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Presentation Mode : All
Conference Day : 02/08/2021
Time Slot : PM1 13:30 - 15:30
Sections : ST - Solar and Terrestrial Sciences










Solar and Terrestrial Sciences | Mon-02 Aug




ST02-A015
A Space Hurricane Over the Earth’s Polar Ionosphere

Qing-He ZHANG1#+, Yongliang ZHANG2, Chi WANG3, Kjellmar OKSAVIK4, Larry LYONS5, Michael LOCKWOOD6, Huigen YANG7, Bin-Bin TANG8, Jøran MOEN9, Zanyang XING1, Yu-Zhang MA10, Xiang-Yu WANG1, Ning-Ya FEI10, Lidong XIA1
1Shandong University, China, 2Johns Hopkins University Applied Physics Laboratory, United States, 3Chinese Academy of Sciences, China, 4University of Bergen, Norway, 5University of California, Los Angeles, United States, 6University of Reading, United Kingdom, 7Polar Research Institute of China, China, 8State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing, China, 9University of Oslo, Norway, 10Shandong University, Weihai, China


In Earth’s low atmosphere, hurricanes are destructive due to their great size, strong spiral winds with shears, and intense rain/precipitation. However, disturbances resembling hurricanes have not been detected in Earth’s upper atmosphere. Here we report a long-lasting space hurricane in the polar ionosphere and magnetosphere during low solar and otherwise low geomagnetic activity. This hurricane shows strong circular horizontal plasma flow with shears, a nearly zero-flow center, and a coincident cyclone-shaped aurora caused by strong electron precipitation associated with intense upward magnetic field-aligned currents. Near the center, precipitating electrons were substantially accelerated to ~10 keV. The hurricane imparted large energy and momentum deposition into the ionosphere despite otherwise extremely quiet conditions. The observations and simulations reveal that the space hurricane is generated by steady high-latitude lobe magnetic reconnection and current continuity during a several hour period of northward interplanetary magnetic field and very low solar wind density and speed.

ST02-A005 | Invited
Multisatellite Observations of Field-aligned Low-energy O+ Ion Flux Enhancements in the Inner Magnetosphere: September 22, 2018, Event

Masahito NOSÉ1#+, Ayako MATSUOKA2, Yoshizumi MIYOSHI1, Kazushi ASAMURA3, Tomoaki HORI1, Mariko TERAMOTO4, Iku SHINOHARA3, Masafumi HIRAHARA1, Craig KLETZING5, Charles SMITH6, Robert MACDOWALL7, Harlan SPENCE6, Geoffrey REEVES8
1Nagoya University, Japan, 2Kyoto University, Japan, 3Japan Aerospace Exploration Agency, Japan, 4Kyushu Institute of Technology, Japan, 5The University of Iowa, United States, 6University of New Hampshire, United States, 7National Aeronautics and Space Administration, Goddard Space Flight Center, United States, 8Los Alamos National Laboratory, United States


Recent studies employing the Arase and Van Allen Probes satellites [Chaston et al., 2015; Kistler et al., 2016; Nosé et al., 2016, 2018; Gkioulidou et al., 2019] have shown that unidirectional/bidirectional energy-dispersed O+ flux appears a few minutes after substorms in the inner magnetosphere and lasts for ~10 min with a decrease in its energy from ~5 keV to 10–100 eV. In the present study, we examine the low-energy O+ ion flux variations simultaneously observed by multiple satellites, Arase, Van Allen Probe A and B satellite, on September 22, 2018. The O+ fluxes are enhanced after a substorm onset at 05:24 UT, at which three satellites are located in the nightside inner magnetosphere (Arase at MLT=0.3 hr, L=6.2, GMLAT=−9.6 deg; Probe A at MLT=0.7 hr, L=5.5, GMLAT=14.7 deg; Probe B at MLT=0.0 hr, L=5.3, GMLAT=10.6 deg). Arase observes O+ flux enhancements only in the parallel direction to the magnetic field in the energy range from a few keV to 200 eV. Probe A and B, however, identify O+ flux enhancements in both parallel and antiparallel directions at 1 keV to 10 eV. The antiparallel fluxes appear earlier than the parallel fluxes. Multiband flux enhancements are detected only by Probe A. We perform numerical calculation of O+ ion trajectories to reproduce the observed E-t spectorgrams at three satellites. In the presentation, we will show results of data analysis and numerical simulation in more detail, and discuss the contribution of the low-energy O+ ion flux enhancements to the O+ content of the inner magnetospheric plasma.

ST02-A023 | Invited
Reporting the Four-wave Interactions Between Whistler Mode Waves

Si LIU#+, Zhonglei GAO
Changsha University of Science and Technology, China


Whistler mode waves play an important role in the radiation belt dynamic. It has been widely accepted that whistler mode waves are generated by the thermal anisotropic energetic electrons. However, nonlinear coupling between coherent waves can also affect the stability of the waves. Here we report the direct evidences of the four-wave interactions between whistler mode waves in the magnetosphere by analyzing the Van Allen Probes data. Injected energetic electrons excite the primary whistler mode waves at frequencies f1 and f2. The secondary waves occur at the frequency f3=f2+f2-f1 with the estimated wave vectors staying in the reasonable range to satisfy the wave-wave interaction conditions. This study suggests that the four-wave interaction can redistribute the wave energy over a broader frequency range and hence potentially affect the magnetospheric electrons over a broader range of pitch angles and energies.

ST02-A004
The Effect of Plasma Boundaries on the Dynamic Evolution of Relativistic Radiation Belt Electrons

Dedong WANG#+, Yuri SHPRITS
GFZ German Research Centre for Geosciences, Germany


Understanding the dynamic evolution of relativistic electrons in the Earth's radiation belts during both storm and nonstorm times is a challenging task. The U.S. National Science Foundation's Geospace Environment Modeling (GEM) focus group “Quantitative Assessment of Radiation Belt Modeling” has selected two storm time and two nonstorm time events that occurred during the second year of the Van Allen Probes mission for in-depth study. In this study, we perform simulations for these GEM challenge events using the 3D Versatile Electron Radiation Belt code.We set up the outer L* boundary using data from the Geostationary Operational Environmental Satellites and validate the simulation results against satellite observations from both the Geostationary Operational Environmental Satellites and Van Allen Probe missions for 0.9-MeV electrons. Our results show that the position of the plasmapause plays a significant role in the dynamic evolution of relativistic electrons. The magnetopause shadowing effect is included by using last closed drift shell, and it is shown to significantly contribute to the dropouts of relativistic electrons at high L*.We perform simulations using four different empirical radial diffusion coefficient models for the GEM challenge events, and the results show that these simulations reproduce the general dynamic evolution of relativistic radiation belt electrons. However, in the events shown here, simulations using the radial diffusion coefficients from Brautigam and Albert (2000) produce the best agreement with satellite observations.



ST12-A001
Sustained Oxygen Spectral Gaps and Their Dynamic Evolution in the Inner Magnetosphere

Chao YUE#+, Xuzhi ZHOU
Peking University, China


Van Allen Probes observations of ion spectra often show a sustained gap within a very narrow energy range throughout the full orbit. To understand their formation mechanism, we statistically investigate the characteristics of the narrow gaps for oxygen ions and find that they are most frequently observed near the noon sector with a peak occurrence rate of over 30%. The magnetic moment (μ) of the oxygen ions in the gap shows a strong dependence on magnetic local time (MLT), with higher and lower μ in the morning and afternoon sectors, respectively. Moreover, we find through superposed epoch analysis that the gap formation also depends on geomagnetic conditions. Those gaps formed at lower magnetic moments (μ < 3000 keV/G) are associated with stable convection electric fields, which enable magnetospheric ions to follow a steady drift pattern that facilitates the gap formation by corotational drift resonance. On the other hand, gaps with higher μ values are statistically preceded by a gradual increase of geomagnetic activity. We suggest that ions within the gap were originally located inside the Alfven layer following closed drift paths, before they were transitioned into open drift paths as the convection electric field was enhanced. The sunward drift of these ions, with very low fluxes, forms a drainage void in the dayside magnetosphere manifested as the sustained gap in the oxygen spectrum. This scenario is supported by particle-tracing simulations, which reproduce most of the observed characteristics and therefore provide new insights into inner magnetospheric dynamics

ST12-A004
Statistical Characteristics of the 39 keV Proton Isotropic Scattering Region (ISR) During Geomagnetic Storms

Long Xing MA+, Yiqun YU#
Beihang University, China


At mid-latitudes, a large number of energetic particles can be deposited on the earth, which not only reflects the configuration of magnetic lines of force but also represents the coupling process between the ionosphere and magnetosphere. In this study, we examine thousands of 39 keV proton isotropic scattering events with Polar Operational Environmental Satellites (POES) observations during 30 storm events in 2013-2018. By analyzing the relationship between the distribution of Isotropic Scattering Region (ISR) and geomagnetic storm intensity and applying the T96 and TS05 magnetospheric models to obtain the global magnetic field configuration, we find the following results: (1) Compared with the distribution of proton ISR in different local times in both hemispheres, it is obvious that the latitude of ISR on nightside is lower than that on the dayside, which may be due to the compression of the magnetic field lines at dayside, leading to the higher latitude of proton ISR at dayside. (2) As the intensity of the geomagnetic storm increases, the area of proton ISR gradually expands, and its lower latitude boundary moves equatorward, which means that the loss cone at lower latitude is more likely to be filled. (3) The distribution of proton ISR in the magnetic equatorial plane is determined by using the T96 and TS05 magnetospheric models, and it is found that the field line curvature (FLC) scattering process plays a dominant role in the formation of the proton ISR. (4) ISR can be used as a standard to test the magnetic field models. It is of great significance to study and analyze the distribution and properties of ISR for constructing the magnetic field configuration and analyzing physical phenomena in the magnetosphere.

ST04-A002
Selective Excitation of Coronal Loop Kink Oscillations Excited by an External Fast Wave

Dae Jung YU#+
Kyung Hee University, Korea, South


Selective excitation of coronal kink oscillations has been considered not possible by an external wave. This cognition is based on the condition of no background shear flow. The shear flow between the external wave source site and the considered coronal loop may affect the wave propagation to the loop and relevant loop oscillations. I study resonant absorption of the cylindrical coronal loop kink oscillations under above conditions. Considering a rectangular function for the shear flow and a linear function for the density in the transitional layer, I solve the ideal MHD wave equation using invariant imbedding method. I find that resonant absorption has different behaviors in two flow regimes which are divided by two critical speeds (V=Vk±VAe) where VAe is the external Alfven speed and Vk is the phase speed of the wave. In the flow regime where flow speed (U) is between Vc- and Vc+, high resonant absorption is obtained when the loop length is long compared to the loop radius, the transitional layer is thin, and the spatial extent of the flow region is relatively small. In the flow regime where U<Vc- and U>Vc+, high resonant absorption is possible when the loop length is relatively small and the transitional layer is thick. In both regions, resonant absorption is sensitively dependent on the small change of the flow speed. As high (low) resonant absorption means high (low) transmission of wave energy into the loop, it is inferred that the shear flow can control the excitation of the coronal loop kink oscillations, causing the selective excitation of the kink oscillations.

ST04-A004
Modelling and Analysis of Wave Modes in Solar Magnetic Flux Tubes with Elliptical Cross-section

Anwar Ali ALDHAFEERI1#+, Gary VERTH2, Wernher BREVIS3, David JESS4, Max MCMURDO2, Viktor FEDUN2
1The University of Sheffield/ King Faisal university, United Kingdom, 2The University of Sheffield, United Kingdom, 3Pontificia Universidad Catolica de Chile, Chile, 4Queen's University Belfast, United Kingdom


Modern ground- and space-based solar observations, e.g., The Daniel K. Inouye Solar Telescope (DKIST), Swedish Solar Telescope (SST), Solar Orbiter, Solar Parker Probe, etc., along with numerical modeling, are an essential tool for our understanding of the physics of the Sun. Here we will discuss the behavior of magnetohydrodynamic (MHD) wave modes that propagate incompressible magnetic flux tubes with an elliptical cross-section embedded in a magnetic environment.  The dispersion relation which describes the behavior of MHD wave modes permitted in an elliptical magnetic flux tube is solved numerically.  Both photospheric and coronal conditions were applied.  We have shown that (i) solutions in the form of even Mathieu functions are more sensitive to the value of eccentricity than solutions with the form of odd Mathieu functions; (ii) if ellipticity of the magnetic flux tube cross-section is increased, a sausage mode can not be easily identified; (iii) even solutions which correspond to the fluting mode can be misinterpreted as a kink mode. In contrast to the fluting modes which are polarized along the major axis and strongly depend on the ellipticity of the magnetic flux tube, the kink and sausage surface modes are practically unaffected by ellipticity.  Several examples of the spatial structure of the eigenmodes permitted in the pores and sunspots will be visualized. The solutions obtained in approximation of cylindrical symmetry are in agreement with previous studies.

ST04-A008
Stability of a Coronal Loop Harbouring a Standing Slow Wave: an Analytical Model in a Compressible Plasma

Michaël GEERAERTS#+, Tom VAN DOORSSELAERE
Katholieke Universiteit Leuven, Belgium


Context: In the context of the solar coronal heating problem, one possible explanation for the high coronal temperature is the release of energy by magnetohydrodynamic (MHD) waves. The energy transfer is believed to be possible, among others, by the development of the Kelvin-Helmholtz instability (KHI) in coronal loops. Aims: Our aim is to determine if standing slow waves in coronal loops can trigger the KHI or other instabilities due to the oscillating shear flow at the loop boundary. Methods: We use linearized non-stationary MHD to work out an analytical model in a cartesian reference frame. The model describes a compressible plasma near a discontinuous interface separating two regions of homogeneous plasma, each harbouring an oscillating velocity field of constant amplitude which is parallel to the background magnetic field and aligned with the interface. The obtained analytical results are then used to determine the stability of said interface. Results: We find that the stability of the interface is determined by a Mathieu equation. In function of the parameters of this equation, the interface can either be stable or unstable. For coronal loop conditions, we found that the interface is stable with respect to the KHI, although it can be unstable with respect to a parametric resonance instability. This entails that, in this simplified setup, a standing slow wave does not trigger the KHI without the involvement of additional physical processes.

ST04-A010
Slow Magnetoacoustic Waves in Gravitationally Stratified Two-fluid Plasmas in Strongly Ionised Limit

Abdulaziz ALHARBI1#+, Istvan BALLAI2, Viktor FEDUN2, Gary VERTH2
1Plasma Dynamics Group, University of Sheffield, United Kingdom, 2The University of Sheffield, United Kingdom


The plasma dynamics at frequencies comparable with collisional frequency between various species has to be described in multifluid framework, where collisional interaction between particles is an important ingredient. In our study, we will assume that charged particles are strongly coupled, meaning that they form a single fluid that interacts with neutrals, therefore we will employ a two-fluid model. Here, we aim to investigate the evolutionary equation of slow sausage waves propagating in a gravitationally stratified flux tube in the two-fluid solar atmosphere in a strongly ionized limit using an initial value analysis. Due to the collisional interaction between massive particles (ions and neutrals), the governing equations are coupled. Solutions are sought in the strongly ionized limit and the density ratio between neutrals and charged particles is a small parameter. This limit is relevant to the upper part of the chromosphere. Our results show that slow sausage waves associated with charged particles propagate such that their possible frequency is affected by a cut-off due to the gravitational stratification. In contrast, for neutral acoustic waves the cut-off value applies on their wavelength and only small wavelength waves are able to propagate. Slow modes associated with neutrals are driven by the collisional coupling with ions.

ST09-A006
X-ray Diagnostic of Stellar Magnetic Field Strength Using Magnetic-field-induced Transitions in Ne-like Ions

Wenxian LI#+
Chinese Academy of Sciences, China


Magnetic fields play a crucial role at many stages of stellar formation and evolution and are the origin of stellar activity. However, magnetic fields are challenging to detect and model directly. The use of the magnetic-field-induced transition (MIT) in Fe X for the measurement of the magnetic field strength in the solar corona has been discussed and demonstrated in a number of recent studies. In this work, we suggest a use of X-ray MIT 2p53s 3P0  - 2p6 1S0 in Ne-like ions for the measurement of stellar magnetic field strength of the order of 1 - 10 kG. We use the ChiantiPy for the spectral modelling and predict the conditions of magnetic fields and densities for each element under which the method can be applied.

ST09-A007
Infrared Diagnostics of the Solar Magnetic Field with Mg I 12 um Lines: Forward-model Results

Xianyong BAI1#+, Han UITENBROEK2, Xin LI3, Yuanyong DENG1, Yongliang SONG3, Yang XIAO3
1Chinese Academy of Sciences, China, 2National Solar Observatory, United States, 3National Astronomical Observatories, Chinese Academy of Sciences, China


The Mg I 12.32 and 12.22 μm lines are a pair of emission lines that present a great advantage for accurate solar magnetic field measurement. They potentially contribute to the diagnosis of solar atmospheric parameters through their high magnetic sensitivity. We calculated the Stokes profiles and response functions of the two Mg I 12 μm lines based on one-dimensional solar atmospheric models using the Rybicki-Hummer (RH) radiative transfer code. The integration of these profiles with respect to the wavelength was used to generate calibration curves related to the longitudinal and transverse fields. The traditional single-wavelength calibration curve based on the weak-field approximation was also tested to determine if it is suitable for the infrared. The 12.32 μm line is more suitable for a magnetic field diagnosis because its relative emission intensity and polarization signal are stronger than that of the 12.22 μm line. The result from the response functions illustrates that the derived magnetic field and velocity with 12.32 μm line mainly originate from the height of 450 km, while that for the temperature is about 490 km. The calibration curves obtained by the wavelength-integrated method show a nonlinear distribution. For the Mg I 12.32 μm line, the longitudinal (transverse) field can be effectively inferred from Stokes V/I (Q/I and U/I) in the linear range below ∼600 G (∼3000 G) in quiet regions and below ∼400 G (∼1200 G) in penumbrae. Within the given linear range, the method is a supplement to the magnetic field calibration when the Zeeman components are incompletely split.

ST09-A009
Diagnosing the Magnetic Field Structure of a Coronal Cavity Observed During the 2017 Total Solar Eclipse

Yajie CHEN1#+, Hui TIAN2, Yingna SU3, Zhongquan QU4, Linhua DENG5, Patricia JIBBEN6, Zihao YANG2, Jingwen ZHANG2, Tanmoy SAMANTA2, Yu LIANG4, Yue ZHONG4
1Max Planck Institute for Solar System Research, Germany, 2Peking University, China, 3Purple Mountain Observatory, Chinese Academy of Sciences, China, 4Yunnan Observatories, Chinese Academy of Sciences, China, 5Chinese Academy of Sciences, China, 6Harvard-Smithsonian Center for Astrophysics, United States


We present an investigation of a coronal cavity observed above the western limb in the coronal red line Fe X 6374 Å using a telescope of Peking University and in the green line Fe XIV 5303 Å using a telescope of Yunnan Observatories, Chinese Academy of Sciences, during the total solar eclipse on 2017 August 21. A series of magnetic field models is constructed based on the magnetograms taken by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory (SDO) one week before the eclipse. The model field lines are then compared with coronal structures seen in images taken by the Atmospheric Imaging Assembly on board SDO and in our coronal red line images. The best-fit model consists of a flux rope with a twist angle of 3.1π, which is consistent with the most probable value of the total twist angle of interplanetary flux ropes observed at 1 au. Linear polarization of the Fe XIII 10747 Å line calculated from this model shows a “lagomorphic” signature that is also observed by the Coronal Multichannel Polarimeter of the High Altitude Observatory. We also find a ring-shaped structure in the line-of-sight velocity of Fe XIII 10747 Å, which implies hot plasma flows along a helical magnetic field structure, in the cavity. These results suggest that the magnetic structure of the cavity is a highly twisted flux rope, which may erupt eventually. The temperature structure of the cavity has also been investigated using the intensity ratio of Fe XIII 10747 Å and Fe X 6374 Å.

ST09-A016
Microwave Spectroscopic Imaging of the Decay Phase of the M4.4 Flare on 2020 Nov 29

Sijie YU1#+, Bin CHEN1, Dale GARY1, Katharine K. REEVES2
1New Jersey Institute of Technology, United States, 2Harvard-Smithsonian Center for Astrophysics, United States


We present microwave imaging spectroscopic observation of the decay phase of the M4.4 flare on 2020 November 29 recorded by the Expanded Owens Valley Solar Array (EOVSA) at 1-18 GHz. During this period the flare, as imaged from a face-on perspective by SDO/AIA and Hinode/XRT in EUV and soft X-ray, develops a plasma sheet extending from the top of the post-flare arcades to ~100” above the looptop region. EOVSA spectroscopic imaging shows two microwave sources: one appears to follow the EUV post-flare arcades, which is consistent with the classic picture of nonthermal electrons gyrating in newly-reconnected arcades; the other one, mostly seen at low frequencies, resides co-spatially with the extended current sheet structure. We investigate the physical properties of the microwave sources including the magnetic field strength and the distribution of nonthermal electrons by combining the concurrent microwave, EUV, and X-ray data, and discuss implications for energy release and particle acceleration during the flare decay phase.

ST09-A018
Systematic Study of Magnetic Field Induced Transition in Neon-like Ions for Measurement of Magnetic Field in Astral Plasma

Yang YANG1#+, Hui TIAN2, Xianyong BAI3
1Fudan University, China, 2Peking University, China, 3Chinese Academy of Sciences, China


In an external magnetic field, adjacent energy levels with the same magnetic quantum number will mix and produce some new transition channel, namely magnetic field induced transition. Measurements to these new transitions, whose intensities are proportional to the square of the external magnetic field, will make it possible to figure out the external magnetic field strength. However, in order to apply this method to measure the magnetic field of astral plasma, it is necessary to calibrate the relationship between the magnetic field intensity and the actual spectral line intensity. In this work, we have systematically studied such transitions from ions of neon-like iso-electronic system, especially neon-like argon, and obtained the relationship between the intensity of magnetic field induced transition and the external magnetic field strength, with various plasma environment parameters. These important theoretical data will provide a possible new theoretical and methodological basis for the magnetic field detection of astral plasma.

ST05-A004
A Scheme for Forecasting Severe Space Weather

Balan NANAN#+
Shandong University, China


We have developed and tested a scheme for forecasting severe space weather (SvSW) that caused all known electric power outages and telecommunication system failures since 1957 and the Carrington event of 1859. The SvSW events of 04 August 1972 has puzzled the scientific community as it occurred during a moderate storm (DstMin = -124 nT) while all other SvSW events occurred during super storms (DstMin ≤ -250 nT). The solar wind velocity V and IMF Bz measured by ACE satellite at the L1 point since 1998 are used. For the earlier SvSW events such as the Carrington event of 1859, Quebec event of 1989, and the events in February 1958 and August 1972 we used the information from the literature. The coincidence of high ICME front (or shock) velocity ΔV (sudden increase in V over the background by over 275 km/s) and sufficiently large Bz southward at the time of the ΔV increase is associated with SvSW; and their product (ΔV×Bz) is found to exhibit a large negative spike at the speed increase. Such a product (ΔV×Bz) exceeding a threshold seems suitable for forecasting SvSW, with a maximum forecasting time of 35 minutes using ACE data. However, the coincidence of high V (not containing ΔV) and large Bz southward does not correspond to SvSW, indicating the importance of the impulsive action of high ΔV and large Bz southward coming through when they coincide. The need for the coincidence is verified using the CRCM.

ST05-A006
Association Between Geomagnetic Storms and Solar Storms in Solar Cycles 23 and 24

Manu VARGHESE#+, Balan NANAN, Qing-He ZHANG, Zanyang XING
Shandong University, China


The solar cycle 24 (2009-2020) has been a weak solar cycle compared to previous solar cycle 23 (1996-2009) with maximum monthly F10.7 being ~160 and ~240, respectively. We investigate the association between the geomagnetic storms and solar storms in the two solar cycles. The solar wind velocity (V) and IMF data from ACE (advanced composition explorer) satellite and geomagnetic activity (Dst, SymH, Kp and AE) data from Kyoto WDC are used for the investigation. The number (N) of the geomagnetic storms (DstMin ≤-50 nT), their total intensity (NxDstMin), and their total impulsive strength (NxIpsDst) in the weak solar cycle 24 are reduced by about 80% each compared to the previous strong solar cycle 23. However, the total speed (NxV) and total value of IMF Bz (NxBz) southward at the ICME front in solar cycle 24 are reduced by only about 20% compared to solar cycle 23. This seems to indicate that the ionosphere-ring current coupling in solar cycle 24 might have reduced much more than the reduction in the solar wind-ring current coupling.

ST06-A003
Detection and Identification of Non-periodic Variations of Cosmic Rays Based on Packet Decomposition and Deep Learning

Bogdana MANDRIKOVA1#, Alexei DMITRIEV2+, Oksana MANDRIKOVA1
1Far Eastern Branch of Russian Academy of Sciences, Russian Federation, 2Moscow State University, Russian Federation


Solar, galactic and magnetospheric energetic particles can cause serious radiation damage for human and equipment during air flights and space missions. Anomalous changes in the dynamics of cosmic rays occur during periods of nonstationary solar phenomena and heliospheric disturbances. At the moment, the problem of identifying and forecasting the anomalies is open. The report presents an automated method for detecting and identifying non-periodic variations in time series of cosmic ray intensity. The method is based on a combination of nonlinear adaptive schemes and deep learning. The Autoencoder paradigm and orthogonal package decompositions are used. The effectiveness of the method is confirmed by numerical calculations using data from a network of ground based neutron monitors.