CRs in the heliosphere

Use of AMS-02 and PAMELA experiments data for calibration of NM network and verification of NM yield functions

S. Koldobskiy(1,2), I. Usoskin(2,3), G. Kovaltsov(4), A. Gil(5)
(1) National Research Nuclear University MEPhI, Moscow, Russia
(2) Space Physics and Astronomy Research Unit, University of Oulu, Finland
(3) Sodankyla Geophysical Observatory, University of Oulu, Finland
(4) Ioffe Physical-Technical Institute, St. Petersburg, Russia
(5) Space Research Center, Polish Academy of Sciences, Warsaw, Poland
(6) Institute ofMathematics, Siedlce University, Siedlce, Poland

Launch of PAMELA and AMS-02 experiments started a new era in the study of cosmic rays. One goal of these experiments was to study the cosmic-ray (CR) solar modulation and solar energetic particles phenomena. In particular, the dependence of proton and helium fluxes on solar activity was measured. This allows us to calibrate the neutron monitor response and validate neutron monitor (NM) yield functions (YF). We found that the best agreement between the satellite experiments data and NM data can be obtained using NM YF by Mishev et al. (2013, 2020).
In this work we present the results of the NM YF validation and NM calibration for all active neutron monitors.


Comparison of longterm changes in the flux of cosmic rays according to ground-based detectors, Pamela and AMS-02

Belov A.V., Gushchina R.T., Yanke V.G. Pushkov
Institute of terrestrial magnetism, ionosphere and radio wave propagation (IZMIRAN), Moscow, Russia

Monitoring of cosmic rays on the Earth and near-Earth space by the World Wide Web of detectors gave a series of uniform measurements of the characteristics of galactic cosmic rays from 1957 to the present. These data serve as an experimental basis for obtaining the spectrum of cosmic ray variations outside the magnetosphere retrospectively or in real time using the global survey method (GSM). As a result of the calculations performed during the monitoring period, the magnitude of cosmic ray density variations (zero harmonic) and the spectrum index of variations for the rigidity of 10 GV, which is close to the effective rigidity of particles detected by neutron monitors. Until now, the results of GSM analysis could only be verified by indirect methods. With the advent of measurements of cosmic rays in outer space (in the PAMELA and AMS-2 experiments) up to rigidities of several tens of GV, it became possible to directly verify the application of the GSM technique, the results of which are presented in this paper. The analysis showed good temporal agreement between GSM data and cosmic ray flux measurements with PAMELA and AMS-2 detectors. Ways to increase this accuracy are discussed. A comparison of long-term changes in the flux of cosmic rays according to ground-based detectors and measurements in open space allows us to conclude that they are in good agreement.


Experimental spectrum of cosmic ray variations in the rigidity range 1-20 GV on the Earth orbit by AMS-02 data.

Yanke V.G. Trefilova L.A., Kobelev P. G., Belov A. V., Eroshenko E.A., Gushchina R.T. Pushkov
Institute of terrestrial magnetism, ionosphere and radio wave propagation (IZMIRAN), Moscow, Russia

High-precision data from the AMS-02 orbital cosmic ray detector are important not only for studying dark matter and antimatter, but also provide a unique opportunity for studying particle fluxes with rigidioties up to several tens of GV. In developing methods for reconstructing the parameters of the spectrum of cosmic-ray variations from ground-based data, we used the empirically determined form of the spectrum of cosmic-ray variations: from a simple power law to a multiparameter spectrum.
In the proposed work, in the hardness range to which neutron monitors are most sensitive, a three-parameter spectrum of variations of galactic cosmic rays is obtained from the AMS-02 experimental data. It was found that during the period of negative polarity of the solar magnetic field, a power-law spectrum of variations with strong exponential attenuation in the region of high stiffness is observed. When the polarity changes to positive and at the beginning of the new 24th solar cycle, the spectrum of cosmic ray variations passes into a purely power-law spectrum.


Interplanetary Coronal Mass Ejections as the Driver of Non-recurrent Forbush Decreases

Athanasios Papaioannou, Anatoly Belov, Maria Abunina, Eugenia Eroshenko, Artem Abunin, Anastasios Anastasiadis, Spiros Patsourakos, and Helen Mavromichalaki

Interplanetary coronal mass ejections (ICMEs) are the counterparts of coronal mass ejections (CMEs) that extend in the interplanetary (IP) space and interact with the underlying solar wind (SW). ICMEs and their corresponding shocks can sweep out galactic cosmic rays (GCRs) and thus modulate their intensity, resulting in non-recurrent Forbush decreases (FDs). In this work, we selected all FDs that were associated with a sudden storm commencement (SSC) at Earth, and a solar driver (e.g., CME) was clearly identified as the ICME’s source. We introduce and employ the tH parameter, which is the time delay (in hours) of the maximum strength of the interplanetary magnetic field from the FD onset (as is marked via the SSC), and consequently derive three groups of FD events (i.e., the early, medium, and late ones). For each of these we examine the mean characteristics of the FDs and the associated IP variations per group, as well as the resulting correlations. In addition, we demonstrate the outputs of a superposed epoch analysis, which led to an average time profile of the resulting FDs and the corresponding IP variations, per group. Finally, we interpret our results based on the theoretical expectations for the FD phenomenon. We find that both the shock sheath and the ejecta are necessary for deep GCR depressions and that the FD amplitude (A0) is larger for faster-propagating ICMEs. Additionally, we note the importance of the turbulent shock-sheath region across all groups. Finally, we present empirical relations connecting A0 to SW properties


A new method to model magnetic cloud-driven Forbush decreases

Simone Benella, Monica Laurenza, Rami Vainio, Catia Grimani, Giuseppe Consolini, Qiang Hu, Alexandr Afanasiev

Interplanetary coronal mass ejections (ICMEs) are large-scale solar wind disturbances constituting the counterpart of coronal mass ejections propagating from the Sun and causing galactic-cosmic ray (GCR) intensity depressions known as Forbush decreases (FDs). ICMEs generally contain magnetic clouds (MCs), i.e. coherent plasma structures characterized by a smooth rotation of the magnetic field components, a magnetic field strength higher than the background solar wind and low values of temperature and plasma-beta. A unique and powerful data analysis tool allowing for the study of the quasi-3-D configuration of a MC is the Grad-Shafranov (GS) reconstruction. A suited full-orbit test-particle simulation has been developed to compute the FD amplitude and time profile resulting from the particle propagation through the MC obtained with the GS reconstruction. The equation of charged-particle motion is solved only for protons (90% of the GCR bulk) by assuming an isotropic flux outside the MC region with particle full trajectories integrated in time. The aim of the model application is to investigate the MC effect on GCR propagation and to study the energy dependence of the physical processes involved, providing an estimate of ground-based GCR observations at different latitudes. A comparison between model results and both space- and ground-based cosmic-ray measurements is finally presented and discussed. This work points out the importance of a global knowledge of the large-scale MC configuration in studying the interactions between GCRs and interplanetary structures, suggesting that particle drifts on the MC closed field lines have a primary role in affecting the GCR propagation.


Precursory signals of Forbush Decreases with and without shock wave

Dimitra Lingri, Faculty of Physics, National and Kapodistrian University of Athens, Greece
Helen Mavromichalaki, Faculty of Physics, National and Kapodistrian University of Athens, Greece
Maria Abunina, Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) of the Russian Academy of Sciences, Russia
Anatoly Belov, Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) of the Russian Academy of Sciences, Russia
Eugenia Eroshenko, Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) of the Russian Academy of Sciences, Russia

Many previous studies have proved that before the beginning of a Forbush Decrease (FD) of the cosmic ray intensity, a precursor signal can be observed.
All these surveys were focused on FDs that are associated with a sudden storm commencement (SSC).
In this work we demonstrate that precursors could also be observed in events without a SSC that is determined by an abrupt increase of the interplanetary magnetic field.
The type of precursory signals and their diversity among the events are the main purpose of this study.
We try to figure out similarities and differences on the signals and the associated events from both categories in the last fifty years, from 1969 to 2019, using the same selection criteria of the under investigation FDs. Simultaneously the orientation of the upcoming solar disturbances in comparison to the way they configure the increase of the interplanetary magnetic field and create these signals are discussed.


Interplanetary Coronal Mass Ejection Associated Forbush Decreases in Neutron Monitors

Christopher Light, University of Hawaii at Manoa
Veronica Bindi, University of Hawaii at Manoa
Cristina Consolandi, University of Hawaii at Manoa
Claudio Corti, University of Hawaii at Manoa
Christopher Freeman, University of Hawaii at Manoa
Andrew Kuhlman, University of Hawaii at Manoa
Matteo Palermo, University of Hawaii at Manoa
Siqi Wang, University of Hawaii at Manoa

Interplanetary coronal mass ejections (ICMEs) are eruptions of plasma that propagate outward through the heliosphere. ICMEs, and the shocks they drive, cause a sudden decrease in the cosmic ray flux in the ir local area of the heliosphere, called a Forbush Decrease (FD). A method of defining FDs is established, and an automated process for identifying FDs in neutron monitor data is created. The correlation between ICME properties and Forbush decrease magnitude in 12 different neutron monitors is examined for 91 ICME associated FD events occurring from 2001 through August 2019. A number of ICME properties show positive correlation with FD magnitude, with decreasing correlation strength as neutron monitor cutoff rigidity increases.


Cosmic ray data and Explanation: Energetic and Raw material

Dr. Mohanad Mahdi Salih

About a year and a half after the establishment of a cosmic ray reading station at Tikrit University; This station measures the muon by a specialized device called the muon detector GM-45. Coincidence Through the measurements, three important changes were recorded, which are distinct phenomena:
A- The values ??are more than 10% higher than the average, and this is called an event and it is probably a cosmic space phenomenon associated with extraterrestrial activities.
B - a significant decrease in values ??more than 10% of the average value, a decrease that is accompanied by a decrease in atmospheric pressure from the sensitive device associated with the system. Here it represents the arrival of an atmospheric depression associated with rain or a decrease in temperature
C - a large drop also more than 10%, accompanying the interruption of the Internet from the source.
But on 4/4/2014, what happened is surprising, a sudden decrease of cosmic rays - without atmospheric pressure, which is the usual situation - with a violent storm of and lightning, And the reverse seemed to rise in pressure. It looked up in the pressure. Or sudden change is very fast.
What happened today is very important and confirms that cosmic rays are more important and controlled in the sensitivity of climatic phenomena and in particular important atmospheric declines in cosmic and climatic studies and climate forecasts.


About long term modulation of cosmic rays in the 23-24 solar activity cycles

Yanke V.G., Belov A., Gushchina R.T. Pushkov
Institute of terrestrial magnetism, ionosphere and radio wave propagation (IZMIRAN), Moscow, Russia

Recently, there has been a significant trend in magnetic fields on the Sun. The total magnetic field of the Sun from the end of the 22nd cycle of solar activity (SA) has more than halved and, possibly, this decrease continues.
Changes in the magnetic field are the key to all the active phenomena occurring on the Sun and in the heliosphere and, accordingly, to processes in cosmic rays (CR). In long-term CR variations in 23-24 cycles of SA, the attenuation of the solar magnetic field is displayed, and these variations turned out to be the smallest for the entire time of CR observations on Earth and in near-Earth space.
Model calculations of CR modulation for the two time intervals (21-22 and 23-24 cycles of SA) showed: with a slight difference in the regression characteristics obtained (and the delay time of CR variations relative to the SA indices), the distribution of contributions to the generated CR modulation from the effects of various SA indices is strongly varies in the analyzed periods. Possible reasons for the differences between the last two CA cycles from the previous two are discussed.


Ring of stations method in cosmic rays variations research

M. A. Abunina, A. V. Belov, E. A. Eroshenko, A. A. Abunin, V. G. Yanke, A. A. Melkumyan, N. S. Shlyk, I. I. Pryamushkina

For over 60 years, neutron monitors have been the main standard and high precision detectors for measuring cosmic rays with energy from 400 MeV to hundreds GeV. In order to obtain sufficiently complete information about the distribution of cosmic rays outside the magnetosphere, it is necessary to have a network of detectors spaced evenly enough around the globe. The ring of stations method is one of the most useful methods for studying the properties of the angular distribution of cosmic rays without expressing the cosmic ray intensity in terms of spherical harmonics. The method allows one to get the hourly longitude distribution of the cosmic ray intensity without modeling. The main objective of this work is to expand the use of the ring of stations method, as it is a convenient and useful method of studying cosmic rays variations. Using the ring of stations method, it is possible to study specific angular distributions of the cosmic rays variations that are described poorly by the sum of the first spherical harmonics. The ring of stations method is primarily used to study Forbush decreases. Detailed descriptions of Forbush decreases investigation by the ring of stations method are presented in this study. The application of the method to study the precursors of Forbush decreases and cosmic rays behavior inside the solar wind disturbances is shown.


Dynamics of energetic spectrum of solar-diurnal variations of cosmic rays in 19-24 solar activity cycles

P.Yu. Gololobov, Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy of SB RAS, Yakutsk, Russia
V.G. Grigoryev, Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy of SB RAS, Yakutsk,Russia
G.F. Krymsky, Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy of SB RAS, Yakutsk,Russia
S.K. Gerasimova, Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy of SB RAS, Yakutsk,Russia

Anisotropic angular distribution of cosmic rays in the interplanetary magnetic field reveals itself at the Earth as periodic diurnal variations of intensity. Since energetic sensitivities of the detectors are different then the amplitude and the phase of variations are also differ. This fact provides the possibility to investigate the energy spectrum of the variations when using a sufficient number of detectors. In the current work, the results of the investigation of the energy spectrum of solar-diurnal variations of cosmic rays that are obtained by using the data of neutron monitor and muon telescope networks are presented. The network provides measurements of cosmic rays with median energies from units up to hundreds of GeV. There are presented expected values of amplitude and phase of diurnal variations at the selected ground-based stations for different forms of the energetic spectrum. The calculated data are compared to experimental data during 19-24 solar activity cycles.


Seasonal variation of cosmic ray intensity observed by ground neutron monitor

Suyeon Oh, Department of Earth Science Education, Chonnam National University, Gwangju, Korea Jaesik Jeong, Department of Statistics, Chonnam National University, Gwangju, Korea Jaeyoung Choi, Department of Earth Science Education, Chonnam National University, Gwangju, Korea Yunsu Kang, Department of Earth Science Education, Chonnam National University, Gwangju, Korea

Neutrons and muons as the representative secondary particles are generated by interaction be tween primary cosmic ray particles and air molecules.
They experience the seasonal variation due to the meteorological effect by temperature effect in the previous studies.
The intensity of neutrons has the typical modulation with the various period and reasons such diurnal and solar variation or transient events.
This study shows the preliminary results to examine the specific position where the more cosmic ray particles enter in the orbit of revolution using the daily data at Oulu neutron monitor.
We present the statistical method to eliminate the effect by solar activity across time and to normalize the daily data by different transformations.
Then we report the preliminary results.


Analysis of the rigid spectrums of variations of cosmic rays during Forbush effect on October 8, 2012

Lukovnikova A. A., Institute of Solar-Terrestrial Physics, Russian Academy of Sciences, Siberian Branch Irkutsk, Russia

On October 8, 2012 Forbush effect is studied using ground observations of cosmic rays (CR) on the worldwide network of neutron monitors by the spectrographic global survey. The rigid spectrums of variations of primary CR in Earth's orbit were presented. It is shown indices of CR variation spectra in certain periods of the investigated event.


Wavelet Analysis of Long-Term Variations in NM, Sunspot, and Solar Wind Data

Fraser Baird, University of Surrey
Alexander MacKinnon, University of Glasgow

Wavelet analysis of Moscow NM data shows the well-known roughly 11-year variation in intensity, but with a period lengthening systematically since 1990. However, this varying period is not shown in the wavelet analysis of daily estimated sunspot numbers, a proxy for solar magnetic field strength. This suggests that the source of this variation may not be solar magnetic activity, but rather the changing magnetic field of Earth. To test this hypothesis, we conduct a wavelet analysis of solar wind data, and space-based particle data in search of a variation of cycle period in these data.


Unusual decrease of the cosmic ray intensity in May 2019 on the background of the minima solar activity

Trefilova L.A., Kobelev P.G., Belov A. V., Eroshenko E. A., Yanke V. G. Pushkov
Institute of terrestrial magnetism, ionosphere and radio wave propagation (IZMIRAN), Moscow, Russia

In May 2019, a prolonged decrease in the intensity of cosmic rays to ~ 4% was observed on neutron monitors. Although this is a slight decrease compared with the quasi-eleven-year variation, it stands out well against the background of low solar activity of the 24th cycle.
At this time, according to LASCO / SOHO and STEREO-A data, a series of successive emissions of solar matter was revealed in various UHF bands and on a coronagraph, which influenced the modulation of cosmic rays, creating a series of Forbush decreases that did not have time to recover. The series was associated with two active areas, and began on April 30 with a “reverse halo” CME. This outburst did not reach the Earth, but led to a significant additional modulation of cosmic rays, mostly east of the Earth.
This was followed by a series of smaller eastern emissions on May 1-6, which also did not reach the Earth, but gradually approached it.
The latest releases of the May 8/9 and May 12/13 series created the usual Forbush downgrades. The three-dimensional picture of an unusual decrease in CR is complemented by the observed variations in the Jovian electron flux and the data of the RAD - marsian radiation detector of the Curiosity rover.
In May 2019, cosmic rays once again showed their ability to collect information about remote areas of the heliosphere and transfer it to the Earth. Terrestrial cosmic ray detectors sometimes observe the effects of interplanetary disturbances that have not reached Earth. Eastern emissions are especially effective, blocking the IMF force lines going to the Earth beyond the Earth's orbit and preventing the recovery of cosmic ray intensity.


Recurrence of galactic cosmic rays anisotropy and intensity during solar cycle 24

R. Modzelewska 1, A. Gil 1,2
1. Faculty of Exact and Natural Sciences, Institute of Mathematics, Siedlce University, Konarski Str. 2, 08110 Siedlce, Poland
2. Space Research Centre of Polish Academy of Sciences, Bartycka Str.18A, 00-716Warsaw, Poland

We study the 27-day variations of galactic cosmic ray (GCR) anisotropy and intensity in solar cycle 24 based on neutron monitor (NM) measurements. We compare solar minima: 2007-2009 and 2017-2019 characterized by the opposite polarities of solar magnetic cycle. Now we have an opportunity to re-analyze the polarity dependence of the amplitudes of the recurrent GCR variations in 2007-2008 in A<0 and to compare it with the clear periodic variations related to solar rotation in 2017-2019 in A>0. Since the GCR recurrence is a consequence of solar rotation, we analyze not only GCR fluxes, but also solar and heliospheric parameters examining the relationship between the 27-day GCR variations and heliospheric, as well as, solar wind parameters.


Tracking Cosmic-Ray Spectral Variation during 2007-2018 Using Neutron Monitor Time-delay Measurements

C. Banglieng 1,2, H. Janthaloet 1, D. Ruffolo*,1,2, A. Siz 1, W. Mitthumsiri 1, P. Muangha 1,2, P. Evenson 3, T. Nutaro 4, R. Pyle 5, S. Seunarine 6, J. Madsen 6, P.-S. Mangeard 3, and R. Macatangay 2
1 Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
2 National Astronomical Research Institute of Thailand (NARIT), Chiang Mai 50180, Thailand
3 Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA
4 Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
5 Pyle Consulting Group, Inc., St. Charles, IL 60174, USA
6 Department of Physics, University of Wisconsin, River Falls, WI 54022, USA
* Presenting author

We developed electronics and analysis techniques to indicate variations in the cosmic-ray spectral index using neutron time-delay data from a single station. Here we study solar modulation using neutron time-delay histograms from two high-altitude neutron monitor (NM) stations: (1) the Princess Sirindhorn Neutron Monitor at Doi Inthanon, Thailand, with the world's highest vertical geomagnetic cutoff rigidity, 16.7 GV, from 2007 December to 2018 April; and (2) the South Pole NM, with an atmosphere-limited cutoff of ~1 GV, from 2013 December to 2018 April. From these histograms, we extract the leader fraction L, i.e., inverse neutron multiplicity, as a proxy of a cosmic ray spectral index above the cutoff. After correction for pressure and precipitable water vapor variations, we find that L roughly correlates with the count rate but also exhibits hysteresis, implying a change in spectral shape after a solar magnetic polarity reversal. Spectral variations due to Forbush decreases, 27 day variations, and a ground-level enhancement are also indicated. These methods enhance the high-precision cosmic ray spectral information from the worldwide NM network and extend it to higher rigidity. Partially supported by Thailand Science Research and Innovation award RTA6280002 and US National Science Foundation awards PLR/ATE-1341312, PLR-1245939, PLR-1341562, and their predecessors.


Using Cosmic Rays detected by HST as Geophysical Markers

Gonzalo Tancredi (1), Nathan Miles (2), Susana E. Deustua (2), Germán Schnyder (1), Sergio Nesmachnow (1), Geoffrey Cromwell (3)
(1) Universidad de la República, Montevideo, Uruguay
(2) Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
(3) Scripps Institution of Oceanography, University of California & USGS, San Diego, CA, USA

The Hubble Space Telescope (HST) has been operational for almost 30 years and throughout that time it has been bombarded by high energy charged particles, colloquially referred to as cosmic rays (CRs). HST orbits the Earth at an altitude of ~550km over the surface, with an equatorial inclination of 28.5 deg. We have analyzed images taken by HST from 1995 until present to extract over 1.2 billion CRs. In particular, our analysis is concentrated on 75,908 dark calibration files taken as part of routine calibration programs for five different CCD imagers with operational coverage of Solar Cycle 23 and 24. Most of the dark frames were taken at positions outside the South Atlantic Anomaly. After filtering the data, we observe the expected modulation of galactic cosmic rays by solar activity. Several sporadic events are detected, when the CR flux was over 10 times higher than the mean. We analyze STIS/CCD observations taken as HST crosses over the South Atlantic Anomaly and find a peak cosmic ray flux of ~1100 CR/s/cm2. We find strong evidence for two spatially confined regions over North America and Australia that exhibit increased cosmic ray fluxes at the 5-sigma level. Finally, we correlate the measured CR flux with the data from the NMDB.