総合解析セミナー

総合解析セミナーは基本的に、毎週木曜日の16:30から行われます。
場所は研究所共同館 3階講義室です。

date	Speaker	title
11/07 Thu	Yoshiki Ito	Computer simulations of pitch angle scattering process for pulsating aurora
Abstract : Whistler mode chorus waves cause scattering and acceleration of energetic electrons in the inner magnetosphere, and recent studies identified that chorus waves cause the pulsating aurora. The interaction processes have been modeled as diffusions in the velocity space, and the scattering rate depends on the wave amplitude. However, the recent studies indicate that the wave-particle interactions with chorus waves are non-linear process, so that it is expected that the scattering rate will not simply depend on the wave amplitude. In this study, we investigate chorus wave amplitude dependence of electron scattering using the GEMSIS-RBW simulation code. The GEMSIS-RBW simulation calculates variations of local pitch angle and energy by the imposed chorus waves. In this simulation, chorus bursts that consist of multi rising tone elements are imposed at the equatorial plane, and these bursts propagate along the field line with L= 4. We calculate the trajectory of a number of electrons with initial energy of 50 keV. At small wave amplitudes, time variations of pitch angle and energy of electrons are similar to diffusive process. At large wave amplitudes, both pitch angle and energy of electrons increase at the interaction with the first rising tone element, and then they decrease at interaction with the second rising tone element. We classify these variations due to wave-particle interaction into three categories; diffusion, phase-trapping and dislocation, by taking into consideration of the parameter ρ. Here, the parameter ρ indicates the ratio of the wave-induced and the background inhomogeneity effects for the momentum change of the resonant electron. When ρ<< 1, variations of pitch angle and the energy of electrons are diffusive. When ρ~1, both pitch angle and the energy of electrons increase because of the phase trapping. When ρ>> 1, both pitch angle and the energy of electrons decrease because of the dislocation. In the simulation, energy and pitch angles of some electrons with ρ~1 increase due to the phase-trapping, which cause increase of ρ. During the second interaction, energy and pitch angles with large ρ decreases due to dislocation, in which ρ also decreases. During the third interactions, energy and pitch angles increase again due to the phase trapping. Therefore, variations of dislocation and phase trapping occur alternately due to variations of ρ. We also calculated the number of precipitating electrons with various wave amplitudes. The number of precipitating electrons increase if the wave amplitude increases from 10 pT to 200 pT. However, as the wave amplitude increases more than 200 pT, the number of precipitating electrons decreases. From this simulation, the simple relationship between the wave amplitudes and precipitating flux is not always satisfied due to the non-linear wave particle interactions, and the depression of the precipitating flux is expected with the wave amplitude of more than a few hundred pT.
10/31 Thu	Ryosuke Fujii	Statistical analysis for trunk structure of ring current ions using Arase ion observations
Abstract : The distribution of ring current ions is determined due to transportation, acceleration and loss process in the magnetosphere. Various structures on energy spectrum are seen along the satellite orbit. Besides well-known structures such as “nose” or “wedge” structures, “trunk” structures are newly found by Van Allen Probes. The structure looks like elephant trunk and the energy of peak flux decreases toward the Earth. A case study by Van Allen Probes showed that “trunk” structures are seen in energy spectrums of helium and oxygen. However, detail characteristics of “trunk” have not been well understood, and statistical survey using the long-term observation data is necessary. In this study, we investigate characteristics of “trunk” using Low-energy particle experiments-ion mass analyzer (LEPi) / Medium-energy particle experiments-ion mass analyzer (MEP-i) onboard the Arase satellite from April 2017 to March 2019. A number of trunk structures in helium and oxygen ions as well as protons are identified. We analyze the geomagnetic activity, local time, latitude and L-value dependences of the trunk. The minimum L-shell of trunk is distributed mostly around L = 2.0 – 2.5 and off-equator, extending from dusk region to pre-midnight region. Previous study suggested that impulsive enhanced electric field or a temporal gap of injection from the tail region combined with charge exchange causes formation of the “trunk”. Beside “trunk” structures, more typical "nose" events and “inverse trunk” in which the typical energy gets increase in the lower L-shell are also found from the Arase observations. We show statistical characteristics of “trunk" and “inverse trunk” from the Arase observations.
10/17 Thu	Toshiki Kawai	Analysis of Small-scale Flares using Genetic Algorithm
Abstract : Coronal heating is one of the long-standing problems in solar physics. So far, two primary mechanisms have been proposed to explain how the corona is heated, namely small-scale magnetic reconnection and wave dissipation. To estimate the contribution of small-scale magnetic reconnection, so called nano-flares, to heat the corona is crucial to solve the coronal heating problem. The purpose of this study is to develop a method which can accurately detect nano-flares and estimate their energies. To reach this goal, firstly, we obtain the light curve of the coronal loop from SDO/AIA 171 observation. Then, we randomly make some “genes” which have the information of flares such as energies and occurrence times. We calculate the pseudo-light curves of SDO/AIA 171 by using one-dimensional hydrodynamic simulations and the response function. The simulation calculates the temporal evolution of a coronal loop heated by flares using genes’ information as inputs. Comparing observed and calculated light curves, the genes are optimized based on the genetic algorithm. Repeating the calculation of pseudo-light curves and optimization of the genes hundreds of times, finally we succeeded in estimating the energies and occurrence times of small-scale flares which occur at the observed coronal loop.
10/10 Thu	Hiroki Ito	Flux decrease of outer radiation belt electrons associated with solar wind pressure pulse: A Code coupling simulation of GEMSIS-RB and GEMSIS-GM
Abstract : Relativistic electron flux of the outer radiation belt dynamically changes in response to solar wind variations. Variations of solar wind cause the flux drop-out of the outer belt electrons. Magnetopause shadowing (MPS) has been proposed to cause rapid loss of relativistic electrons of the outer belt (e.g., Kim et al.,2008). In general, it has been expected that MPS is a cross-field transportation due to convection and/or the dayside compression of the magnetosphere. However, the gyro-radius of relativistic electrons of the outer belt seems to be too small compared with the spatial scale of gradient of the dayside magnetopause to escape across the magnetopause. In this study, we investigate another escaping process of relativistic electrons into the interplanetary space. We conduct a code-coupling simulation of a test-particle simulation code (GEMSIS-RB: Saito et al., 2010) and a global MHD magnetosphere simulation code (GEMSIS-GM: Matsumoto et al., 2010). We calculate a number of trajectories of guiding-center of electrons in electromagnetic fields calculated from GEMSIS-GM. In the simulation, electrons are initially distributed from Re = 6 to 11 with initial energies from 1 MeV to 10 MeV. Initial pitch angles of electrons are distributed from 50 degrees and 90 degrees. In this simulation, the solar wind dynamic pressure and the magnetopause stand-off distance change as follows; [i] The stand-off distance of the magnetopause is 12 R_E with the initial dynamic pressure of 1.0 nPa, B_(y_IMF) of 0.005 nT, B_(z_IMF) = 3.0 nT. [ii] The solar wind dynamic pressure increases to 2.5 nPa, and the magnetopause moves to 9 R_E . In this period, the pitch angle scattering of electrons with L value larger than 9.0 occurs by Drift Shell Bifurcation (DSB). [iii] The dynamic pressure decreases, and the inflation of the magnetopause takes place. The stand-off distance of the magnetopause moves back to 10 "R" _"E" . In this period, electrons with L value larger than 9.25 are scattered by DSB. During phase [ii], the high-latitude magnetic reconnections occur at dawn-side. Several electrons are scattered by DSB and the mirror points change to the high latitude where electrons can escape into the interplanetary magnetic field along the field line. During the periods, the high-latitude reconnections occur at the high-latitude in the dusk side. In phase [iii], the trapped electrons in the magnetosphere escape from the field lines that connect to the interplanetary magnetic field in both the dawn and dusk sides. The flux decreases are found in not only higher-L shell but also the lower L-shell, because ExB drift by the induced dawn-to-dusk electric fields cause the outward movement of relativistic electrons. As a result, some electrons move from closed magnetic field to open magnetic field, which cause the loss of trapped electrons in the lower L-shells at least L = 8.75 during the inflation of the magnetosphere. In our study, it is found that outward transport tends to occur at high energy, because electrons with large drift velocity observes dawn to dusk electric field for large periods. The study reveals some electrons at outer radiation belt escape to high latitude into the interplanetary magnetic field along the field line, which are different process from the traditional MPS.
10/3 Thu	Yusaku Watanabe	Estimation of temporal evolution of coronal hole by surface flux transport model and potential field source surface extrapolation method
Abstract : In this study, we will estimate the temporal evolution of coronal holes by the surface flux transport (SFT) model and the potential field source surface (PFSS) extrapolation method. Estimating the temporal evolution of coronal hole, especially low latitude coronal hole, is crucial for space weather study. So far, we have developed the SFT model calculation to predict the next solar cycle activity and construct the forecast scheme. The possible relationship between the polar magnetic fields in the solar minimum and the solar activity in the maximum of the next cycle has been intensively discussed. Iijima et al. (2017) calculated the polar magnetic field at the solar minimum with the SFT model and concluded that the polar magnetic field of the next cycle is weaker than the current solar cycle. This is because polar magnetic fields are well reproduced by the SFT model. On the other hand, it is not clear whether the middle latitude magnetic fields can be well reproduced or not by the SFT model calculation. The middle latitude magnetic fields estimation is crucial for estimating the temporal evolution of coronal hole. With regard to the September 2017 X9.3 flared active region (NOAA12673), we focused on the transport of the magnetic field and the associated time evolutions in the polar coronal holes and open field lines. We compare the temporal evolution of the solar surface magnetic field by the SFT model calculations and observations. Further, we also calculated a three-dimensional coronal magnetic field using the PFSS extrapolation method with the calculated surface magnetic field distribution as a boundary condition and traced the open magnetic field lines derived from the foot point of the coronal hole. Although with the case where coronal holes are generated for the active region that appeared behind the Sun, we estimated whether we can predict coronal holes by comparing the coronal hole temporal evolution estimated by the SFT/PFSS model and AIA observation.
9/26 Thu	Kento Nakatani	Magnetic field model of solar active regions based on the linear force-free field
Abstract : The prediction of solar flares is an important issue for space weather forecasting. Although solar flares are believed to be caused by the magnetohydrodynamic (MHD) instability in solar active regions, the method for accurately evaluating the stability of solar magnetic field is not yet established. Recently, Ishiguro & Kusano (2017) proposed that a new instability called the Double Arc Instability (DAI) plays a role of an initial driver of solar flares and the critical parameter for this instability can be used to evaluate the stability of active regions [1]. The parameter can be derived by the integration of the magnetic twist as the function of magnetic flux. In order to calculate the magnetic twist, the three-dimensional (3D) magnetic field in the solar corona is needed. The nonlinear force-free field (NLFFF) extrapolation using the photospheric vector magnetic field data is a possible model for the 3D magnetic field [2]. However, the NLFFF extrapolation demands heavy computation and it sometimes cannot well work as a model of solar coronal magnetic field because the force-free condition does not fit to the photosphere. Therefore, in order to improve the efficiency and applicability of the flare prediction using , it may be required to develop a method to approximately but much quickly capture the overall features of magnetic field in solar active regions, especially in the flare triggering region. From this point of view, we try to develop a method to extract the characteristic feature of magnetic field in solar active regions using the linear force-free field (LFFF) model. For this objective, we compare the several methods to optimize the LFFF model as the model of using the data for the solar active region NOAA 11429. [1] Ishiguro, N., &kusano, K.2017, Apj, 843, 101. [2] Muhamad, J., Kusano, K., Inoue, S.,et al. 2017, Apj, 842, 86.
7/25 Thu	Tomoaki Hori	Storm-time meso-scale ionospheric flow fluctuations and its magnetospheric source as seen by SuperDARN-RBSPs-Arase conjunction
Abstract : Recent Super Dual Auroral Radar Network (SuperDARN) observations indicated that ionospheric flow fluctuations of the mHz or lower frequency range appear in the subauroral to mid-latitude region (L ~ 4-6) in association with substorm expansion during magnetic storms. Their azimuthal phase speed as well as the association with substorm injection and/or expansion suggests that the propagating ionospheric fluctuations are caused by energetic (~10s of keV) ions or electrons injected during storm. Although several physical processes were proposed as the generation mechanism for the injection-driven ionospheric fluctuations, only few studies have examined its magnetospheric counterpart with actual observations. The purpose of the present study is to examine what is going on in a region of the magnetosphere corresponding to the ionospheric fluctuations. Several events of westward-propagating fluctuations with good conjunction of SuperDARN, Van Allen Probes, and the Arase satellite observations are analyzed to identify the magnetospheric counterpart of the ionospheric fluctuations. The result is that injected energetic ion populations are always seen in the region which is mapped to the ionospheric fluctuations along the field lines. The ion populations rarely show a bump-on-tail signature in energy spectrum, indicating that drift resonance excited by a bump-on-tail distribution is not a likely cause in these cases. Considering absence of clear, coherent magnetic fluctuations at the satellites, some non-resonant process may play a role in exciting the ionospheric flow fluctuations.
7/18 Thu	KD Leka	Results from the ISEE/CICR Workshop, "Benchmarks for Operational Flare Forecasting" and Future Prospects
Abstract : As the last solar cycle was coming to an end, an opportunity was presented to critically assess the performance of operational flare forecasts, meaning specifically those facilities tasked with providing standardized, daily (or more frequent) forecasts for energetic phenomena on the Sun. In October/November 2017 an ISEE/CICR International Workshop was held examine two questions: (1) "How well do operational flare forecasting methods presently work?" and (2) "What analysis is needed to quantitatively answer that question?" The first two papers resulting from the workshop are now accepted for publication, with contributions from numerous forecasting facilities around the world. I will present the analysis approaches and methodology that were developed by the team for comparing forecast performance results, including the analysis of different method attributes and implementation details, and how they impact performance. The results themselves are not surprising -- many methods demonstrate positive skill but there is no method that performs well by all metrics -- and there are some indications of what approaches provide better performance. I will finally briefly discuss current research directions, and the prospects for improving operational flare forecasting for the next solar cycle.
7/11 Thu	Shinsuke Imada	Thermal Non-equilibrium Plasma Observed by Hinode
Abstract : Plasma in the solar corona is believed to be in thermal equilibrium because of the occurrence of weak Coulomb collisions. To date, many studies have discussed the plasma dynamics in the solar corona assuming thermal equilibrium. Most phenomena observed in the solar corona can be explained under this assumption because the available temporal resolution is not sufficient to resolve non-equilibrium conditions. After Hinode was launched, a very high temporal resolution became available, especially for spectroscopic observation. Now, we can discuss plasma heating or acceleration in the solar corona using extreme-ultraviolet (EUV) spectroscopic observations with high time resolution. Further, we can also observe the solar corona at multiple wavelengths with high spectral resolution. Owing to Hinode observations, we can now discuss plasma dynamics under thermal non-equilibrium conditions, such as non-equilibrium ionization. Recently, thermal non-equilibrium plasma has received attention not only in the field of solar physics but also in other fields such as X-ray astronomy. We also discuss future Japanese satellite mission Solar-C from the thermal non-equilibrium plasma.
7/4 Thu	Jun Chea-woo	EMIC waves in the inner magnetosphere during the Van Allen Probes and ERG era
Abstract : Electromagnetic Ion Cyclotron (EMIC) waves are generated at the magnetic equator at frequencies of 0.2-5 Hz, and these waves are believed to be major loss process of energetic ions and relativistic electrons by pitch-angle scattering. Of fundamental importance for understanding EMIC waves in the inner magnetosphere, we perform the statistical studies of EMIC waves in the inner magnetosphere using the Van Allen Probes and ERG satellites. We showed that different characteristics of EMIC waves under different geomagnetic environments. This result indicated that EMIC waves in the inner magnetosphere are excited by different generation processes. Recently, we investigated long-term EMIC wave distributions near the magnetic equator for 6 years, and found that peak EMIC wave occurrence regions were changed at different observation cycles. Finally, we compared the spatial distributions of EMIC waves observed by the Van Allen Probes and ERG satellite in 2017-2018. From these studies, we discuss the generation and propagation characteristics of EMIC waves in the inner magnetosphere from the magnetic equator to higher magnetic latitudes.
6/27 Thu	Inchun Park	Data calibration of energetic electrons observed by Arase/HEP, and spectrum analysis of magnetic storms
Abstract : The Arase satellite has been observing high-energy radiation-belt electrons since March 2017 with the high-energy electron experiments (HEP) instrument. The observation data has been open to the public from last year. To make reliable data, we calibrated the data using Monte-Carlo particle simulation through Geant4 tool kit. From the simulation, we could calibrate the low energy contamination caused by high-energy electrons using the inverse matrix method. Also, we got precise parameters of the instruments from the research. Through this, we could get the know-how of particle simulation using Geant4. To make easy to applicate other instruments, the simulation tool-kit is developing now. Since the beginning of the observation, the HEP observed more than 33 magnetic storms with Dst values under −30 nT. we investigated the variations of energetic electron flux with a focus on the dropout of the outer radiation belt during the storms. Using the calibrated data, we studied the spectral characteristics of electrons by performing a superposed epoch analysis and found energy dependency of flux dropouts and subsequent recovery of the radiation belt electron. The energy spectrum tends to harden between L ~ 3 to 7 during storm recovery phases. We also examined simultaneous observations of electrons by Van Allen probes to compare them with the Arase data for the same magnetic storm.
6/20 Thu	Yumi Bamba	Study on Precursor Activities Leading to Large Solar Flares
Abstract : The physical properties and their contribution to the onset of a solar flare are still unclear even though small/transient brightening in the chromosphere/corona is considered a precursor phenomenon of a flare. Many studies suggested that photospheric magnetic field changes cause destabilization of large-scale coronal magnetic field structures. We aim to understand how a small photospheric change contributes to a flare and to reveal how the solar atmosphere such as chromosphere and corona behaves in the precursor phase. In this talk, I focus on the sequential X2.2 and X9.3 flares occurred in AR NOAA 12673 in 2017. In this AR, a coronal brightening and corresponding down-flow were observed by spectroscopic instrument EIS onboard the HINODE satellite. I discuss what the coronal brightening and transient down-flow mean in triggering process of the X-flares in the AR NOAA 12673, by comparing with our previous study Bamba et al. 2017b, that reported a chromospheric brightening and corresponding up-flow in a different AR NOAA 12192.
6/13 Thu	Sung-Hong Park	Does hemispheric preference of magnetic helicity sign in solar active regions exist?
Abstract : Over the past decades, there have been extensive observations of various solar features and eruptions in multiwavelength, such as sunspots, filaments, coronal loops, and CMEs. These observations indicate that the Sun preferentially exhibits left-handed, negative-helicity features in its northern hemisphere and their opposite counterparts in the southern hemisphere, independent of the solar cycle. This is called the hemispheric helicity sign preference of the Sun. Uncovering the underlying physical mechanism(s) of this hemispheric preference is essential for a better understanding of the solar dynamo and large-scale flows. In this talk, I will present a statistical study of magnetic helicity in solar active regions in the context of the hemispheric sign preference, in particular, considering separately the two different contributions of magnetic helicity flux through the active region photosphere, i.e., the emergence and shear terms.
6/6 Thu	Satoshi Masuda	Characteristics of big solar flares observed with RHESSI and Nobeyama Radioheliograph
Abstract : During the impulsive phase of a solar flare, a large amount of electrons is accelerated. The most direct diagnostics of electron acceleration are provided through radio and hard X-ray observations where we observe synchrotron emissions in the GHz range and non-thermal bremsstrahlung emissions above typically 10 keV. The best pair to observe these two emissions are the Nobeyama Radioheliograph (NoRH) and the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). We present a statistical study of 35 jointly observed big (>GOES M7-class) flares. Initial results reveal a linear good correlation between the hard X-ray flux above 50 keV and the microwave fluxes at 17 and 34 GHz. This result indicates that the population of accelerated electrons emit both of hard X-rays and microwaves. However, this correlation is surprisingly good, considering the difference of the emission mechanisms. Since gyro-synchrotron emission is very sensitive to magnetic field strength, microwave emission becomes intense if the source is located at a strong magnetic field region like a footpoint region while hard X-ray intensity does not depend on magnetic field strength. Our event list includes two types of flares; one is a flare with a microwave source located around the looptop and the other is a flare with a microwave source at the footpoint or leg region of the flare loop. We investigated the ratio between hard X–ray and microwave peak flux for these two groups. The results showed that there was only a weak dependence between these two groups. To further understand this result, we need event studies with other observations such as Hinode/XRT, SDO/AIA and so on.
5/23 Thu	Akimasa Ieda	Solar flare direct effects on the earth’s E-region ionosphere
Abstract : A short talk by a beginner will address the effects of solar flares directly on the ionosphere. The soft X-ray emission of solar flare immediately enhances the electron density in the lower ionosphere at approximately 100 km altitude. The electron density enhancement at the space station altitude (400 km) is delayed because such electrons come from lower altitudes as the upward ExB drift. Intense flares tend to create intense density enhancements. However, this proportionality is not clear during the initial 20 min. I will discuss a possibility that intense flares may rather choke the upward ExB drift by relaxing the eastward polarization electric field at the earth’s equator.
5/16 Thu	Takafumi Kaneko	Internal velocity field variation of solar prominence as a precursor of plasma eruption
Abstract : Solar prominences are cool dense plasma clouds in the hot tenuous corona. They sometimes erupt and evolve into coronal mass ejections. Predictability of prominence eruptions is of interest in the researches of space weather as well as solar physics. It is known that the interiors of prominences are filled with subsonic turbulent flows. Recent observational studies reported that the standard deviation of the Doppler velocity in the eruptive prominences started to increase several hours before eruptions even when the mean velocity was unchanged. This finding is useful to predict prominence eruptions: however, the origin of velocity field variation in the prominences and the relationship with the magnetically-driven eruptive mechanisms, e.g., magnetohydrodynamic (MHD) instabilities, were unclear. In this study, we performed three-dimensional MHD simulation including gravity, optically thin radiative cooling, and nonlinear anisotropic thermal conduction, and reproduced eruption of a turbulent prominence. In our simulation, the cool dense prominence was formed by radiative condensation (thermal instability), and the prominence erupted after exceeding the critical height of torus instability. Before eruption, the velocity field inside the prominence had complicated distribution containing both upflows and downflows. We confirmed that the vertical flows created the increasing standard deviation which was quantitatively consistent with the observational results. Based on analyses of the simulation result and comparison with observational results, we discuss the relationship between the increasing standard deviation of the vertical flows and the evolution of the coronal magnetic field sustaining prominence.
5/9 Thu	Yoshizumi Miyoshi	New generation process of plasmaspheric EMIC waves in the presence of M/Q=2 ions : Van Allen Probes and Arase observations
Abstract : Electro-Magnetic Ion Cyclotron (EMIC) waves are often observed in the inner magnetosphere. It has been believed that cyclotron resonance with hot ions is a dominant generation process, and the temperature anisotropy is a free-energy to generate waves. The mode conversion from lightning whistler to ion whistler waves is another generation process of EMIC waves. Horne and Miyoshi[2016, GRL] have suggested mode conversion from parallel propagating magnetosonic mode waves (X-mode whistlers) to parallel propagating EMIC waves theoretically, which has not been confirmed by observations. Here, we show new generation process of oblique propagating plasmaspheric EMIC waves through conversion from magnetosonic mode waves from Van Allen Probes and Arase observations. Both satellites identified the significant damping of around the local cyclotron frequency of M/Q=2 (Deutron and/or alpha particles) in the low altitudes. From the analysis of cross-over and cut-off frequencies, we can estimate the ion composition ratio. The maximum composition ratio of M/Q=2 ions is 10% at the altitude around 1000 km. This is newly
4/23 Thu	Lynn Kistler	The Development of the Storm-Time Ring Current, and Its Effects on Wave Generation
Abstract : During geomagnetic storms, the plasma sheet becomes enhanced with O+-rich plasma from the ionosphere. This plasma is then convected into the inner magnetosphere by an enhanced electric field, creating the storm-time ring current. Using a combination of satellites, including Van Allen Probes, Arase, and MMS, we have performed a series of studies that address how the plasma sheet becomes populated, how the transport of this population into the inner magnetosphere can lead to oxygen dominace in the ring current, and what effects the storm-time ring current has on wave generation. We show that both cusp outflow and night-side auroral outflow enter the plasma sheet during the main phase of geomagnetic storms. The relative importance of the sources to the ring current depends on whether they become incorporated into the hot isotropic plasma (>5 keV) that dominates the ring current pressure, and indications are that the cusp source is able to do this more effectively. Using a superposed epoch analysis, we show that the ring current during the main phase is asymmetric, with most of the ions drifting around the dusk side, while the electrons drift around the dawn side. The O+ pressure peaks at lower radial distances than H+ pressure during the main phase, and the O+ pressure can be dominant at lower distances. Finally the enhanced ions drifting duskward during storm leads to EMIC wave generation, while the enhanced electrons drifting eastward lead to chorus wave generation. The resulting waves are important for determining the dynamics of the more energetic electron radiation belts.
4/18 Thu	Kanya Kusano	What is the Integrated Studies of Solar-Terrestrial Environment?
Abstract : The solar-terrestrial environment is a complex system that consists of nonlinear, non-equilibrium, and multi-scale interacting processes. The research in the Integrated Studies Division aims at improving our understanding of the dynamics of various phenomena in the solar-terrestrial environment through data analyses and modeling. The Integrated Studies Division is now playing the leading role for the Project for Solar-Terrestrial Environment Prediction (PSTEP) that is a nation-wide research collaborative project aiming to develop a synergistic interaction between predictive and scientific studies of the solar-terrestrial environment and to establish the basis for next-generation space weather forecasting. In this seminar, I will talk about the overview of the Integrated Studies Division and the PSTEP, and also report about the recent progress of the physics-based prediction of solar flares as an example of the integrated study of the solar-terrestrial environment.