PEM04-P01

Japan Geoscience Union Meeting 2016

A critical review on solar cycle variation of interplanetary magnetic flux ropes*Katsuhide Marubashi1
1.Asia Space Environment Research Consortium
The interplanetary magnetic flux rope (IFR) has been a subject of extensive research activity since
its discovery in 1981 as a key structure in the solar wind that provide important information on
the solar eruption phenomena and on how the southward magnetic fields are carried from the Sun to
the Earth. In this review, we discuss solar-cycle variation of occurrence frequency of IFRs thatstill remains unsettled, based on our own results. First, we have found more than 500 IFRs in thetime period from 1995 to 2009, whereas the survey by Lepping et al. (AnnGeo, 2006) identified 82
IFRs during 1995-2003. The difference mainly comes from the fact that their survey was not
successful in identifying IFRs when the spacecraft passed only near the surface of IFRs. Our result
indicates that the rate of IFR occurrence to the ICMEs should be much higher than those which weresuggested by previous evaluation. Secondly, the following trend is clearly seen: namely, theoccurrence rate of IFRs increases rapidly after the 1996 solar minimum, reaches maximum in 1998,
and then decreases monotonically toward the next solar minimum. This trend seems in concert withthe trend of the magnetic butterfly diagram (Hathaway,
http://solarscience.msfc.nasa.gov/images/magbfly.jpg). The time of rapid increase of IFR ratecoincides with the time when the active regions begin to emerge at mid latitude (Li et al., Solar
Phys., 2011). In addition, Marubashi et al. (Solar Phys. 2015) found that 2/3 of IFRs were erupted
from neutral lines at the Hale boundaries, using another data base. An important implication isthat the IFR occurrence should be closely related with the evolution of large-scale solar magnetic
fields. An interesting question arises also: how the Hale boundaries are preferably selected forany instabilities to occur that lead CMEs. In a more general term, interrelationships among theoccurrence of IFRs, CMEs, flares, and sunspot cycle seem to be an unsettled problem.
Keywords: coronal mass ejection, solar-cycle variation©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P01 -PEM04-P02

Japan Geoscience Union Meeting 2016

Formation of a Quadrupolar Active Region Producing a Magnetic Flux Rope
*Yoshiaki Oi1, Takaaki Yokoyama1, Shin Toriumi2
1.Graduate School of Science, The University of Tokyo, 2.National Astronomical Observatory of Japan
It is suggested that most of the largest flares in the Sun are produced in active regions hostingdelta-sunspots (Sammis et al., 2000). The formation process of delta-sunspots is not clearly
understood but some of them may be formed by the merging of two beta-sunspots, which produces aquadrupolar active region. Toriumi et al. (2014) showed that the quadrupolar active region was
successfully reproduced in their MHD simulation only when the two merging bipoles were magneticallyconnected with each other in the convection zone. Toriumi et al. (2014) aimed at reproducing anactive region similar to an observed one, NOAA AR 11158, which had produced several flares
including one X-class event. However, no flux ropes or eruptions were found in their simulation.
Therefore, in this work, we aim to propose a theoretical model which produces not only thequadrupolar active region but also the magnetic flux rope. As a result of MHD simulation, we
succeeded in reproducing a flux rope above the polarity inversion line as a consequence of an
emergence of a flux tube from the convection zone. Also we found that the flux rope could reach theupper boundary when reconnection-favored coronal magnetic field was introduced above the developing
active region. In this presentation, we will discuss the formation process of the flux rope andphysical conditions for its ascent.
Keywords: Sun, Flares, Sunspots©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P02 -PEM04-P03

Japan Geoscience Union Meeting 2016

Studies on homologous flares at quadrupole magnetic field using force-free field modeling*Yusuke Kawabata1,3, Satoshi Inoue2, Toshifumi Shimizu3,1
1.Earth and Planetary Science, The University of Tokyo, 2.Max-Planck Institute for Solar System
Research, 3.Institute of Space and Astronautical Science, JAXA
Solar flares are known as abrupt energy release events by magnetic reconnection. The standard 2Dmodel of solar flares, which is called CSHKP model, explains large eruptive flares well. We
analyzed three M-class flares occurring on 2 February 2014, which are difficult to understand with
the CSHKP model. Our investigations primarily focused on the 3D coronal magnetic field structures
formed in the flaring region for attempting to understand why three similar flares (labeled flare
1, flare 2, and flare 3, respectively) are successively produced in the region.
Four flare ribbons were observed at the footpoints of three flaring structures by AtmosphericImaging Assembly aboard the Solar Dynamics Observatory. The observed flare ribbons and coronalflaring structures show similarity in the three flares, which are called homologous flares. The
flare ribbons were located in the four magnetic regions (P1, P2, N1, and N2) at the solar surface.
We derived the three dimensional magnetic field configuration using force-free field modeling with

Hinode/Spectropolarimeter data. We used the squashing factor defined by Titov (1999) to identify
the location of quasi-separatrix layers, i.e., QSLs. The magnetic field lines from the force-freefield modeling give fairly good correspondences among many bright flare kernels in the flareribbons, although we still need to improve the modeling fidelity. The magnetic field lines rooted
on the flare ribbons forms the three-dimensional quadrupole magnetic configuration with an X-shape
separatrix structure in the upper atmosphere.
The region of the highest squashing factor is located at the height of 2000~3000km from thephotosphere, suggesting that the magnetic reconnection may take place at the lower atmosphere. The
magnetic flux in the N1 sunspot appears to be highly twisted, because the QSLs structure derived
with the assumption of the potential field is completely different from what obtained with 3D
magnetic field configuration from the NLFFF modeling. The QSLs structure derived with the NLFFF
results for the SP data taken one day before the occurrence of flare 1 is different from thatderived with the data taken one hour before flare 1. This indicates that the QSLs structure wasformed during the day due to the emergence or the transverse photospheric motions of the magnetic
flux in N1. The temporal evolution of magnetic flux suggests that both the existence of emerging
activities and the conversing motions in and around the N1 sunspot region. Focused on homology anddifferences in the flares, although the spatial distribution of the flare ribbons is similar toeach other in the main period of the flares, there is a little difference in the temporal evolutionof X-ray flux. Such a difference might attribute to the difference in triggering the onset of theseflares. Flare 1 occurred after the occurrence of another flare event at the east side of the flare
1 region, while flare 2 occurred after the upward motion of a dark material. This may indicate thatthe magnetic field shows a similar topology, but the trigger mechanism can alter the temporal
behaviors of the energy release.
Keywords: Solar flare, Magnetic reconnection©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P03 -PEM04-P04

Japan Geoscience Union Meeting 2016

Double Arc Instability in the solar corona*Naoyuki Ishiguro1, Kanya Kusano1,2
1.Institute for Space-Earth Environmental Research, Nagoya University, 2.Japan Agency for
Marine-Earth Science and Technology
The stability of flux rope in the solar corona must be related to the occurrence of solar flaresand coronal mass ejections (CMEs), which are primary cause of solar weather disturbance. Torus
Instability (TI) was recently proposed by Kliem & Toeroek (2006) as the cause of solar eruptions.
However, how the instability can be initiated is not yet well understood. On the other hand, one of
the most likely scenario for the process causing unstable flux rope is the tether-cutting
reconnection suggested by Moore et al. (2001). This scenario suggests that magnetic reconnection
between sheared magnetic fields forms a double-arc loop which can erupts. However, the stability of
double-arc loop was not analyzed yet.
The objective of this study is to analyze the stability of double-arc loop theoretically. We model
double-arc electric current loop using two circular tori connected each other, and numericallycalculate the stability of it. As the result, we found that the double-arc current loop can bedestabilized even if the external field is uniform in contrast to the TI. The results indicate thatthe Double-Arc Instability (DAI) is different from the TI. The decay index which is used as acriteria for TI is not applicable to DAI. Furthermore, we found that in order to make the DAI thetwist of magnetic field line must be larger than one-half. We also show that the growth of DAI issimilar to the observation of flux eruption. These results indicate that the DAI caused by thetether cutting reconnection is a possible scenario, which can well explain how solar eruption canbe triggered.
Keywords: Sun, solar flare, instability©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P04 -PEM04-P05

Japan Geoscience Union Meeting 2016

Continued Operation of Nobeyama Radioheliograph by the International Consortium (ICCON)*Satoshi Masuda1, Kiyoto Shibasaki1,2, Nat Gopalswamy3, Yihua Yan4, Kyung-Suk Cho5
1.Institute for Space-Earth Environmental Research, Nagoya University, 2.Solar Physics ResearchInc., 3.Goddard Space Flight Center, NASA, 4.National Astronomical Observatories, Chinese Academyof Sciences, 5.Korea Astronomy and Space Science InstituteNobeyama Radioheliograph (NoRH) is a radio interferometer specially designed to observe the fulldisk of the Sun at 17 and 34 GHz. Eighty-four antennas with a diameter of 80 cm were installed
along a T-shape baseline (North - South: 250 m, East - West: 500 m). The spatial resolution isabout 10 arcseconds and 5 arcseconds in 17 GHz and 34 GHz, respectively. The time resolution of
NoRH is typically 1 second and 0.1 second for the event mode. NoRH continuously observes the fullsun for about eight hours (22:45 - 6:30 UT) every day. The system has been quite stable and NoRH
data are available in the period more than 99 % out of the total possible operational window.
The National Astronomical Observatory of Japan (NAOJ) has successfully operated NoRH during thesetwo decades. From April 2015, the Solar-Terrestrial Environment Laboratory (now the Institute forSpace-Earth Environmental Research), Nagoya University started the operation of NoRH as arepresentative of the International Consortium for the Continued Operation of Nobeyama
Raidoheliograph (ICCON; http://hinode.stelab.nagoya-u.ac.jp/ICCON/ ). The current ICCON
representatives are N. Gopalswamy (NASA), Y. Yan (NAOC), K. S. Cho (KASI), M. Ishii (NICT), K.
Shibasaki (Nagoya University and Solar Physics Laboratory) and S. Masuda (Nagoya University).
In addition to the core members of this consortium, about 30 researchers collaborate the operationof NoRH. Among them, one chief observer is assigned to check the health of the instrument/computers
and to verify the data quality every day. These daily tasks can be done via internet from a remotesite. This system also works very well for the first one year.
NoRH data are automatically transferred from the observational site (Nobeyama) to Solar Data
Analysis System (SDAS; http://hinode.nao.ac.jp/SDAS/index_e.shtml) of NAOJ at Mitaka, and then allof them are automatically mirrored to Hinode Science Center at Nagoya(http://hinode.stelab.nagoya-u.ac.jp/index.shtml.en). Any researcher registered in either system
can access all of the NoRH data. The software for the data analysis is supplied as a part of thesolarsoft (IDL-based software system mainly maintained by Lockheed Martin Solar and Astrophysics
Laboratory) and distributed via internet.
Keywords: Sun, radio©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P05 -PEM04-P06

Japan Geoscience Union Meeting 2016

Calculation of solar rotation rate using the magnetic field observation, and its long-term
variation*Masashi Fujiyama1, Shinsuke Imada1, Shinobu Machida1
1.Institute for Space-Earth Environmental Research
Space environment around Earth have been influenced by solar wind that is plasma which is released
from the Sun. The plasma is explosively released by phenomena such as solar flare and CMD, and thatexerts a huge damage to our planet and artificial satellite. This is called solar storm. In
addition, the entire change in the solar wind is called space weather that has been studied in avariety of fields. There is a study of solar activity mechanism in one of the Solar-Terrestrial
Environment prediction research.
The Sun it is known that the magnitude of the activity varies 11 year cycle. When activity isstrong, it is called the maximum. Opposite, when weak, it is called the minimum. Along with it also
varies the strong of solar wind occur many solar storms during the maximum phases. In addition itis reported that magnitude of the activity is different in every cycle. It is known that there is acorrelation in the intensity of pole magnetic field and the solar activity in the next cycle whensolar minimum period. So, knowing the pole magnetic field of the current minimum period is usefulto predict the next solar cycle.
In this study, determine the parameters from solar magnetic field observation by the solar
observation satellite SDO/HMI. The parameters (such as differential rotation, meridional flow andturbulent diffusion coefficient) are important for surface flux transport model calculations. We
have developed a module that calculates the parameters of the sun from observed data by two
differential ways (Local Correlation Tracking (LCT), Magnetic Element Tracking (MET)), using theactual data analysis. Compare the results to be estimated by LCT and MET, discussing about thedifferences and characteristics obtained two ways. Further, by analyzing the data up to now fromlaunched (about 6 years), we report the results of consideration for long-term variation of thethree physical parameters in the sun.
Keywords: Sun, Magnetic field observation, Rotation rate, Meridional flow

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P06 -PEM04-P07

Japan Geoscience Union Meeting 2016

The role of η-quenching in MHD flux transport dynamo*Chiaki Ichimura1, Takaaki Yokoyama1
1.Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo“Flux-transport dynamo” (FTD), which is one model of the solar dynamos, succeeded to reproduce thebasic solar cycle features. However, most of FTD studies have addressed the time-development of themagnetic field in a purely kinematic regime. In a kinematic regime, the fluid velocity is given
from observation or other theories, so only magnetic induction equation is solved. On the other
hand, in a non-kinematic (or MHD) regime, both of magnetic field and fluid velocity field arecomputed by solving magnetic induction equation and Navier-Stokes equation. So this regime allows
for the feedback of the Lorentz force on fluid velocity field. Rempel (2006) conducted FTD
simulation in a non-kinematic regime and showed FTD model worked successfully even if strong
feedback on fluid velocity existed.
Here we address FTD simulation based on the model of Rempel (2006) and includes “η-quenching”,
which is not considered in Rempel (2006). It is known that the turbulent magnetic diffusivity usedin the solar dynamos is quenched by the existence of strong magnetic fields. This phenomenon iscalled as η-quenching. And η-quenching can be a powerful mechanism for amplifying magnetic fields(Gilman & Rempel, 2005). The following presents the reasons why we include the effect of
η-quenching. One reason is that the maximum magnetic field strength is around 15 kG in Rempel(2006), though rising flux tube simulation (Weber et al., 2011) concluded that magnetic flux tubes
forming sunspots should have field strengths around 40-50 kG. The other reason is that no study has
investigated the role of η-quenching in a non-kinematic FTD model. Stronger magnetic fields
amplified by η-quenching result in stronger feedback to fluid velocity. To investigate this effect,
we need to conduct a non-kinematic dynamo simulation in which both of velocity fields and magnetic
fields are computed.
We find that η-quenching can amplify magnetic fields even in a non-kinematic regime and the
maximum magnetic field strength can be up to around 2 times larger than the case without the effectof η-quenching. However, this amplification leads to the significant feedback to fluid velocity.
This feedback makes the amplitude of temporal variations of the solar rotation rate, which is known
as torsional oscillations, too large to be consistent with observation.

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P07 -PEM04-P08

Japan Geoscience Union Meeting 2016

Reconstruction of high energy particle environment in geostationary orbit based on several
satellite observations*Tsutomu Nagatsuma1, Kaori Sakaguchi1, Yuki Kubo1, Hideki Koshiishi2
1.National Institute of Information and Communications Technology, 2.Japan Aerospace Exploration
AgencyCurrently there are several geostationary satellites which monitor high energy particle
environment, although more than four hundreds of satellite exist in this orbit. New Japanesegeostationary meteorological satellite, Himawari-8, has operated space environment data acquisition
monitor since Nov. 2014. Because the magnetic dipole axis is not aligned with the rotational axisof the Earth, L-value of each GEO satellite is not the same and it changes depending on space
weather conditions. To monitor the current condition of high energy particle environment for eachsatellite in GEO, which is a risk of spacecraft charging, we need to reconstruct high energy
particle environment in GEO using several high energy particle observations. Before combining
individual data from high energy particle sensors, cross calibration of each sensor is essential.
However, the cross calibration needs some technique, because the specification of individual sensor
is not the same. So we need to develop method of cross calibration of the sensor, and of combining
individual particle data for reconstruction. In this presentation, we will introduce crosscalibration method of high energy particle sensor and how to reconstruct high energy particle
environment in geostationary orbits using data from the sensor onboard Himawari-8, GOES-13, 15, andKodama. We also introduce our online database for archiving and providing Himawari-8 high energy
particle data.
Keywords: Space Weather Forecast, Geostationary Orbit, High Energy Particle Observation©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P08 -PEM04-P09

Japan Geoscience Union Meeting 2016

The status of the SEDA-AP/Heavy Ion Telescope*Haruka Ueno1, Haruhisa Matsumoto1, Kiyokazu Koga1
1.Japan Aerospace Exploration Agency
Space radiation such as solar energetic particles (SEP), galactic cosmic rays (GCR) and trapped
particles cause to our space activities. Heavy ions, in particular, have high linear energy
transfer (LET), which exacerbates the risks of radiation exposure for astronauts and errors ofelectric circuits for satellites. The Japan Aerospace Exploration Agency (JAXA) has operated theSpace Environment Data Acquisition Equipment-Attached Payload (SEDA-AP), installed at theInternational Space Station (ISS) Japanese Experiment Module (Kibo) - Exposed Facility, since 2009.
On July 10 2015, JEM-EF was configured with the relocation of the SEDA-AP from no. 9 to no. 11. The
Heavy-Ion Telescope (HIT) is the one of the SEDA-AP instruments, which comprises two
position-sensitive silicon detectors and 16 silicon detectors. Based on the dE×TE
particle-identification method, HIT measures fluxes and energies of energetic ions from Li to Fe
and. The results of HIT are consistent with the general GCR model and other experiment inside theISS in terms of abundances of elements and LET distributions. In addition, HIT has observed heavy
ions from a X5.4 solar flare. We will report the new results of analysis for data from July 2015,
and the changes of the temperature environment and the count rates in order to evaluate the effects
of relocation.
Keywords: ISS, SEDA-AP, heavy ions©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P09 -PEM04-P10

Japan Geoscience Union Meeting 2016

The solar modulation of galactic cosmic rays and radiation dose of aircrews during thesolar cycle 24/25
Shoko Miyake1, *Ryuho Kataoka2, Tatsuhiko Sato3
1.National Institute of Technology, Ibaraki College, 2.National Institute of Polar Research,
3.Japan Atomic Energy Agency
The variation of galactic cosmic rays (GCRs) in the heliosphere is caused by the solar-terrestrial
environmental changes. Owing to this variation known as the solar modulation of GCRs, the counting
rate of the ground-based neutron monitors and a radiation dose of aircrews at the top of thetroposphere also change with the solar-terrestrial environmental changes.
We have developed the time-dependent and three-dimensional model of the solar modulation of GCRs,
based on the stochastic numerical method. Our model can reproduce and predict the intensity of GCRs
in the heliosphere by assuming the variation of the solar wind velocity, the strength of theinterplanetary magnetic field, and its tilt angle. Moreover, we can calculate the neutron monitor
counting rate and the radiation dose of aircrews at an aircraft altitude by using our model coupledwith the results of air-shower simulation performed by PHITS (Particle and Heavy Ion Transport code
System).
In this presentation, we report the results of the solar modulation of GCRs, neutron monitor
counting rate, and the radiation dose at flight altitude from the solar cycle 22/23 until the cycle
24/25. We also discuss about the possibility of increase of the radiation dose of aircraft at thecycle 24/25.
Keywords: galactic cosmic rays, heliosphere, radiation dose, neutron monitor©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P10 -PEM04-P11

Japan Geoscience Union Meeting 2016

The verification experiment for aerosol nucleation focused on a kind of secondary cosmic
rays*Asami Suzuki1, Kimiaki Masuda1, Yoshitaka Itow1, Takashi Sako1, Yutaka Matsumi1, Tomoki Nakayama1,
Sayako Ueda, Kazuhiko Miura2, Kanya Kusano1
1.Institute for Space-Earth Environment Research, Nagoya University, 2.Faculty of Science ,Tokyo
University of Science
It is considered that the solar activity may affect the global climate, but the correlation
mechanism is still not understood. One of the possible mechanisms for the correlation is the cloudformation by the galactic cosmic rays, which are modulated by the variation of solar magnetic
activity. This relation was clearly indicated by the good correlation observed for the galactic
cosmic-ray intensity and the global low-cloud amount. This hypothesis includes the ion-induced
nucleation model, in which new particles in the atmosphere are created efficiently throughatmospheric ions produced by cosmic rays, and finally these particles grow up to the size of cloud
condensation nuclei. In this study, a laboratory experiment for verification of the hypothesis has
been conducted with a reaction chamber. A flow of clean air with water vapor, ozone and sulfuric
dioxide was introduced to a metallic chamber, where we irradiated UV light for solar irradiance andaccelerator beam for cosmic rays. The beam of the heavy ion accelerator HIMAC at National Instituteof Radiological Sciences was used in the present experiment.
In this presentation, I will report the results of the proton and nitrogen ion irradiation
experiments. These high-energy ions have different ionization loss. The ionization loss is an index
representing the ability to ionize the air molecules, that is, a parameter that contributes to theatmospheric ion generation. Furthermore, the simulation shows that the proton and the neutroncontained in the secondary cosmic rays, keep the variation of solar activity even on the groundsurface. Neutrons in secondary cosmic rays may generate energetic heavy ions (nucleus) throughnuclear collisions with atmospheric atoms. Then, these energetic ions produce ionization ionsthrough electronic energy loss process. Since it is considered that the aerosol particle generation
would be increased according to the amount of ions produced in the energy loss, the experiment was
carried out by using these heavy ions.
We will present the experimental result and discuss the difference of aerosol nucleation efficiency
between different kinds of secondary cosmic rays.

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P11 -PEM04-P12

Japan Geoscience Union Meeting 2016

Relationship between solar wind dynamic pressure and amplitude of geomagnetic suddencommencement (SC)*Tohru Araki1, Atsuki Shinbori2
1.Formerly Kyoto Univ., 2.RISH, Kyoto Univ.
Although the primary cause of the geomagnetic sudden commencement (SC) is the enhanced magnetopause
current, induced field aligned currents, ionospheric currents and earth currents produce a complex
global distribution of the amplitude and waveform of SC. As the result the SC amplitude shows aclear latitudinal and local time variation. These variations have not been taken into account in
the Siscoe’s linear relationship ( dH = C* d( Pd**0.5 )) which connects the SC amplitude (dH) withthe corresponding dynamic pressure (Pd) variation of the solar wind.
By considering the physical background of SC we studied which local time is best to extract the
information of the solar wind dynamic pressure and concluded that the SC amplitude at 4-5h local
time of middle- and low-latitude stations most directly reflects the dynamic pressure effect.
This result is used to re-check the order of magnitude of the largest 3 SCs ( dH > 200 nT at
Kakioka) observed since 1868 (Araki, 2015). The SC occurred on March 24, 1940 still keeps the firstrank even if
the LT variation is taken into account.
Keywords: geomagnetic sudden commencement(SC), solar wind dynamic pressure , , ionospheric current,
field aligned current, LT variation, Siscoe’s relationship©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P12 -PEM04-P13

Japan Geoscience Union Meeting 2016

On measurement plan of geomagnetic induced current of power transformers in Japan*Shinichi Watari1, Yusuke Ebihara2, Shigeru Fujita3, Tada-nori Goto4
1.National Institute of Information and Communications Technology, 2.Research Institute for
Sustainable Humanosphere, Kyoto University, 3.Meteorological College, Japan Meteorological Agency,
4.Graduate School of Enginieering, Kyoto University
It has been considered that the effect on power system by geomagnetically induced current (GIC) is
not significant in Japan because of its geomagnetic latitude. However, the damage of the powertransformers was reported in Republic of South Africa located in the same geomagnetic latitude as
the northern part of Japan when a series of geomagnetic storms occurred between in the end of
October and in the beginning of November 2003. It is known that amplitude of GIC depends onunderground conductivity structure. We need to consider the complex underground structure in Japan
when we make a GIC model. We report the measurement plan of GIC for the modeling.
Keywords: geomagnetically induced current, geomagnetic storm, power system©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P13 -PEM04-P14

Japan Geoscience Union Meeting 2016

Three components analysis of ground magnetometer network data toward understanding GIC
excited by space weather disturbances*Shuji Abe1, Hiroki Matsushita2, Yukari Nawata3, Akimasa Yoshikawa4
1.International Center for Space Weather Science and Education, Japan, 2.Department of Earth andPlanetary Sciences, Graduate School of Science, Kyushu University, 3.Department of Earth andPlanetary Sciences, School of Science, Kyushu University, 4.Department of Earth and Planetary
Sciences, Faculty of Science, Kyushu University
The aim of this study is to make hazard maps of induced electric field from geomagnetic
disturbances for estimating possible GIC (Geomagnetically Induced Current) effects from space
weather events in mid- and low- latitude region, including Japan. As a first step, we performed
frequency analyses to three components of 10 ground magnetometers data all over Japan. 5
magnetometers belongs to MAGDAS project managed by International Center for Space Weather Scienceand Education, Kyushu University, 3 magnetometers belongs to Japan Meteorological Agency, and 2
magnetometers belongs to Geospatial Information Authority of Japan. The analysis period is one
month (July, 2012). In this study, we put a focus to not only H- and D-components, reflecting
global space weather disturbances, but also Z-component, reflecting local electromagnetic structurearound an observation point. The analysis methods are as follows: 1) Comparison of similarities
between H- and D-component (global effect) and Z-component (local effect) at each station, 2)Frequency analysis using above data set, 3) Pre-estimation of GIC effect using time derivative
data. As a result, we found that the Z-component shows very complex changes because of thedifference of underground structure at each station. In this presentation, we will introduce
detailed results of our analyses and future plans.
Keywords: GIC, magnetometer network©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P14 -PEM04-P15

Japan Geoscience Union Meeting 2016

Studies of the thermosphere and ionosphere with the EISCAT radar and wholeatmosphere/ionosphere model: GAIA
*Hitoshi Fujiwara1, Yasunobu Miyoshi2, Hidekatsu Jin3, Hiroyuki Shinagawa3, Satonori Nozawa4,
Yasunobu Ogawa5, Ryuho Kataoka5, Huixin Liu2
1.Faculty of Science and Technology, Seikei University, 2.Department of Earth and Planetary
Sciences, Faculty of Sciences, Kyushu University, 3.National Institute of Information andCommunications Technology, 4.Institute for Space-Earth Environment Research, Nagoya University,
5.National Institute of Polar Research
The thermosphere/ionosphere is the region that shows both the features of the atmosphereand space. For example, the behaviors of the neutral and ionized gases characterize
the region through some collision and radiative processes. In addition, interactions between
neutral and ionized gases cause various phenomena in the thermosphere/ionosphere.
The thermosphere/ionosphere is also important for radio wave propagation and operationof artificial satellites due to the atmospheric drag force. The accuracy of navigation systems
and life time of the satellites depend strongly on the thermospheric/ionospheric conditions.
In order to investigate the thermosphere/ionosphere, we have developed a numerical model
which includes all the atmospheric regions and ionosphere named GAIA. GAIA has reproduced
some thermospheric/ionospheric phenomena and revealed physical mechanisms in association withthe phenomena. In this study, we present a brief description of GAIA and show some recent
results. The collaboration with radar observations enables the GAIA simulations to be moreproductive. We will show some European incoherent scatter (EISCAT) radar observations incooperation with GAIA simulations. The future plans of the EISCAT observations and GAIA
simulations will be also shown here.
Keywords: thermosphere, ionosphere, GAIA, EISCAT©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P15 -PEM04-P16

Japan Geoscience Union Meeting 2016

Occurrence probability of plasma bubbles deduced from GAIA simulation data
*Hiroyuki Shinagawa1, Hidekatsu Jin1, Yasunobu Miyoshi2, Hitoshi Fujiwara3, Tatsuhiro Yokoyama1,
Yuichi Otsuka4
1.National Institute of Information and Communications Technology, 2.Kyushu University, 3.Seikei
University, 4.Nagoya University
In the forecast of ionospheric disturbances, it is important to predict mesoscale ionosphericphenomena such as plasma bubbles, sporadic E layers (Es), and Storm Enhanced Density (SED), whichhave significant influences on radio communication and broadcast systems as well as global
positioning systems. Prediction of those phenomena requires real-time observation and ahigh-resolution numerical model of the ionosphere and atmosphere. We have been developing a wholeatmosphere-ionosphere coupled model, GAIA (Ground-to-topside model of Atmosphere and Ionosphere for
Aeronomy), which self-consistently solves the entire region from the lower atmosphere to theionosphere. Although present version of GAIA does not have enough spatial resolution to reproduce
individual plasma bubbles, it is possible to deduce the occurrence probabilities by estimating thelinear growth rate of the ionospheric Rayleigh-Taylor instability in the GAIA simulation data. We
have performed a long-term simulation using GAIA covering a period from 1996 to the present. Using
the database we calculated the linear growth rate, and compared the result with plasma bubble
observations. We found that a period in which large linear growth rates appeared in the simulation
data tends to correspond to a period of plasma bubbles occurrence, suggesting a possibility ofprediction of plasma bubble occurrence using GAIA simulation.
Keywords: plasma bubble, GAIA, linear growth rate, Rayleigh-Taylor instability, ionosphericdisturbance©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P16 -PEM04-P17

Japan Geoscience Union Meeting 2016

The Mid-Latitude Trough and the Plasmapause Detected by DEMETER*ChaoYen Chen1, Jann-Yenq Liu1, I-Tee Lee2
1. National Central University, Taiwan, 2.Central Weather Bureau, Taiwan, R.O.C
This paper finds the mid-latitude trough and the plasmapause by the daytime/nighttime (about
10:00/22:00 LT, local time, respectively) electron density, electron temperature, and whistler of
DEMETER during 2006-2009. The electron density and the electron temperature are useful to allocate
the trough, while the whistler can be used to find the plasmapause. It is found that the trough isvery unclear and complex in the daytime, and however the plasmapause can be detected in both
daytime and nighttime. Therefore, we focus on the relationship of nighttime trough and plasmapause
in various seasons and geomagnetic actives. Results show that the mid-latitude trough tends toappear in the polarward side of the plasmapause, and the trough moves equatorrward during a higher
geomagnetic activity, while the plasmapause is insensitive to the activity.
Keywords: ionosphere, mid-latitude trough, plasmapause©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P17 -PEM04-P18

Japan Geoscience Union Meeting 2016

Latitudinal and Longitudinal Variations of Ionospheric Storms by the Global Ionosphere Mapof Total Electron Content*TsungYu Wu1, Jann-Yenq Liu1
1.National Central University, Taiwan
In this study, we examine latitudinal and longitudinal variations of the total electron content(TEC) during the 2003 Halloween storm. The global ionosphere map (GIM) of TEC retrieved from Center
for Orbit Determination in Europe is used to investigate the positive and negative storm signaturesat various universal times (UT) and global fixed local times (GFLT). The positive and negativestorm signatures are prominent at low and middle latitudes, respectively. The UT results show clear
longitudinal phase shifts in both positive and negative storm signature. The positive (negative)
storm signature reveals the period of 26 (24) hrs and the phase velocity of 14 (15) deg/hr in thelongitudinal direction. On the other hand, the GFLT results show that the positive (negative) storm
signature tend to appear at equatorial-equatorial iononization anomaly (low-middle) latitudes in
daytime. Finally, a statistical analysis of the ionoospheric storm signature is carried out andcross compared with that of the 2003 Halloween storm.

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P18 -PEM04-P19

Japan Geoscience Union Meeting 2016

Ionospheric Data Assimilation Model by Using Radio Occultation and Ground-based GPS
Observations*CHIYEN LIN1, Tomoko Matsuo2,3, Jann-Yenq Liu1, Charles Lin4, Ho-Fang Tsai4
1.Graduate Institute of Space Science, National Central University, TAIWAN, 2.Cooperative Institutefor Research in Environmental Sciences, University of Colorado, USA, 3.Space Weather Prediction
Center, National Oceanic and Atmospheric Administration, USA, 4.Department of Earth Sciences,
National Cheng Kung University, TAIWAN
Ionospheric data assimilation is a powerful approach to reconstruct the three-dimensional
distribution of ionospheric electron density from various types of observations. The ionospheric
data assimilation model based on the Gauss-Markov Kalman filter with the International Reference
Ionosphere as the background model is used to assimilate two different types of total electron
content (TEC) observations from ground-based GPS and space-based FORMOSAT-3/COSMIC (F3/C) radio
occultation (RO). The new satellite mission FORMOSAT-7/COSMIC-2 (F7/C2) will place 12 microsatellites in orbits with two launches in 2016 and 2018, the satellite mission is expected to yield
more than 8,000 RO observation per day. The Observing System Simulation Experiments (OSSEs) of
assimilating FORMOSAT-7/COSMIC-2 (F7/C2) RO and ground-based GPS data in the data assimilation
model are implemented in the study, the OSSEs results demonstrate that the F7/C2 RO data canincrease model accuracy more than assimilating F3/C RO data. The new ionospheric data assimilation
model that employs the location-dependent background model error covariance, Kalman filter forecast
step, and Kalman filter measurement update step could reconstruct the three-dimensional ionosphericelectron density distribution satisfactorily from both ground- and space-based GPS observations.
Keywords: Ionosphere, Data Assimilation, FORMOSAT-3/COSMIC©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P19 -PEM04-P20

Japan Geoscience Union Meeting 2016

Monitoring global ionospheric structures using a near real-time Global Ionospheric Map*Yang-Yi Sun1, Jann-Yenq Liu1, Ho-Fang Tsai2
1.Graduate Institute of Space Science, National Central University, 2.Department of Earth Science,
National Cheng Kung University
To efficiently monitor the fast changing ionospheric weather events, such as magnetic storms, solar
flares, solar eclipses, earthquake precursors, etc., a near real-time (4-hour delay) Taiwan Global
Ionospheric Map (TGIM) is constructed from global vertical total electron content (TEC)
observations using a spherical harmonics expansion. The TEC is measured by about 120 ground-based
GPS stations and FORMOSAT-3/COSMIC. The high correlation (correlation coefficients > 0.95) of the
TGIM and the CODE and JPL GIMs suggests that the TGIM show global scale ionospheric structures aswell as the other two GIMs. The high temporal resolution of the TGIM (5 to 15 minutes) reveals that
it is capable of showing the variation in ionospheric density structures in more detail. Here wealso examine a severe geomagnetic storm, which is the largest during the weak solar cycle 24,
occurred on 17 March 2015 at 0445 UT, using the GIMs. The results show the positive storm is
pronounced at mid- and low-latitudes in the first day after the storm onset. The negative storm
remains present in the equatorial ionization anomaly crest regions more than one week. The suddenchange in TEC at middle and low latitudes during the main phase period maybe associated with theequatorward disturbance wind and the prompt penetration electric field.
Keywords: Ionospheric weather, Global ionospheric map, FORMOSAT-3/COSMIC, GPS TEC©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P20 -PEM04-P21

Japan Geoscience Union Meeting 2016

Operational forecast of foF2 above Tokyo using solar wind input to a neural network*Herbert Akihito Uchida1,4, Wataru Miyake2, Maho Nakamura3, Ryuho Kataoka4,1
1.SOKENDAI (The Graduate University for Advanced Studies), 2.Tokai University, 3.Tokyo Gakugei
University, 4.National Institute of Polar Research
A new empirical prediction model of foF2 above Tokyo, Japan (Uchida et al., 2016, submitted), hasstarted its forecast operation at National Institute of Polar Research. Solar wind parameters areused for the first time to the input of a neural network (NN) to predict foF2 in that study. The
model showed better forecast results compared to an existing operational NN model (Nakamura et al.,2009) which forecasts foF2 using K-index to the input. The results support our expectation that the
NN can represent the physics between the ionospheric variations and the solar wind better. The
forecast is operated every day at 0 UT for next 24 hours. The model uses day of year, sunspot
number, F10.7 solar proxies, solar wind proton velocity, IMF By and Bz to the input. Prior 24 hour
values to the forecast are lined to the input at once. To represent the time dependences, 24 ofindividual NNs are constructed for each hour and concatenated at forecast. We introduce theoperational model and report the summary of current operation, and discuss several possibilities toimprove the forecast.
Keywords: Forecast, foF2, Neural network, Solar wind©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P21 -PEM04-P22

Japan Geoscience Union Meeting 2016

Preliminary development of radio propagation simulator for HF*Kornyanat Watthanasangmechai1, Mamoru Ishii1, Takashi Maruyama1, Tatsuhiro Yokoyama1, Susumu Saito2
1.National Institute of Information and Communications Technology, 2.Electronic Navigation ResearchInstitute
To investigate an ionospheric effect on the HF radio propagation, we are developing the radio
propagation simulator. Because radio waves in the high frequency (HF) band can be reflected back to
Earth by the ionosphere layer, they are widely used for long-distance communication. HF is not only
popular among amateur radio users, but it is also valuable remote communication during a disastere.g. Tsunami and big earthquake. Being involved in the ionosphere, an integrity of HF wave,
however, unavoidably relies on sunlight/ darkness of the transmission and reception sites, season,sunspot number, solar activity, aurora activity, and magnetic activity. While the maximum usable
frequency (MUF) has a direct variation with the electron density, the lower usable frequency
depends on the absorption in the D-layer of the ionosphere. This paper presents a preliminary
effort for an integration of the radio propagation knowledge and the ionospheric knowledge. The
current status of the simulator development will be reported.
Keywords: Radio propagation, HF, Ionosphere©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P22 -PEM04-P23

Japan Geoscience Union Meeting 2016

Nonlinear reflection process of linearly-polarized, broadband Alfven waves in the fastsolar wind
*Munehito Shoda1, Takaaki Yokoyama1
1.Graduate School of Science, University of Tokyo
Alfvén waves are frequently observed both in the solar atmosphere (DePontieu et al. 2007 Science,
Okamoto et al. 2007 Science) and the solar wind (Belcher & Davis 1971 JGR), and widely believed toplay a significant role in the coronal heating and the solar wind acceleration. Since thereflection of Alfvén waves triggers Alfvénic turbulence in the solar atmosphere and the solar wind(Matthaeus et al. 1999 ApJL, Dmitruk et al. 2002 ApJ), turbulent heating rate of the corona issensitive to the reflection rate. Comparison of recent studies (Suzuki & Inutuska 2005 ApJL,
Cranmer & van Ballegooijen 2005 ApJS) strongly suggest that the compressibility of plasma, in otherwords the nonlinearity of Alfvén waves, enhance the reflection rate up to 100-1000 times, whosemechanism is still unclear.
Using one-dimensional numerical simulations, we study the elementary process of Alfvén wave
reflection in a uniform medium, including nonlinear effects. In the linear regime, Alfvén wave
reflection is triggered only by the inhomogeneity of the medium, whereas in the nonlinear regime,
it can occur via nonlinear wave-wave interactions. Such nonlinear reflection (backscattering) is
typified by decay instability. In most studies of decay instabilities, the initial condition has
been a circularly polarized Alfvén wave. In this study we consider a linearly polarized Alfvén
wave, which drives density fluctuations by its magnetic pressure force. For generality, we also
assume a broadband wave with a red-noise spectrum. In the data analysis, we decompose thefluctuations into characteristic variables using local eigenvectors, thus revealing the behaviorsof the individual modes.
Different from circular-polarization case, we find that the wave steepening produces a new energy
channel from the parent Alfvén wave to the backscattered one. Such nonlinear reflection explains
the observed increasing energy ratio of the sunward to the anti-sunward Alfvénic fluctuations inthe solar wind with distance (Bavassano et al. 2000 JGR) against the dynamical alignment effect(Dobrowolny et al. 1980 Phys.Rev.Lett.).
Keywords: solar wind, Alfvén wave

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P23 -PEM04-P24

Japan Geoscience Union Meeting 2016

Solar energy transport with significantly suppressed velocity*Shota Arai1, Hideyuki Hotta1
1.Astorophysics Laboratory , Department of Physics , Faculty of Science , Chiba University
We carry out a series of 2D convection calculations with highly suppressed velocity. Thermal
convection in the solar interior is thought to maintain differential rotation and meridional
circulation. Although the solar equator is rotating faster than polar region, recent
high-resolution calculations with solar parameters accelerate the pole. This problem can be
attributed to over-excited thermal convection in numerical calculations. Local helioseismology also
supports this finding. Recent MHD simulations suggest that the small-scale Lorentz force is able tosuppress the convection velocity, but the suppression is not enough and has not been numericalconverged, i.e., higher resolution shows stronger suppression.
In this study, we assume that the Lorentz feedback in extremely high resolution, i.e., the sun,becomes stronger enough to explain equator acceleration and the result of the local
helioseismology. In order to investigate this extreme condition, we carry out series of 2Dhydrodynamics simulations with high viscosity mimicking the strong Lorentz force. The purpose of
our research is to investigate energy flux transported by the thermal convection. Even if thevelocity is reduced, convection needs to transport imposed energy flux at the bottom boundary.
Generally it is expected that upflow and down flow become hotter and cooler, respectively thanthose without viscosity. We also find that the correlation becomes better with high viscosity with
suppressing the small-scale chaotic motion.
Keywords: Sun, Thermal convection, Magnetic field©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P24 -PEM04-P25

Japan Geoscience Union Meeting 2016

A study for the improvement of SUSANOO-solar wind model*Toshihiro Ishida1, Kanya Kusano1, Daikou Shiota1
1.Institute for Space-Earth Environmental Research, Nagoya University
The Earth is exposed to solar wind that emanates constantly from the Sun and influences the
structure and dynamics of the magnetosphere of the Earth. Hence, the prediction of solar wind is
crucial for the space weather forecast.
In recent years, our group have developed a space weather prediction model: SUSANOO(Space-weather-forecast-Usable System Anchored by Numerical Operations and Observations), which canpredict the solar wind profile at the Earth’s orbit and high-energy electrons flux of the radiation
belt on the basis of three-dimensional MHD simulation of solar wind (SUSANOO-SW) [Shiota et al.,2014]. Although SUSANOO-SW may reproduce the large-scale three-dimensional structures of solar windon the basis of observation of the photospheric magnetic field, the model is not yet able to well
reproduce the observation of the short term variation of solar wind and the amplitude of fast solar
wind velocity.
In this research, we study the cause of deviation between the model and observations focusing on
the solar wind speed model which is used to specify the solar wind distribution on the innerboundary condition of SUSANOO-SW. We found that peculiar high speed structures aroundpseudostreamers, which must be formed by the Wang-Sheeley model [Arge and Pizzo, 2000], might be acause of degradation of reproducibility.
In order to improve it, we take into account not only of the expansion factor but also of themagnetic intensity based on a theoretical work by Suzuki [2006]. I will quantitatively evaluate theperformance of the new model, and discuss about what is needed to improve the predictability ofsolar wind model based on the comparison with the in-situ observation.
Keywords: solar wind©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P25 -PEM04-P26

Japan Geoscience Union Meeting 2016

Three-Dimensional MHD Simulation of the Interaction between CME and Ambient Plasma in
Solar Corona*Masaki Shirota1, Kanya Kusano1, Daikou Shiota1
1.Institute for Space-Earth Environmental Research, Nagoya University
Coronal mass ejections (CMEs) are one of main drivers of various disturbances in space weather. In
particular, the timing of arrival, the strength, and the amount of southward magnetic flux brought
by CMEs are important for the magnitude of the space weather disturbances, and those are depend on
the following factors: whether the CMEs hit the earth or not, speeds of the CMEs, and the magnetic
field structures within the CMEs. Because the factors are determined as a results of the dynamics
in their propagation as well as in formation in the solar corona, the understanding of theinfluence of ambient corona on the dynamics of CMEs is necessary for an improvement of space
weather forecast. However, what determines the structure and intensity of magnetic field of CME is
not yet well understood.
In this study, we performed magnetohydrodynamic simulations of a formation process of CMEs in thesolar corona, focusing on the interaction between an ejecting flux rope and its ambient field byextending the work by Shiota et al. (2010). We examined the dynamics of magnetic flux rope in threedifferent ambient plasma conditions: the uniform atmosphere, the hydrostatic atmosphere, and thesteady state of the solar wind.
In the uniform atmosphere case, the flux rope are decelerated very much with continues rotation
around the propagation direction as same as the previous study (Shiota et al. 2010). In contrast,
we found that in the other two cases the flux rope speed is much faster than in the uniform
atmosphere case because of a much weaker drug force in the stratified or steadily flowing plasma.
Since the magnetic interaction between the flux rope and the ambient field seems to be weaker inthose cases, the rotation of CME becomes weaker. We will discuss how the ambient plasma influences
the dynamics of the CMEs.
Keywords: magnetohydrodynamic, coronal mass ejections (CMEs), corona©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P26 -PEM04-P27

Japan Geoscience Union Meeting 2016

Mode Conversion of Alfven Waves Propagating in the Solar Chromosphere and Contribution to
the Heating*Shunya Kono1, Takaaki Yokoyama1
1.The University of Tokyo
Alfven waves, which are generated in the solar photosphere and propagate along magnetic flux tubes,
have been suggested to carry sufficient energy to the upper solar atmosphere and heat theatmosphere through wave dissipation. The chromosphere is an intermediate layer connecting thephotosphere to the corona. Propagation and dissipation of waves in the chromosphere regulate theenergy flux penetrating the corona. The chromospheric heating by waves is important forunderstanding the mechanism of solar atmospheric heating and solar wind acceleration. In thispresentation, we report on our numerical works of Alfven wave propagation along open flux tubes
from the solar convection zone to the corona. In 1.5-dimensional magnetohydrodynamic (MHD)
numerical simulations, it is shown that 60–90% of the upward-propagating Alfvenic pulse withfrequencies of 3–100 mHz are reflected at the transition region, which is the top boundary of thechromosphere. Meanwhile, most of the waves reflected at the transition region penetrate theconvection zone without being reflected at the bottom of the photosphere. These results suggestthat Alfven waves are unlikely to be trapped in the chromosphere. During the wave propagation in
the chromosphere, Alfven waves exhibit nonlinear effects with longitudinal wave generation. The
mode conversion rate is calculated with different plasma beta in the chromosphere. In the case withlow plasma beta (∼ 0.1–1), 0.01–1% of input Alfven wave energy is converted to the longitudinal
wave energy. This energy is almost comparable to the required energy for the chromospheric heating.
As plasma beta becomes larger and background Alfven speed becomes smaller in the chromosphere, more
longitudinal wave appears due to increase of nonlinearity of the Alfven wave. In the case with highplasma beta (∼ 1–10), the mode conversion rate becomes 1–10%. The generated longitudinal waves
carry sufficient energy to heat the chromosphere.
Keywords: chromosphere, wave, nonlinear, heating©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P27 -PEM04-P28

Japan Geoscience Union Meeting 2016

Influence of solar wind and ozone on the temperatures of the troposphere and stratosphere*Kazuyoshi Yamashita1, Kiminori Itoh2
1.Yokohama National University, 2.Inst.Env.Sci.&Technol.,Yokohama National Univ.
The correlation between global atmosphere and solar magnetic activity is evident though the cause
is not clear. In this presentation, we analyze the influence that solar wind and ozone give to theglobal atmosphere to examine the cause on the basis of the previous observations [1].
The AE index data were used to detect the influence of the solar wind on the total ozone and the
air temperature change of the troposphere and stratosphere.
In the analysis, the following factors were taken into account: 1)EPP-NOx effects on ozone at low
latitudes may be comparable to the effects of solar UV radiation [Callis et al., 2000, 2001;
Langematz et al., 2005; Rozanov et al., 2005]. 2) Since the ozone generated at low latitude isconveyed to the pole aria of the winter hemisphere, EPP-NOx has affected the ozone reduction of thepole area.
As the analysis result, showalter stability index which is calculated from the temperature of
500hPa and 850hPa in polar regions correlates with the AE index, Especially when the Arctic
Oscillation is changed from the positive phase to the negative phase, the tendency is strong.
This increase in high-energy particles with the solar wind, to reduce the stratospheric ozone
polar, it is possible to increase the amount of solar radiation reaching the troposphere, there isa possibility that influence the stability of the atmosphere.
Thus, changes in the stratospheric ozone due to the influence of the solar wind appears to affectthe climate of the troposphere.
Reference[1]K.Itoh, JpGU. 2008-2015
Keywords: atmospheric stability, AE index, AO index, ozone©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P28 -PEM04-P29

Japan Geoscience Union Meeting 2016

Space Weather and Terrestrial Weather during the Transition Period of the Solar Activity
in 13th and 14th Century: an Examination on Disaster Records in Yuan Dynasty.
*Hisashi Hayakawa2, Hiroko Miyahara5, Harufumi Tamazawa1, Hiroaki Isobe3,4, Ryuho Kataoka6,7
1.Kwasan and Hida Observatories, Graduate School of Science, Kyoto University, 2.Graduate School ofLetters, Kyoto University, 3.Graduate School of Advanced Integrated Studies in Human Survivability,
Kyoto University, 4.Kyoto University Unit of Synergetic Studies for Space, 5.Musashino Art
University, 6.National Institute of Polar Research, 7.SOKENDAISpace Weather and Terrestrial Weather during the Transition Period of the Solar Activity in 13thand 14th century: an examination on disaster records in Yuan Dynasty. In the 13th century, therapid fall down of the solar activity ended the Medieval Maximum (1100-1250) and started the Wolf
Minimum (1280-1340). This change of the solar activity also caused a considerable climate change on
the earth and brought an end of the Medieval Warm Period (10c-13c) and the Little Ice Age(14c-19c). In the 13th century, Eurasia witnessed an unexampled worldwide empire by the Mongolian
Empire and the trade routes across the Eurasia had gotten connected between the West and the East
under the "Pax Mongolica". Even this worldwide Empire could not conquer the contemporary climatechange and had disintegrated in the early Little Ice Age. It is frequently pointed out that hunger
or social unrests caused by extreme weathers are one of its biggest reasons. However, as for suchextreme terrestrial weathers, they have only gotten pointed out vaguely and they have left
unexamined till now. So, in this presentation, we treat the records of disasters in the China under
Mongolian rule (1235-1368) and show the detail of the extreme terrestrial weather caused in the
period during the transition of the solar activity, shown by the records of carbon-14 in treerings. Historical records provides important information on the regional differences of solar
influence on climate. It also gives some clues on the ocean-atmospheric circulation during thetime.
Keywords: Wolf Minimum, Medieval Warm Period, solar activity, Extreme Terrestrial Weathers©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P29 -PEM04-P30

Japan Geoscience Union Meeting 2016

Aurora Candidates from the Chronicles of Qing Dynasties for Decoding Past Solar Activities*Akito Davis Kawamura1, Hisashi Hayakawa2, Haruhumi Tamazawa1, Hiroaki Isobe3,4
1.Kwasan Observatory, Kyoto University, 2.Graduate School of Letters, Kyoto University, 3.The
Graduate School of Advanced Integrated Studies in Human Survivability, Kyoto University, 4.Unit of
Synergetic Studies for Space, Kyoto University, Japan
We present the survey result of observational records of auroras in chronicles of Qing dynasties,

Qingshigao, the draft chronicle of Qing dynasty (1644-1912 CE). In total we found 111 records ofaurora candidates associated with the keywords such as vapor (qi), cloud (yun), and light ( guang). Among the 111 records we found, 14 records are considered as very likely to be low latitudeauroras with corresponding records of simultaneous observation in the western world, and 6 records
are newly found low latitude aurora candidates after moon phase analysis in order to eliminate apossibility of atmospheric optics involving. Some of our presenting candidates of low latitudeaurora are dated during the Maunder minimum, and therefore we would suggest our presenting data
potentially helpful for further discussion on past solar activities.
Keywords: Aurora, Space Weather, Historical Resources©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P30 -PEM04-P31

Japan Geoscience Union Meeting 2016

Development of user-oriented space environment prediction model for individual satellite*Tsutomu Nagatsuma1, haruhisa matsumoto2, Kiyokazu Koga2, Masao Nakamura3, Mamoru Ishii1
1.National Institute of Information and Communications Technology, 2.Japan Aerospace Exploration
Agency, 3.Osaka Prefecture University
Geospace environment is dynamically changing depending on the solar wind conditions. As a result,space environment disturbances, such as substorms and relativistic electron enhancements are
occurred. These are the key subjects of space weather research. On the contraly, there are numbersof commercial satellites operated in geospace. These satellites sometimes faced on the hazardous
conditions because of geospace disturbances. Changing the particle environment surrounding
individual satellite causes spacecraft charging problem. Less than 100 keV energy of charged
particles, and more than 500 keV energy of charged particles cause surface and internal charging tosatellites, respectively. Spacecraft charging is one of the major reasons of spacecraft anomaly. To
mitigate the risk of satellite anomaly, prediction of middle to high energy particle environment in
geospace is important.
However, the risk of spacecraft anomaly is also depend on the specification of the satellite (e.g.
surface materials, radiation tolerance, etc.). Therefore, the prediction of space environment isstill not enough for satellite operators. These information should be interpreted to the risk of
individual satellite.
To estimate a risk of spacecraft charging for individual satellite, we try to combine forecastingmodel of space environment and engineering model for individual satellite. Based on the combinationof these models, we will provide specific information of charging risk for individual satellite. In
this presentation, we will introduce our approach of developing user-oriented space environment
prediction model for individual satellite, and our initial results.
Keywords: Space Weather Forecast, Spacecraft Charging, User-Oriented©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P31 -PEM04-P32

Japan Geoscience Union Meeting 2016

Space weather effects on aeronautical communication, navigation and surveillance systems*Susumu Saito1, Mamoru Ishii2
1.Navigation Systems Department, Electronic Navigation Research Institute, 2.National Institute ofInformation and Communications Technology
Space weather can be defined as the conditions on the sun and in the solar wind, magnetosphere,
ionosphere, and thermosphere that can influence the performance and reliability of space-borne andground-based technological systems.
It becomes more important especially when the reliability are of relevance. Aeronauticalapplications are one of those which requires high level of reliability and safety. In fact,
International Civil Aviation Organization (ICAO) is working on standardizing the space weather
information for aeronautical operations.
The main objective of this paper is to present necessary space weather studies to which the science
community are expected to contribute to enhance the performance, reliability and efficiency ofaeronautical communications, navigation and surveillance (CNS) systems. Space weather phenomena
which can influence the aeronautical CNS systems are presented from the operation point of view.
Possible impacts of space weather phenomena on aeronautical CNS systems and necessary space weather
studies to evaluate the operational impact and devise effective mitigation methodology are
discussed.
Keywords: aeronautical applications, ionosphere, communications, navigation, and surveillancesystems©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P32 -