last few decades and largely overlaps the Modern grand maximum of solar activity with unusually high solar activity. However, for many purposes it is important to know the fluxes of SEPs on much longer time scale. This can be made only using indirect proxies. Terrestrial proxy archives, such as the...
ARUNBABU Kollamparambil Paul
(Tata Institute of Fundamental Research, Mumbai, India)
04/08/2015, 16:00
SH-EX
Poster contribution
Earth-directed Coronal mass ejections (CMEs) emanating from the Sun and the shock associated with it are the primary drivers of space weather disturbances. Forbush decrease precursors are advance warning of these upcoming magnetic field disturbances. GRAPES-3 tracking muon telescope which is a part of GRAPES-3 experiment located in Ooty, India, provides high statistics measurement of the muon...
Anderson Fauth
(State University of Campinas)
04/08/2015, 16:00
SH-EX
Poster contribution
Muon rate variations during Forbush decreases registered by the Muonca muon detector have been studied. We discuss the Forbush events which occurred on 13 September and 22 December 2014. Since April 2014, muon telescopes located at State University of Campinas, Brazil, inside the South Atlantic Anomaly, has been recording the flux of single muons. The Muonca experiment consists of four modular...
Dr
Ivan Petukhov
(Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy SB RAS)
04/08/2015, 16:00
SH-TH
Poster contribution
Calculation of cosmic ray intensity in a magnetic cloud is realized. It is supposed that the magnetic cloud near the Sun has the shape of a torus segment with typical structure of the magnetic field (magnetic field rope). The magnetic cloud is located in the coronal mass ejection having distribution of movement velocity by radius. The subsequent propagation of ejection in interplanetary space...
Simon Thomas
(University College London)
04/08/2015, 16:00
SH-EX
Poster contribution
Galactic cosmic ray (GCR) flux is modulated by the heliospheric magnetic field (HMF) over decadal time scales, due to long-term, global HMF variations, but also over time scales of a few hours due to structures crossing Earth such as coronal mass ejections or the heliospheric current sheet (HCS). The HCS separates the outward and inward polarities of magnetic field from the Sun and hence is a...
Mikhail Krainev
(Lebedev Physical Institute, Moscow, Russia)
04/08/2015, 16:00
SH-EX
Poster contribution
Recently the maximum phase of the current solar cycle (SC) 24, in many relations anomalous when compared with solar cycles of the second half of the 20-th century, came to the end. The corresponding phase in the GCR intensity cycle is also in progress.
In this paper we study different aspects of the sunspot and GCR behavior around this phase. First, the amplitudes of the SC 24 in the solar...
Sergio Dasso
(IAFE - CONICET - UBA)
04/08/2015, 16:00
SH-EX
Poster contribution
The low energy modes of the Surface Detector array of the Pierre Auger Observatory record variations in the flux of low energy secondary particles with extreme detail. In these modes, the rate of signals above a very low threshold (scalers) and the calibration charge histograms of the individual pulses detected by each water-Cherenkov detector are used. Previous work has studied the flux of...
PRAVATA KUMAR MOHANTY
(Tata Institute of Fundamental Research, Mumbai, India)
04/08/2015, 16:00
SH-EX
Poster contribution
Harmonics in the cosmic ray solar diurnal anisotropy up to third have been
experimentally observed. Very high statistics is required to investigate
higher harmonics because of exceedingly small amplitudes. The GRAPES-3
experiment located in Ooty, India contains a large area (560~m$^2$) tracking
muon telescope that provides a high statistical record of the muon flux
($\sim$4$\times 10^9$...
Rendani Nndanganeni
(North-West University (Potchefstroom campus) South Africa)
04/08/2015, 16:00
SH-TH
Poster contribution
The challenge regarding the modeling of the solar modulation of Jovian electrons lies in determining a reasonable source function which on its part influences the energy range where these particles dominate in the heliosphere. Another controversial issue is what the spectral index of these electrons should be, from the lowest to the highest energies of relevance to solar modulation. If this...
Dr
Serkan Golge
(Space Radiation Analysis Group, NASA Johnson Space Center, Houston, TX, USA)
04/08/2015, 16:00
SH-TH
Poster contribution
The Badhwar-O'Neill (BON) Galactic Cosmic Ray (GCR) flux model is used by NASA to certify microelectronic systems and in the analysis of radiation health risks for human space flight missions. Of special interest to NASA is the kinetic energy region below 4.0 GeV/n due to the fact that exposure from GCR behind shielding (e.g. inside a space vehicle) is heavily influenced by the GCR particles...
Prof.
H.S, Ahluwalia
(University of New Mexico)
04/08/2015, 16:00
SH-EX
Poster contribution
The timeline of solar activity is discussed with data for the annual mean north-south excess (NSE) of hemispheric sunspot numbers (SSNs) for 1945-2014, covering five SSN cycles (18-23) and the rising phase of cycle 24. We report the results of our study of the relation between NSE and galactic cosmic ray (GCR) modulation at 1 a.u. The significance of our results is discussed.
Mikhail Krainev
(Lebedev Physical Institute, Moscow, Russia)
04/08/2015, 16:00
SH-TH
Poster contribution
Quasi-biennial oscillation (QBO) is a well-known quasi-periodical variation with characteristic time 0.5-4 years in different solar, heliospheric and cosmic ray characteristics. Recently it has been shown that there is rather high anticorrelation between the QBOs in GCR intensity near the Earth and in the strength of the heliospheric magnetic field. Besides, it was suggested that both...
David Ruffolo
(Mahidol University)
04/08/2015, 16:00
SH-TH
Poster contribution
Nonlinear guiding center (NLGC) theory has been used to explain the asymptotic perpendicular diffusion coefficient
κ⊥ of energetic charged particles in a turbulent magnetic field, which can be applied to better understand cosmic
ray transport. Here we re-derive NLGC, replacing the assumption of diffusive decorrelation with random ballistic
decorrelation (RBD), which yields an explicit...
ARUNBABU Kollamparambil Paul
(Tata Institute of Fundamental Research, Mumbai, India)
04/08/2015, 16:00
SH-EX
Poster contribution
The relation between the Forbush decreases (FDs) and near-Earth interplanetary magnetic field (IMF) enhancements associated with the solar coronal mass ejections (CMEs) is studied. We have used data from GRAPES-3 tracking muon telescope to identify the Forbush decrease events. We have chosen events that are having a reasonably clean profile, and magnitude $>$ 0.25 %. We have used IMF data from...
Dr
Ivan Gnesi
(Centro "E. Fermi", INFN, University of Turin)
04/08/2015, 16:00
SH-EX
Poster contribution
The monitoring of galactic cosmic ray flux decreases is of interest for the understanding of phenomena that occur on the solar corona, as well as on other observable stars. As it is known, they are related to the emission of mass from the star corona and often related to solar flares, even if such relation is not completely understood.
The effect on the solar wind directly affects the...
Helena Kruger
(North-West University, Potchefstroom)
04/08/2015, 16:00
SH-EX
Poster contribution
The propagation of cosmic rays through the heliosphere is subjected to modulation. This propagation can be described by the Parker Transport Equation. Two simple approximations of this equation are the convection-diffusion and the force-field approaches. The solutions of these equations contain the modulation parameter M and the modulation potential ϕ, respectively. Usoskin et al. (2011) used...
Prof.
Hiroshi Kojima
(Aichi Institute of Technology, Waterloo Road, Aichi, Japan)
04/08/2015, 16:00
SH-EX
Poster contribution
For the investigation of the interactions of galactic cosmic rays with the solar wind plasma and/or interplanetary magnetic field, it is important to know the rigidity dependence of the intensity variations of galactic cosmic rays in detail. In this paper, we have divided the data into two durations of active and calm by a criteria which is based on the data of neutron monitor of the lowest...
Dr
Alisson Dal Lago
(National Institute for Space Research)
04/08/2015, 16:00
SH-EX
Poster contribution
It is well known that cosmic rays with energies below 100 GeV are significantly modulated by solar wind structures populating the heliosphere, which originate at the Sun. We apply a cross wavelet transform and wavelet coherence for examining relationships in time frequency space between isotropic and anisotropic components of cosmic rays data from the Global Muons Detectors Network (GMDN) and...
Agnieszka Gil
(Siedlce University)
04/08/2015, 16:00
SH-TH
Poster contribution
We study temporal changes of a behaviour of the power-law rigidity spectrum of the first three harmonics of the 27-day variation of the galactic cosmic rays (GCR) intensity during the solar cycle (SC) no. 24 and compare with other 11-year cycles of solar activity. We show that our recent finding - a hard spectrum of the amplitudes of the 27-day variation of the GCR intensity in maximum epochs...
Tomasz Seredyn
(Polish Air Force Academy)
04/08/2015, 16:00
SH-EX
Poster contribution
In the paper we statistically inspect Forbush decreases, CMEs, Solar Flares and geomagnetic variations during the solar cycle 24 and compare them with earlier cycles and discuss Sun-Earth system response to extreme solar events and space weather. Data from different spacecrafts, GOES X-ray and LASCO coronograph images were used together with neutron monitor network recordings. The observed...
Dr
Zbigniew Kobylinski
(Polish Air Force Academy)
04/08/2015, 16:00
SH-EX
Poster contribution
Energetic charged particles of galactic cosmic rays (GCR) and in a extent stronger energetic
solar particles penetrate more or less deep into lower atmosphere ionizing the air and affect onto
the value and distribution of electric conductivity, the electric field and other atmospheric electric parameters. The response of the atmospheric electric field (AEF) at ground level to the GCR...
Abdullrahman Maghrabi
(King Abdulaziz City For Science and Technology)
04/08/2015, 16:00
SH-EX
Poster contribution
Forbush decreases are one of the most important cosmic ray time variations observed by ground level monitors and on board space detectors. They mainly occur during the active phases of the solar cycle, and associated with geomagnetic storms caused by solar flares or coronal mass ejections. Experimental studies of Forbush decreases have shown distinct properties. These properties are important...
Mr
Johannes Marquardt
(CAU-Kiel, Germany)
04/08/2015, 16:00
SH-EX
Poster contribution
Helios 1 and 2 were launched in December 1974 and January 1976, respectively. They both explored the inner heliosphere to distances of less than 0.3 AU from the Sun. The University of Kiel experiment on board the solar probe Helios measured high energy charged cosmic ray particles of solar, planetary and galactic origin. The cosmic ray telescope consists out of five semiconductor detectors,...
99.
The effects of particle drifts on the modulation of galactic electrons in the global heliosphere
Rendani Nndanganeni
(North-West University (Potchefstroom campus) South Africa)
04/08/2015, 16:00
SH-TH
Poster contribution
The fundamental process of global curvature, gradient and current sheet drifts in the heliosphere is still not fully understood, especially how solar wind and magnetic field turbulence could affect the magnitude of drifts on a global scale. General consensus is that the so-called weak scattering drifts is giving too large modulation effects as follows from the application of numerical drift...
Stefan Ferreira
(North-West University)
04/08/2015, 16:00
SH-TH
Poster contribution
Proton observations from the PAMELA mission and a comprehensive modulation model, including a new Stochastic Differential Equation (SDE) model, are used to study the details of the modulation of cosmic rays in the inner heliosphere. Recent theoretical advances in determining the diffusion coefficients are used to compute cosmic ray intensities over the unusual last solar minimum activity...
Dr
Marek Siluszyk
(Siedlce University, Poland), Prof.
Michael Alania
(Siedlce University, Poland), Dr
Renata Modzelewska
(Siedlce University, Poland)
04/08/2015, 16:00
SH-EX
Poster contribution
The hourly neutron monitor data have been used to study the role of drift effect in the temporal changes of the diurnal anisotropy. In order to thoroughly separate sectors of the Interplanetary Magnetic Field (IMF) and its influence on the anisotropy of Galactic Cosmic Rays (GCRs) for positive (A>0) and negative (A<0) polarities of solar magnetic cycle, two periods (1995-1997 (A>0) and...
Mitsue Den
(National Institute of Information and Communications Technology)
04/08/2015, 16:00
SH-TH
Poster contribution
Three-dimensional MHD simulation code, REPPU (REProduce Plasma Universe) code, is developed for modeling of space plasma phenomena, and is utilized for the solar surface and the global solar wind structure. The distinguishing features of this code is the 3-D grid system, which has no polar singularity though it is able to fit the spherical structure. This grid system makes it possible to set...
Nicholas Eugene Engelbrecht
(SANSA)
04/08/2015, 16:00
SH-TH
Poster contribution
The stochastic approach to solving the Parker transport equation has relatively recently become a popular means of furthering the numerical study of cosmic ray modulation. This is in part due to the fact that this approach allows for three-dimensional, time-dependent simulations over a range of energies that could not be performed using earlier finite difference techniques. We present here...
Stefan Ferreira
(North-West University)
04/08/2015, 16:00
SH-TH
Poster contribution
The time-dependent modulation of galactic cosmic rays in the heliosphere is studied over different polarity cycles by computing 2.5 GV proton intensities using a two-dimensional, time-dependent modulation model. By incorporating recent theoretical advances in the relevant transport parameters in the model we showed in previous work that this approach gave realistic computed intensities over a...
Michael Alania
(Siedlce University)
04/08/2015, 16:00
SH-TH
Poster contribution
We show that the source of the energy dependence of the rigidity spectrum of the Forbush decrease (Fd) of the galactic cosmic ray (GCR) intensity are the structural changes in the interplanetary magnetic field (IMF) turbulence driven by the shock waves either directely creating near the Sun or shock waves related to the propagation of the CME in interplanetary space. We recognize that during...
Eleanna Asvestari
(University of Oulu)
04/08/2015, 16:00
SH-EX
Poster contribution
Here we present a new semi-empirical model describing modulation of galactic cosmic rays in the heliosphere. The model is an update of the previous similar model by Alanko-Huotari et al. (2006) and considers such heliospheric parameters as open solar magnetic flux, heliospheric current sheet tilt angle and the large scale solar magnetic field polarity. The model has been tested and calibrated...
