PEM04-01

日本地球惑星科学連合2016年大会

太陽地球圏環境予測プロジェクト（PSTEP）の挑戦
Challenge of PSTEP (Project for Solar-Terrestrial Environment Prediction)*草野 完也1*Kanya Kusano1
1.名古屋大学宇宙地球環境研究所
1.Institute for Space-Earth Environmental Research, Nagoya University
我々が生きる太陽地球圏の環境は太陽活動に起因して大きく変動しますが、そのメカニズムは未だに十分解明されていません。このため、幅広い宇宙利用と高度な情報化が進んだ現代社会は太陽地球圏の環境変動に対して潜在的なリスクを抱えています。太陽地球圏環境予測プロジェクト(PSTEP)は、こうした問題の解決を目指して文部科学省科学研究費補助金新学術領域によって組織された全国的な研究プロジェクトです。PSTEPには９０
名以上の研究者が参加し、４つの計画研究と公募研究の有機的な連携を通して太陽地球圏環境変動についての科学研究と予測研究を相乗的に発展させることを目指しています。これによって、太陽フレア発生機構、地球放射線帯の生成機構、太陽活動の気候影響機構といった重要な科学課題を解決すると同時に、激甚宇宙天気災
害に備える社会基盤の形成を推進しています。本講演ではPSTEPの主要なねらいとその研究戦略を紹介します。
キーワード：宇宙天気、宇宙気候、予測
Keywords: space weather, space climate, prediction©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-01 -PEM04-02

日本地球惑星科学連合2016年大会

宇宙天気情報利用におけるニーズ・シーズマッチングの検討
Analysis of Needs-Seeds Matching for Using Space Weather Information*石井 守1、垰 千尋1*Mamoru Ishii1, Chihiro Tao1
1.国立研究開発法人情報通信研究機構
1.National Institute of Information and Communications Technology
情報通信研究機構では、2005年よりほぼ毎年「宇宙天気ユーザーズフォーラム」を開催してきたことに加え、2013・14年の2年にわたり宇宙天気情報の利用者に対して姉k-戸やヒアリングを通しそのニーズの調査を行ってきた。
2015年に新学術領域「太陽地球圏環境予測」（PSTEP)が採択された。この中の主要な目標の一つとして「宇宙天気情報の双方向システムの構築」が挙げられている。この実現のために、新たに「宇宙天気ユーザー協議会」を立ち上げるとともに、研究者側から提供できる情報と、利用者が必要としている情報の調査を行い、ギャップ解析およびマッチングに向けた分析を行っている。
現在、宇宙天気情報の実利用検討で最も進んでいる分野として、航空運用が挙げられる。2014年には、国際民間航空機関（ICAO)で航空気象を規定する第三付属書の改訂が検討され、使用される宇宙天気情報の仕様が示された。しかしながら航空関係者にとってはこの利用について未だ十分な理解を得られているとは言えない状況である。このような事例を挙げつつ、ニーズ・シーズマッチングに向けた議論を行う。
キーワード：宇宙天気、市場調査、航空運用
Keywords: space weather, user investigation, aviation©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-02 -PEM04-03

日本地球惑星科学連合2016年大会

ベクトル磁場と彩層発光を用いた機械学習による太陽フレア予測
Solar Flare Prediction with Vector Magnetogram and Chromospheric Brightening using
Machine-learning*西塚 直人1、久保 勇樹1、杉浦 孔明1、田 光江1、亘 慎一1、石井 守1*Naoto Nishizuka1, Yuki Kubo1, Komei Sugiura1, Mitsue Den1, Shinichi Watari1, Mamoru Ishii1
1.国立研究開発法人

情報通信研究機構

1.National Institute of Information and Communications Technology
Solar flares have been empirically predicted based on the solar surface observations. Before large
class of flares, photospheric magnetic field in the active region becomes complex and sharp
magnetic neutral lines are formed. It is also known that chromospheric brightening recurrently
occurs at around the neutral lines. In NICT, solar flares occurring in the next 24 hours have been
predicted by scientists in the daily forecast operations, but the flare mechanism has not been wellrevealed and we still have a difficulty in predicting flares with high accuracy and good
confidence. Currently, we can access huge amount of observation data, so we developed a system toautomatically predict flares using the near real-time observation data by satellites and themachine-learning technique.
We used observation data sets taken by SDO and GOES satellites during 2010-2015: (1) line-of-sightdirection magnetogram and vector magnetogram data by HMI/SDO, (2) lower chromospheric brightening
data by AIA 1600 Angstrom filter/SDO, and (3) soft X-ray emission by GOES. Firstly, we
automatically detect active regions using full-disk images of magnetogram every 1 hour, to predicta flare class occurring in the region in the next 24 hours. Secondly, we extract solar features foreach region, i.e., the maximum magnetic field strength, the maximum gradient of magnetic field in
the line-of-sight direction, the number of magnetic neutral lines, the maximum length of neutrallines, the magnetic free energy, the shear angle, the time variations of magnetic field
configurations, the history of X/M-class flares, the background GOES X-ray emission, and theactivity of chromospheric brightening. Thirdly, we apply the machine-learning technique to thedataset of solar features to predict flares. We divided the total data set into two for training
and test. We adopted three machine-learning techniques for comparison: the support vector machine(SVM), the k-nearest neighbor (k-NN) and the extra random trees (ERT). As a result, we succeeded inachieving good prediction of X-class flares, as verified by the True Skill Score (TSS) larger than0.7, which is better than human forecast operations (TSS~0.5). In this presentation, we would liketo introduce our flare predictions model and to discuss flare triggering mechanism.
キーワード：宇宙天気予報、太陽フレア、統計解析、機械学習、光球ベクトル磁場、彩層
Keywords: Space Weather Forecast, Solar Flare, Statistical Analysis, Machine-Learning, Photosphericvector Magnetic field, Chromosphere©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-03 -PEM04-04

日本地球惑星科学連合2016年大会

汎用時系列予報機UFCORINを用いた太陽フレア予測の進展について
Solar Flare Prediction Studies Using Universal Time Series Predictor UFCORIN*村主 崇行1、羽田 裕子2、柴山 拓也4、磯部 洋明2、根本 茂3,2、駒崎 健二3、柴田 一成2*Takayuki Muranushi1, Yuko Hada Muranushi2, Takuya Shibayama4, Hiroaki Isobe2, Shigeru Nemoto3,2,
Kenji Komazaki3, Kazunari Shibata2
1.国立研究開発法人理化学研究所

計算科学研究機構、2.京都大学、3.株式会社ブロードバンドタワー、4.名

古屋大学
1.RIKEN Advanced Institute for Computational Science, 2.Kyoto University, 3.BroadBand Tower, Inc.,
4.Nagoya University
我々は、自動化された宇宙天気予報を提供するためのソフトウェアプラットフォームUFCORIN(Universal
Forecast Constructor by Optimized
Regression of INputs)を開発し、それを用いて宇宙天気予報を研究している。
これまでの実験では、2011-2012年の二年間の期間において、GOES衛星の観測による太陽X線フラックスの時系列データを予測対象とし、GOESデータの過去デー
タおよびSDO/HMIによる太陽面視線垂直磁場画像データをもとに、6160通りの予報戦略を試し、その性能比較を行った(Muranushi et al. 2015)。
太陽フレア予測の研究では、
Bloomfield et. al(2012)の提案以来、予報性能の指標としてTSS(True Skill Statistics)が広く使われている。ところが我々は、数多くの予報戦略を比較する
場合、TSSの値は、予報戦略どうしの平均値の差にくらべ、交差検定データを変えたときのゆらぎが大きすぎて、適切な性能比較ができないことを発見した。
そこで、交差検定データごとに、各予報戦略のTSSの偏差値($z$-value)を算出したところ、交差検定データを変えても一貫して高い偏差値を示す予報戦略の存在が観察された。我々はこの偏差値を用いる手法を、数多くの予報戦略を比較する手段として提案する。
本研究の中で、X,M,Cクラスフレアに対する最善の予報戦略のTSSはそれぞれ$0.75\pm0.07$, $0.48\pm0.02$,
および $0.56\pm0.04$であった。
また、我々は(Muranushi et al. 2015)を元に、２０１５年８月よりリアルタイムフレア予報を提供している。この予報はサーバ障害等によるダウンタイムがあるものの、１２分おきに自動的に提供されている。本発
表ではこのリアルタイム予報実験の進捗についても報告する。
キーワード：宇宙天気予報、フレア予測
Keywords: Space Weather Forecast, Flare Forecast©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-04 -PEM04-04©2016. Japan Geoscience Union. All Right Reserved.

日本地球惑星科学連合2016年大会- PEM04-04 -PEM04-05

日本地球惑星科学連合2016年大会

宇宙及び航空機高度における放射線防護：WASAVIES開発の現状と今後の展望
Radiation Protection of Humans in Space and Aviation: Current States and Future Needs on
the Warning System for Aviation Exposure to SEP (WASAVIES)*佐藤 達彦1、石井 守2、片岡 龍峰3、久保 勇樹2、簑島 敬4、三好 由純5、永松 愛子6、塩田 大幸5、高島 健6、保田 浩志7*Tatsuhiko Sato1, Mamoru Ishii2, Ryuho Kataoka3, Yuki Kubo2, Takashi Minoshima4, Yoshizumi Miyoshi5,
Aiko Nagamatsu6, Daikou Shiota5, Takeshi Takashima6, Hiroshi Yasuda7
1.日本原子力研究開発機構、2.情報通信研究機構、3.極地研、4.海洋研究開発機構、5.名古屋大学、6.宇宙航空研究開発機構、7.広島大学
1.JAEA, 2.NICT, 3.NIPR, 4.JAMSTEC, 5.Nagoya Univ., 6.JAXA, 7.Hiroshima Univ.
Forecast of radiation doses for astronauts as well as aircrews due to the exposure to solar
energetic particles (SEP) is one of the greatest challenges in space weather research. In last 5
years, we have developed a WArning System for AVIation Exposure to Solar energetic particles:
WASAVIES. In this system, the SEP fluxes incident to the atmosphere are calculated by physics-basedmodels, and they are converted to radiation doses using a database developed on the basis of
air-shower simulation. However, it takes approximately 2.5 hours to determine the parameters usedin the physics-based models after the detection of GLEs, and thus, the current WASAVIES cannot
predict doses during the peak of GLEs. Therefore, we are trying to reduce the time for evaluating
the parameters, as well as to develop a nowcast system for the radiation dose due to SEP exposure,under the framework of Project for Solar-Terrestrial Environment Prediction (PSTEP,
http://www.pstep.jp/) in Japan. A brief outline of WASAVIES together with our future strategy will
be presented at the meeting.
キーワード：太陽高エネルギー粒子、放射線被ばく、宇宙天気
Keywords: SEP, Radiation Exposure, Space Weather©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-05 -PEM04-06

日本地球惑星科学連合2016年大会

Recent Progress in Space Weather Modeling and Forecasting at NOAA's Space Weather
Prediction Center
Recent Progress in Space Weather Modeling and Forecasting at NOAA's Space Weather
Prediction Center*Berger Thomas1*Thomas Berger1
1.National Oceanic and Atmospheric Administration
1.National Oceanic and Atmospheric Administration
We discuss the current state of the art of space weather modeling and forecasting at the NOAA Space
Weather Prediction Center (SWPC) in Boulder, Colorado. Recent progress in modeling the solar windusing a data assimilative flux transport model (ADAPT) from the Air Force Research Laboratory(AFRL) has shown that incorporating current and modeled solar magnetic field data results in abetter correlation with measurements of the solar wind at the ACE spacecraft in L1 orbit. SWPC isalso transitioning the University of Michigan's "Geospace" model to operations, enabling 15-30
minute forecasts of geomagnetic storming and regional K-value predictions. In addition SWPC and the
University of Colorado Cooperative Institute for Research in the Environmental Sciences (CIRES) aredeveloping the Whole Atmosphere Model (WAM) and the Ionosphere Plasmasphere Electrodynamics (IPE)
coupled system to enable three-day forecasts of ionospheric conditions as well as neutral
atmosphere density for satellite drag calculations. In accordance with the new National Space
Weather Strategy released by the White House in October 2014, these and other models and products
will be integrated into the Space Weather Forecast Office to enable SWPC forecasters to deliver
impact-based decision support services to satellite operators, commercial airlines, GNSS users, andelectrical grid operators to protect critical infrastructure from the threat of extreme space
weather events.

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-06 -PEM04-07

日本地球惑星科学連合2016年大会

NASA Heliophysics and the Science of Space Weather
NASA Heliophysics and the Science of Space Weather*Clarke Steven1*Steven W Clarke1
1.NASA Headquarters
1.NASA Headquarters
NASA formulates and implements a national research program for understanding
the Sun and its interactions with the Earth and the solar system and how these
phenomena impact life and society. This research provides theory, data, andmodeling development services to national and international space weather efforts
utilizing a coordinated and complementary fleet of spacecraft, called the
Heliophysics System Observatory (HSO), to understand the Sun and its interactions
with Earth and the solar system, including space weather. NASA’s space-based
observational data and modeling efforts have provided significant contributions tothe science of space weather. Current and future space weather research will
provide key information to improve the ability of the United States and its
international partners to prepare, avoid, mitigate, respond to, and recover from thepotentially devastating impacts of space-weather events.

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-07 -PEM04-08

日本地球惑星科学連合2016年大会

Scientific research in support of space weather goals*Michael Hesse1
1.NASA Goddard Space Flight Center
Unlike terrestrial weather, space weather is immature from a scientific point of view. While thelast decades have seen tremendous scientific progress, which, among others, manifested itself inform of advanced space weather models, many key scientific processes underpinning space weather
remain poorly understood or not understood at all. These processes span the gamut of Heliophysics
domains; starting from magnetic filed generation processes in the solar interior and reaching toEarth's upper atmosphere, where we still lack kowledge of the processes responsible for ionosphericscintillations. In addition, we are in many, rather fundamental from a space weather point of view,
cases not able to predict with any confidence the expected amplitudes of space weather phenomena.
This presentation will review scientific progress to-date, and attempt to map out a path forward
toward the desired quantitative and accurate predictabily.
Keywords: Space weather, Space research, Heliophysics©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-08 -PEM04-09

日本地球惑星科学連合2016年大会

Geomagnetically induced currents: the latest science, engineering and policy actions in
the US*Antti Aleksi Pulkkinen1
1.The National Aeronautics and Space Administration, Goddard Space Flight Center
Geomagnetically induced currents (GIC) flowing in long manmade conductor systems have become one of
the main space weather concerns. The potential for widespread problems in operating high-voltage
power transmission systems during major geomagnetic storms has prompted increasing federal
regulatory, science, industry and public interest in the problem. The impact caused by extreme
storm events has been of special interest and consequently much of the recent GIC research has been
focused on defining extreme GIC event scenarios and quantifying the corresponding transmission
system response. In addition, there is an elevated need for developing next generation GIC
prediction products for the power industry. In this presentation, I will discuss the latest
science, engineering and policy actions around the topic especially in the US. Perhaps the mostsignificant policy action are the standards work pushed by the US Federal Energy Regulatory
Commission. GIC are centerpiece also in the newly released National Space Weather Strategy
reflecting the strong interest in the topic at the highest levels of the US government. Much of therecent progress in understanding GIC and its impact on power grids has resulted from improved
scientific community-power industry interactions. The common language and information exchangeinterfaces established between the two communities have led to significant progress intransitioning scientific knowledge into detailed impacts analyses. We also face a number of futurechallenges in specifying GIC, for example, in terms of more realistic modeling of thethree-dimensional geomagnetic induction process. I will discuss briefly some of these futurechallenges.
Keywords: Space weather, Geomagnetically induced currents©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-09 -PEM04-10

日本地球惑星科学連合2016年大会

地磁気データから変電所GICの推定
Empirical estimation of GICs from the geomagnetic data in Japan*藤田 茂1、藤井 郁子1、桝田 祐里1*Shigeru Fujita1, Ikuko Fujii1, Yuri Masuda11.気象庁気象大学校
1.Meteorological College, Japan Meteorological Agency
Pulkkinen et al (2007) proposed the new method of estimating geomagnetically induced currents(GICs) at a transformer station by employing the linear relation between the GICs and thecorresponding geomagnetic variations as
GIC(ω)=A(ω)By(ω)+B(ω)Bx(ω) (1)By using the two transfer functions in the frequency domain (A(ω) and B(ω) in Eq. (1)), we obtain
GIC(t)=∫ A(τ)By(t-τ)dτ + ∫B(τ)Bx(t-τ)dτ (2)This method (the transfer function method) successfully reproduced the GICs from the geomagnetic
variations in Finland [Pulkkinen et al., 2007] and in Hokkaido [Pulkkinen et al., 2010]. However,as the electrical conductivity distributions in both areas are rather uniform, it is important toevaluate how this method is applied to GICs observed at a station in other area of Japan withheterogeneous conductivity distribution. This is the motivation of this research. We employ
one-minute values of the GICs observed at a transformer station and those of the geomagnetic data
at Kakioka Magnetic Observatory during the Halloween event.
To confirm how this method is effective, we need to investigate how the GICs during one event are
reproduced from the geomagnetic data in this event with the transfer function obtained from theother event. Fortunately, the Halloween event has two activities on Oct/30 (the event #1) and on
Oct/31 (the event #2), we can calculate separately two transfer functions for the two events.
First, we confirm that the transfer functions obtained from the events are essentially identical.
This fact indicates that the transfer function method by Pulkkinen et al. (2007) is applicable to
the GIC data in Japanese transformer station. Next, the GICs in the event #1/#2 are estimated fromthe geomagnetic data in the event #2/#1 and the transfer function of the event #2/#1. Whencalculating GICs in time domain in Eq. (2), we noticed that the integral from t=0 to 50min
reproduces sufficiently accurate GICs. This fact is a little bit different from Pulkkinen et al.
(2007) who estimated the GICs through the integral only at t=0 and 1min. At last, we confirm thatthe reproduced GICs are essentially similar to the observed ones.
In the last, we estimate the GICs at the transformer station in the magnetic storm in 1989 whichcaused the large-scale blackout in Canada and US.
References
Pulkkinen, A., R. Pirjola, and A. Viljanen (2007), Determination of ground conductivity and systemparameters for optimal modeling of geomagnetically induced current flow in technological systems,
Earth Planets Space, 59, 999-1006.
Pulkkinen, A., R. Kataoka, S. Watari, and M. Ichiki (2010), Modeling geomagnetically induced
currents in Hokkaido, Japan Advances in Space Research, 46, 9, 1087-1093.
キーワード：地磁気誘導電流、変電所、伝達関数©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-10 -PEM04-10

日本地球惑星科学連合2016年大会

Keywords: geomagnetically induced current, transformer station, transfer function©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-10 -PEM04-11

日本地球惑星科学連合2016年大会

グローバルMHDシミュレーションを用いたバスティーユイベント時の極冠電位差飽和の研究
Polar cap potential saturation during the Bastille day storm using global MHD simulation*久保田 康文1、長妻 努1、田 光江1、田中 高史2、藤田 茂3*Yasubumi Kubota1, Tsutomu Nagatsuma1, Mitsue Den1, Takashi Tanaka2, Shigeru Fujita3
1.情報通信研究機構、2.九州大学、3.気象大学校
1.National Institute of Information and Communications Technology, 2.Kyushu University,
3.Meteorological College
We are developing a real-time numerical simulator for the solar wind-magnetosphere-ionosphere
coupling system using next generation magnetosphere-ionosphere coupling global MHD simulation
called REPPU (REProduce Plasma Universe) code. The feature of simulation has an advanced robustness
to strong solar wind case because a triangular grid is used, which is able to calculate in theuniform accuracy over the whole region. Therefore we can simulate extreme event such as theBastille day storm. The resolution is 7682 grids in the horizontal direction and 240 grids in theradial direction. The inner boundary of the simulation box is set at 2.6 Re. We investigate thereproduction of the magnetosphere-ionosphere coupling simulation in strong solar wind case.
Therefore we compared the simulation results with the observation of the Bastille day storm event(2000/7/15), in which the solar wind velocity is above 1000 km/s and the value of Bz reached -60
nT. Especially, we focus the CPCP saturation and time variation because the CPCP represents thevalue of magnetospheric - ionospheric convection strength via region 1 current. The CPCP depends onsolar wind electric field, dynamic pressure and ionospheric conductivity [Siscoe et al., 2002;
Kivelson et al., 2008]. The model of Kivelson et al. [2008] shows a good reproduction to the CPCP
variation. However their study assumes that the ionospheric conductivity is constant. The
conductivity in our simulation of the Bastille day event is varied by the auroral activity. In thislecture, we discuss the effect of both the auroral conductance and solar EUV-driven conductance to
CPCP saturation.
キーワード：グローバル磁気圏シミュレーション、極冠電位差、極端現象
Keywords: global MHD simulation, polar cap potential, extreme event©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-11 -PEM04-12

日本地球惑星科学連合2016年大会

Space weather forecast of energetic particles and extreme space weather of magnetic storms
Space weather forecast of energetic particles and extreme space weather of magnetic storms*片岡 龍峰1*Ryuho Kataoka1
1.国立極地研究所
1.National Institute of Polar Research
I review our recent research activities on the space weather forecast of energetic particles,
including galactic cosmic rays, solar protons, ring current, and radiation belt electrons.
Theoretical approaches on the extreme space weather of geomagnetically induced currents and on
extreme space climate during grand minima are also discussed. A new citizen science approach toinvestigate world-wide aurora sightings during extreme magnetic storms is also introduced.

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-12 -PEM04-13

日本地球惑星科学連合2016年大会

What is the Largest Flare that can Occur on the Sun?
*Jon Linker1, Cooper Downs1, Tibor Torok1, Viacheslav Titov1, Zoran Mikic1, Roberto Lionello1, Ronald
Caplan1, Pete Riley1
1.Predictive Science Inc.
The question of whether so-called superflares (energies from 1033-1035 ergs) could occur on the Sun
is of great interest scientifically. There are also obvious practical (space weather) implications.
Shibata et al. (2013) suggested that flares on the order of 1034 ergs could occur every 800 years
on the Sun, while Schrijver et al. (2012) argued that the magnetic energy for such a flare would
require a sunspot 20 times greater then ever observed, and that 1033 ergs was a practical upper
limit for flares.
Major solar eruptions such as X-class flares and very fast coronal mass ejections originate inactive regions on the Sun. The energy that powers these events is believed to be stored as freemagnetic energy (energy above the potential field state) prior to eruption. Therefore, the maximum
free energy that can be stored in an active region bounds the largest possible eruption that canemanate from it. Using line-of-sight or vector magnetograms, the maximum energy that can be stored
in a region can be estimated with the aid of the Aly-Sturrock theorem. We have investigated theactive regions where the largest flares in the last 30 years have originated. We have found six
cases where the maximum free energy is on the order of or greater than 1034 ergs. Our results
suggest that 1034 erg solar flares cannot be ruled out based on magnetic energy storage.

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-13 -PEM04-14

日本地球惑星科学連合2016年大会

Solar Origin of a Sequence of SEP-Producing CMEs via the "Lid Removal" Mechanism*Alphonse Sterling1
1.NASA/MSFC
Both coronal mass ejections (CMEs) and solar energetic particle (SEP) events are of concern forspace weather. Here we report on the solar source of a pair of CMEs that produced a strong SEP
event. The CMEs resulted from back-to-back ejective eruptions from a single active region on 2012
January 23. We examine the onset of these eruptions using magnetograms and EUV images from the HMI
and AIA instruments on the Solar Dynamics Observatory (SDO) spacecraft, and EUV images from the
STEREO spacecraft. Cheng et al. (2013) showed that the first eruption's (``Eruption 1'') flux rope
was apparent only in ``hotter'' AIA channels, and that it removed overlying field that allowed thesecond eruption (``Eruption 2'') to begin via ideal MHD instability; here we say Eruption 2 began
via a ``lid removal'' mechanism. We show that during Eruption-1's onset, its flux rope underwent``tether weakening'' (TW) reconnection with the field of an adjacent active region. Standard flare
loops from Eruption 1 developed over Eruption-2's flux rope and enclosed filament, but theseoverarching new loops were unable to confine that flux rope/filament. Eruption-1's flare loops,
from both TW reconnection and standard-flare-model internal reconnection, were much cooler thanEruption-2's flare loops (GOES thermal temperatures of ~9 MK compared to ~14 MK). This eruption
sequence produced a strong solar energetic particle (SEP) event (10 MeV protons, >10^3 pfu for 43hrs), apparently starting when Eruption-2's CME blasted through Eruption-1's CME at 5---10 R_s.
This occurred because the two CMEs originated in close proximity and in close time sequence:
Eruption-1's fast rise started soon after the TW reconnection; the lid removal by Eruption-1's
ejection triggered the slow onset of Eruption 2; and Eruption-2's CME, which started ~1 hr later,
was three times faster than Eruption-1's CME.
Keywords: Coronal Mass Ejection (CME) Onset, Solar Energetic Particles (SEPs), Solar Filament
Eruptions, Solar Flares©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-14 -PEM04-15

日本地球惑星科学連合2016年大会

Solar Corona and Space Weather*Philippe Lamy1
1.Laboratoire Astrophysique de Marseille
It is now well established that the activity in the solar corona plays a major role in theprocesses at the origin of space weather effects in the heliosphere. The almost uninterrupted
observations by the LASCO coronagraph onboard SOHO since January 1996 have allowed an unprecedented
view of the coronal activity over almost two solar cycles 23 and 24 which reflects to a larger
extent the magnetic activity of the Sun. I will report on the evolution of the corona and its large
scale structure through various parameters, such as its radiometry and its three-dimensional
electron density. The temporal variations will be compared with standard solar indices and various
proxies of solar activity in order to identify the driving mechanisms that control the activity of
the corona. Coronal mass ejections (CMEs) are strongly controlling space weather and the ARTEMIS-II
catalog based on their automatic detection on high-quality calibrated synoptic maps of the corona
allows performing an unbiased statistical analysis of their properties and investigate how they
evolve with solar activity. I will present the results for occurrence and mass rates, waitingtimes, position angle, angular width, kinetic energy, and mass flux first globally and thenseparately for the two solar cycles 23 and 24 emphasizing the differences. I will further compare
the statistical properties of CMEs with those of the standard indices of solar activity as well as
those of their potential progenitors, flares and eruptive prominences.
Keywords: Sun, Coronal activity, Space weather©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-15 -PEM04-16

日本地球惑星科学連合2016年大会

世界最大の太陽ダイナモ計算で明らかになった大規模磁場生成のメカニズム
Generation mechanism of large-scale magnetic field revealed with high-resolution solar
dynamo calculation*堀田 英之1、Rempel Matthias2、横山 央明3*Hideyuki Hotta1, Matthias Rempel2, Takaaki Yokoyama3
1.千葉大学大学院理学研究科、2.高高度観測所、3.東京大学
1.Graduate School of Science, Chiba University, 2.High Altitude Observatory, 3.University of Tokyo
We carry out series of high-resolution solar dynamo calculations in spherical geometry toinvestigate generation mechanism of large-scale magnetic field. Solar observations indicate
large-scale magnetic field in the solar interior in spite of the chaotic and turbulent fluid
motion. Recent high-resolution calculations show that higher-resolution calculations generate
weaker large-scale magnetic field, since small-scale turbulence tends to destruct the coherent
large-scale magnetic field. In order to address this issue, we carry out a series ofhigher-resolution calculations. In our "middle"-resolution calculation, we find the same result as
previous studies, i.e., when we increase the resolution, the large-scale magnetic field loses its
energy. In our unprecedentedly high-resolution calculation, however, large-scale magnetic energy isrecovered. In the calculation, we find an efficient small-scale dynamo which leads to strong
Lorentz feedback in the small scale. The small-scale turbulent motion, which tends to destructs thelarge-scale magnetic field is suppressed. As a consequence, the large-scale magnetic field ismaintained even with large Reynolds numbers.
キーワード：太陽、熱対流、ダイナモ
Keywords: Sun, Thermal convection, Dynamo©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-16 -PEM04-17

日本地球惑星科学連合2016年大会

Modeling the thermosphere ionosphere system and space weather impacts*Timothy J Fuller-Rowell1
1.University of Colorado Boulder
The thermosphere-ionosphere-plasmasphere system has several direct impacts on space weather.
Uncertainty in thermospheric neutral density affects satellite drag, orbit prediction, andcollision avoidance. Variations in total electron content, together with steep gradients in plasma
density, disrupts GNSS navigation signals and positioning accuracy, affecting a range of users
including civil aviation. Changes in ionospheric layers modifies HF propagation due to absorption
in the D-region and changes in reflection from F-region positive and negative storm phases. During
a geomagnetic storm these changes can be dramatic. The modeling challenges are significant anddiverse. The response of the system to geomagnetic storms has to capture dynamic neutral densitychanges, huge increases in storm-enhanced plasma densities by a factor of five, followed by extreme
negative phases where the ionosphere can be severely depleted. During geomagnetically quieter
conditions the day-to-day changes can be more subtle. The impact of waves propagating frominstabilities in stratospheric jets or convective storms in the troposphere, produce persistentionospheric variability perturbing HF propagation. Predicting the day-to-day variability ofequatorial ionospheric irregularities, and their impact on satellite communication and navigation,
remains a challenge, although there are hints that variability of lower atmosphere waves may beplaying a role. Improvement in thermosphere-ionosphere and whole atmosphere models show promise inbeing able to simulate the response of the system to solar, geomagnetic, and lower atmosphere
forcing with a goal of mitigating some of the impacts of space weather on operational system.
Keywords: Thermosphere-Ionosphere Modeling, Space Weather, Satellite drag, Geomagnetic storms©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-17 -PEM04-18

日本地球惑星科学連合2016年大会

Effects of energetic particle precipitation and solar irradiance on ozone*Alessandro Damiani1, Bernd Funke2, Manuel López Puertas2, Michelle L. Santee3
1.Japan Agency for Marine-Earth Science and Technology, Japan, 2.Instituto de Astrofísica deAndalucía,CSIC, Spain, 3.Jet Propulsion Laboratory, California Institute of Technology, USA
The term energetic particle precipitation (EPP) commonly refers to particles of different energy
which routinely impact the polar regions. EPP ionizes the atmosphere and triggers catalytic cyclesof ozone depletion driven by odd nitrogen (NOx) and odd hydrogen (HOx) species. While the mostenergetic particles can directly affect ozone in the mesosphere, during winter the (almost)continuous flux of auroral electrons produces high NOx amounts which can be transported downwards
inside the polar vortex and influence stratospheric ozone. On the other hand, the wavelength
dependence of the solar irradiance variation can induce stratospheric ozone changes in phase withsolar activity. Here, we investigated ozone variability in response to EPP and solar activity
during the 1979-2014 period by combining satellite ozone observations from Solar Backscatter
Ultraviolet Radiometer and Microwave Limb Sounder on Aura. In particular, we analyze thecorrelation of the polar ozone variability with EPP and with solar irradiance in an attempt todistinguish between the two effects and to quantify the ozone variations caused by EPP on long timescales.
Keywords: Energetic particle precipitation (EPP), ozone, solar radiation©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-18 -PEM04-19

日本地球惑星科学連合2016年大会

脈動オーロラに伴う高エネルギー電子がもたらす大気微量成分変動の解明に向けた国際共同研究
International joint study of EEP effects on the atmospheric minor components during
pulsating aurora*大山 伸一郎1、三好 由純1、齊藤 慎司1、Turunen Esa2、Kero Antti2、Partamies Noora4、Verronen Pekka3、Manninen Jyrki2、Virtanen Ilkka2、Raita Tero2*Shin-ichiro Oyama1, Yoshizumi Miyoshi1, Shinji Saito1, Esa Turunen2, Antti Kero2, Noora Partamies4,
Pekka T Verronen3, Jyrki Manninen2, Ilkka Virtanen2, Tero Raita2
1.名古屋大学宇宙地球環境研究所、2.オウル大学、3.フィンランド気象研究所、4.UNIS
1.Institute for Space-Earth Environmental Research, Nagoya University, 2.University of Oulu,
3.Finnish Meteorological Institute, 4.The University Centre in Svalbard
In recent years, variations of the atmospheric minor component (NOx, HOx, O3, etc) due to energetic
electron precipitation (EEP) have been widely studied by many researchers. There are several
sources to cause EEP, such as solar proton event, electron precipitation during pulsating aurora,
and relativistic electron precipitation. This study focuses on pulsating-auroral (PA-) EEP, which
is an almost daily occurrence in the morning sector of the auroral ionosphere. EISCAT measurements
and GEMSIS-RBW simulation reveal that energy range of the PA-EEP is higher than 10 keV to a few
hundred keV [Saito et al., 2012; Miyoshi et al., 2015]. Such energetic electrons can cause
ionization in the mesosphere and upper stratosphere, resulting in forced modifications in thechemical equilibrium of the atmospheric minor components. This process is essentially important forunderstanding solar-climate relationships.
Japanese and Finnish researchers organize an international joint team, and conduct observation
campaigns with the EISCAT radars, optical instruments, KAIRA riometer, and VAPs satellites in orderto understand generation mechanism of PA-EEP and its impact on the ionosphere and atmosphere.
Additionally we will analyze the archived data sets to understand EEP features. These scientificobjectives will be accomplished by collaborations with the GEMSIS-RBW model and Sodankyla Ion
Chemistry (SIC) model. In this presentation we will introduce some case studies of measurements andmodel calculations.
[References]
Miyoshi, Y., S. Oyama, S. Saito et al., Energetic electron precipitation associated with pulsating
aurora EISCAT and Van Allen Probes observations, J. Geophys. Res., 2015.
Saito, S., Y. Miyoshi, and K. Seki, Relativistic electron microbursts associated with whistler
chorus rising tone elements: GEMSIS-RBW simulations, Journal of Geophysical Research, 2012.
キーワード：脈動オーロラ、大気微量成分
Keywords: pulsating aurora, atmospheric minor component©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-19 -PEM04-20

日本地球惑星科学連合2016年大会

Exploring Predictive Performance of Ground dB/dt Models: A Reanalysis of the Geospace
Model Transition Challenge*Daniel T Welling1, Brian J Anderson2, Geoff Crowley3, Antti Pulkinnen4, Lutz Rastaetter4
1.University of Michigan Ann Arbor, 2.John Hopkins Applied Physics Laboratory, 3.Atmospheric &Space Technology Research Associates, LLC, 4.NASA Goddard Space Flight Center
Geomagnetically Induced Currents (GICs) are electric currents driven by activity in near-Earthouter space as our magnetic field interacts with that of the Sun’s. These currents can flow throughany conducting path, including pipelines and high voltage electric power lines. When GICs become
strong enough, these technological systems can be interrupted or damaged, drastically affecting
those who depend on them. Developing systems to accurately monitor and predict GIC events has
therefore become a critical task for national security. An initial effort to assess the performanceof five operationally-promising GIC models was presented by Pulkkinen et al. [2013]. The resultsof this validation effort showed that the models can provide predictive value, but shortcomings
exist. While this work represents a landmark first-step towards numerical space weather
forecasting, many questions remain concerning each of the models’ capabilities. How do the models
perform for different levels of geomagnetic activity? What is the range of activity for which themodels have been validated? Based on the assumptions and input data for each model, what is the
maximum driving for which the results can be considered valid?
This study presents a reanalysis of the Pulkkinen et al. [2013] results to extend our understandingof the models’ capabilities and answer the questions posed above. Data-model errors between
predicted and observed magnetometer dB/dt values are binned by activity (solar wind electric fieldor DST). The bins are arranged to yield error as a function of driving. Input data for empirical
relationships, on which the models either rely or of which they comprise entirely, are binned by
activity to determine the range of conditions over which each model is valid. A comparison of eachmodel is presented to further illustrate previously published results. Additionally, because GICs
are intimately linked to the electrojets which are in turn closely related to field-aligned
currents, we also compare Birkeland currents from the different models to observations. For this we
use radial current distributions from AMPERE based on the Iridium satellite constellation,
providing assessments of the intensities and distributions of the global scale currents every ten
minutes. From this new analysis, we place error bars on recent predictions of dB/dt made by theSpace Weather Modeling Framework.
Keywords: Geomagnetically Induced Currents, Space Weather Modeling©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-20 -PEM04-21

日本地球惑星科学連合2016年大会

サブストームのシミュレーション：電流系とオーロラ構造
Substorm simulation: Current system and auroral structure*海老原 祐輔1、田中 高史2*Yusuke Ebihara1, Takashi Tanaka2
1.京都大学生存圏研究所、2.九州大学 国際宇宙天気科学・教育センター
1.Research Institute for Sustainable Humanosphere, Kyoto University, 2.International Center forSpace Weather Science, Kyushu University
Substorm is known to cause strong geomagnetically induced current (GIC) on the ground in the polar
region. The GIC is primarily caused by the ionospheric current that is intensified by field-aligned
current (FAC) during the substorm. On the basis of the result obtained by a global
magnetohydrodynamic (MHD) simulation, we propose a scenario for the evolution of the current systemassociated with a substorm expansion. (1) Near-Earth neutral line releases magnetic tension in thenear-Earth plasma sheet to compress plasma and accelerate it earthward. (2) Earthward,
perpendicular flow is converted to parallel flow when flow braking takes place. (3) Plasma moves
earthward parallel to a field line. The plasma pressure is additionally enhanced at off-equator.
(4) Flow vorticities coexist near the off-equatorial high-pressure region. Resultant FAC isconnected to the ionosphere, which may manifest initial brightening of aurora. The ionosphericcurrent starts to increase. (5) Due to continued earthward flow, the high-plasma pressure region
continues to expand to the east and west. (6) The ionospheric conductivity continues to increase in
the upward FAC region, and the conductivity gradient becomes steeper. (7) The convergence of theHall current gives rise to divergent electric field near the steep gradient of the conductivity.
(8) Due to the divergent electric field, magnetospheric plasma moves counterclockwise at low
altitude (as seen in the Northern Hemisphere). (9) The additional flow vorticity generates a
localized upward FAC at low altitudes, which may manifest westward traveling surge (WTS) of aurora.
As a consequence, the ionospheric current, conductivity, and the magnetospheric current system areredistributed. The evolution of the substorm depends on the solar wind condition as well as themagnetospheric condition. We will discuss the optimal condition that potentially causes the strong
substorm.
キーワード：サブストーム、オーロラ、地磁気誘導電流(GIC)
Keywords: Substorm, Aurora, Geomagnetically Induced Current (GIC)©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-21 -PEM04-22

日本地球惑星科学連合2016年大会

SuperDARNレーダーデータを用いた太陽フレア・粒子降り込みによる電離圏電子密度変動の同定
Identification of ionospheric plasma density changes due to solar flares and energetic
particle precipitation using the SuperDARN radar data
*西谷 望1、堀 智昭1、行松 彰2、長妻 努3*Nozomu Nishitani1, Tomoaki Hori1, Akira Sessai Yukimatu2, Tsutomu Nagatsuma3
1.名古屋大学宇宙地球環境研究所、2.国立極地研究所、3.情報通信研究機構
1.Institute for Space-Earth Environmental Research, Nagoya University, 2.National Institute ofPolar Research, 3.National Institute of Information and Communications Technology
Watanabe and Nishitani (Adv. Polar Sci, 2013) showed that during solar flares the SuperDARN data
show positive Doppler velocities in ground / sea scatter echoes, and that this velocity change canbe interpreted mainly in terms of the abnormal ionization of the D-region ionosphere due to EUV /X-ray, leading to the shortening of the HF ray paths. They also showed that it is possible toidentify the plasma density changes from the Doppler velocity distributions. These result suggeststhat it might be possible to identify the D-region plasma density changes due to energetic particle
precipitation events such as substorms using the same technique.
Ionospheric convection around substorm expansion onset are characterized by reduction of sheared
flow and enhancement of equatorward flows (e.g., Bristow et al., J. Geophys. Res., 2007). However,there have been no studies on the effect of D-region HF wave absorption due to particle
precipitation, which could lead to positive Doppler shift, which is independent of beam number but
could be positively (negatively) correlated with the range (elevation angle) Initial result of thequantitative estimation of Doppler velocities associated with particle precipitation will bepresented.
キーワード：SuperDARNレーダー、電離圏電子密度変動、太陽フレア・粒子降り込み
Keywords: SuperDARN radars, ionospheric plasma density change, solar flare / energetic particle
precipitation©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-22 -PEM04-23

日本地球惑星科学連合2016年大会

Total electron content forecast model over Japan using a machinelearning technique
Total electron content forecast model over Japan using a machinelearning technique*西岡 未知1、丸山 隆1、津川 卓也1、陣 英克1、石井 守1*Michi Nishioka1, Takashi Maruyama1, Takuya Tsugawa1, Hidekatsu Jin1, Mamoru Ishii1
1.（独）情報通信研究機構
1.National Institute of Information and Communications Technology
Forecasting ionospheric condition is important for space weather operation, especially forpredicting propagation delay of the radio waves in the ionosphere. National Institute ofInformation and Communications Technology (NICT), Japan, develops an ionospheric forecasting systemof total electron content (TEC) in addition to a TEC monitoring system. Although several empiricaland theoretical models have been developed in a decade, no model is available for forecasting TEC
over Japan. Our purpose is to accomplish an operational TEC model over Japan using an artificial
neural network technique which is developed by Maruyama [2007]. In our model, absolute TEC values
for each day over Japan were projected on a two-dimension TEC map, that is, a local-time andlatitudinal map. Then the time-latitudinal variation was fitted by using the surface harmonic
function. The coefficients of the expansions were modeled by using a neural network technique. For
the learning process, we used absolute TEC value from 1997 to 2014. The input parameters areproxies of the season, the solar activity, and the geomagnetic activity. Thus, daily
two-dimensional TEC maps can be obtained for any days when the input parameters are available. We
used input parameters which are provided in real-time by some institutes and achieved one-day TEC
prediction over Japan.
キーワード：machine learning、total electron content、TEC forecast
Keywords: machine learning, total electron content, TEC forecast©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-23 -PEM04-24

日本地球惑星科学連合2016年大会

GPS phase scintillation during the geomagnetic storm of March 17, 2015: The relation toauroral electrojet currents*Paul Prikryl1,2, Reza Ghoddousi-Fard3, Martin Connors4, James M. Weygand5, Donald W. Danskin2, P.
Thayyil Jayachandran1, Knut Stanley Jacobsen6, Yngvild Linnea Andalsvik6, Evan G. Thomas7, Mike
Ruohoniemi7, Tibor Durgonics8, Kjellmar Oksavik9,10, Yongliang Zhang11, Marcio Aquino12, V. Sreeja12
1.Physics Dept., University of New Brunswick, Fredericton, NB, Canada, 2.Geomagnetic Laboratory,
Natural Resources Canada, Ottawa, ON, Canada, 3.Canadian Geodetic Survey, Natural Resources Canada,
Ottawa, ON, Canada, 4.Athabasca University, Edmonton, AB, Canada, 5.Institute of Geophysics andPlanetary Physics, University of California, Los Angeles, CA, USA, 6.Norwegian Mapping Authority,
Hønefoss, Norway, 7.Bradley Dept. of Electrical and Computer Engineering, Virginia Tech,Blacksburg, VA, USA, 8.Technical University of Denmark, National Space Institute, Kongens Lyngby,
Denmark, 9.Birkeland Centre for Space Science, Dept. of Physics and Technology, Univ. of Bergen,
Bergen, Norway, 10.The University Centre in Svalbard, Longyearbyen, Norway, 11.Johns Hopkins
University Applied Physics Laboratory, Laurel, MD, USA, 12.Nottingham Geospatial Institute,
University of Nottingham, Nottingham, UK
Ionospheric irregularities cause rapid fluctuations of radio wave amplitude and phase that candegrade GPS positional accuracy and affect performance of radio communication and navigation
systems. The ionosphere becomes particularly disturbed during geomagnetic storms caused by impacts
of coronal mass ejections compounded by high-speed plasma streams from coronal holes. Geomagnetic
storm of March 17, 2015 was the largest in the current solar cycle. The high-latitude ionosphere
dynamics is studied using arrays of ground-based instruments including Global Navigation Satellite
System (GNSS) receivers, HF radars, ionosondes, riometers and magnetometers. GPS phase
scintillation index is computed for L1 signal sampled at the rate of up to 100 Hz by specialized
GNSS scintillation receivers of the Expanded Canadian High Arctic Ionospheric Network (ECHAIN) andthe Norwegian Mapping Authority network supplemented by additional GNSS receivers operated by otherinstitutions. To further extend the geographic coverage, the phase scintillation proxy index is
obtained from geodetic-quality GPS data sampled at 1 Hz. In the context of solar wind coupling to
the magnetosphere-ionosphere system, it has been demonstrated that GPS phase scintillation is
primarily enhanced in the cusp, tongue of ionization (TOI) broken into patches drawn into the polar
cap from the dayside storm-enhanced plasma density (SED) and in the auroral oval during energetic
particle precipitation events, substorms and pseudo-breakups in particular. In this paper we
examine the relation to auroral electrojet currents observed by arrays of ground-basedmagnetometers and energetic particle precipitation observed by DMSP satellites. Equivalentionospheric currents (EICs) are obtained from ground magnetometer data using the sphericalelementary currents systems (SECS) technique developed by Amm and Viljanen (1999) that has been
applied over the entire North American ground magnetometer network by Weygand et al. (2011).
References:Amm, O., and A. Viljanen, Earth Planets Space, 51, 431–440, 1999.
Weygand et al., J. Geophys. Res., 116, A03305, 2011.
Keywords: Polar and auroral ionosphere (Ionospheric irregularities, Ionospheric currents, Energetic
particles), Radio science (Radio wave propagation, Space and satellite communication),Space weather (Impacts on technological systems)©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-24 -PEM04-25

日本地球惑星科学連合2016年大会

TIE-GCMモデルと地上GPS-TEC観測による磁気嵐時の電離層データ同化
Ionospheric data assimilation with TIE-GCM and GPS-TEC during geomagnetic storm period*陳 佳宏1、Lin Charles1、Matsuo Tomoko3,4、Chen Wei-han1、Lee I. T.2、劉 正彦5,6、林 佳廷1*Chia-Hung Chen1, Charles Lin1, Tomoko Matsuo3,4, Wei-han Chen1, I. T. Lee2, Jann-Yenq Liu5,6,
Jia-Ting Lin1
1.台湾国立成功大学地球科学学科、2.台湾気象庁、3.アメリカコロラド大学環境科学、4.アメリカ宇宙天気セ
ンター、5.台湾国立中央大学太空科学学科、6.台湾国立中央大学リモートセンシングセンター
1.Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan, 2.Central Weather
Bureau, Taipei, Taiwan, 3.Cooperative Institute for Research in Environmental Sciences, Universityof Colorado Boulder, Boulder, Colorado, USA, 4.Space Weather Prediction Center, National Oceanicand Atmospheric Administration, Boulder, Colorado, USA, 5.Institute of Space Science, National
Central University, Chung-Li, Taiwan, 6.Center for Space and Remote Sensing Research, National
Central University, Chung-Li, Taiwan
The main purpose of this study is to investigate the latency time for the ionosphere data
assimilation during the geomagnetic storm. An Ensemble Kalman Filter (EnKF) module developed by
National Center for Atmospheric Research (NCAR), called as Data Assimilation Research Testbed(DART), is applied to assimilate the ionospheric electron density into a theoretical model(Thermosphere-Ionosphere-Electrodynamics General Circulation Model, TIE-GCM) with ground-based GPS
total electron content (TEC) observations during the 26 September 2011 geomagnetic storm period.
Effects of various assimilation time intervals, 60-, 30-, and 10-minute, on the ionosphericforecast responses are examined by their global root-mean-square errors (RMSEs) during the entire
storm period. Substantial reduction of RMSEs for 10 minutes assimilation cycle suggests theionospheric data assimilation system greatly improve the capability of model forecast during thegeomagnetic storm period. Further examination shows that the neutral state variables in theassimilation model are the important factor to change the trajectory of model forecasting. However,
the assimilation model with neutral state variables still needs the shorter assimilation cycle(10-minute in this study) to restrain overfitting of neutrals and lead to higher forecast accuracy
during the geomagnetic storm.
キーワード：電離層データ同化、磁気嵐
Keywords: Ionospheric data assimilation, geomagnetic storm©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-25 -PEM04-26

日本地球惑星科学連合2016年大会

大気圏電離圏結合モデルGAIAの高精度化およびデータ同化に向けた取り組み
Development of a whole atmosphere-ionosphere model GAIA for higher accuracy and its
application toward data assimilation modeling*陣 英克1、三好 勉信2、藤原 均3、品川 裕之1、垰 千尋1*Hidekatsu Jin1, Yasunobu Miyoshi2, Hitoshi Fujiwara3, Hiroyuki Shinagawa1, Chihiro Tao1
1.情報通信研究機構、2.九州大学、3.成蹊大学
1.National Institude of Information and Communications Technology, 2.Kyushu University, 3.Seikei
University
超高層大気領域は人工衛星や地上‐衛星間をつなぐ電波の通り道であり、その擾乱や変動は衛星の軌道や姿
勢、また電波の伝搬に影響する。超高層大気の擾乱や変動の起源は、太陽フレアなど太陽面の活動が磁気圏を通して入ってくるだけではなく、地表付近の気象の影響も中層大気を通り入ってくることが知られてきた。我々は、電離圏・熱圏の全球分布を将来的に数値的に推測・予測するために、地表から熱圏上部までの中性大気領域と電離圏領域を相互に結合する大気圏電離圏結合モデル（GAIA）を開発してきた。しかし、長期シ
ミュレーションと電離圏・熱圏の観測などとの比較・検証を行ったところ、数値予測への応用や大気研究により有効利用するためには、モデルの高精度化を進める必要があると分った。
本発表では、モデル高精度化の一環として、電離圏のダイナミクスやエネルギーの扱いの改良や、高分解能化などの試みとその結果について紹介する。また、数値予測に向けてデータ同化に対するインターフェースを開発しており、今後のデータ同化への取り組みについて紹介する。
キーワード：電離圏、熱圏、シミュレーション、モデリング、データ同化
Keywords: ionosphere, thermosphere, simulation, modeling, data assimilation©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-26 -PEM04-27

日本地球惑星科学連合2016年大会

実時間データ同化にもとづくオーロラ活動指数の予測
SUSANOO-Aurora Activity Forecast: Forecast of the aurora index with the real time data
assimilation*三好 由純1、山本 凌大1、上野 玄太2、塩田 大幸1、能勢 正仁3、町田 忍1*Yoshizumi Miyoshi1, Ryota Yamamoto1, Genta Ueno2, Daikou Shiota1, Masahito Nose3, Shinobu Machida1
1.名古屋大学宇宙地球環境研究所、2.統計数理研究所、3.京都大学大学院理学研究科附属地磁気世界資料解析センター
1.Institute for Space-Earth Environmental Research, Nagoya University, 2.The Institute of
Statistical Mathematics, 3.Data Analysis Center for Geomagnetism and Space Magnetism Graduate
School of Science, Kyoto University
The AU/AL indices are a manifest of the global aurora activity, and their forecast is useful torecognize the future evolution of geospace. In order to forecast the aurora activity, we havedeveloped the forecast system of the aurora index based on the prediction model of Goertz etal.(1992). The model calculates the time evolution of the aurora index using the solar windelectric fields. The real time space weather forecast system SUSANOO (Shiota et al., 2014,
http://st4a.stelab.nagoya-u.ac.jp/susanoo/) has provided the next 7 days solar wind parameters at 1
AU, and we calculate the time variations of the aurora indices using the electric fields from theSUSANOO-solar wind simulation. The Goertz model includes several empirical parameters, and theforecast skill depends on the accuracy of these parameters. We have implemented the real-time data
assimilation to improve these parameters by comparing the model results and the actual aurora
index. The developed system consists of the hindcast and forecast stages. In the hindcast stage,
prediction, smoothing and filtering in the data assimilation are performed for the previous 7 days
using the data from the SUSANOO-solar wind simulation and the observed aurora index, which improves
the parameters for the model. Using the estimated parameters from the hindcast stage, we calculate
the time evolution of the aurora index for the next 7 days as the forecast stage. In thispresentation, we will present the concept of SUSANOO-aurora activity forecast and initial resultsfrom test-operations.
キーワード：データ同化、予測、オーロラ活動指数
Keywords: Data assimilation, Forecast, Auroral activity index©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-27 -PEM04-28

日本地球惑星科学連合2016年大会

NICTの新太陽電波望遠鏡と宇宙天気予報New solar radio telescope of NICT and its space weather forecasting*岩井 一正1、久保 勇樹1、石橋 弘光1、亘 慎一1、石井 守1*Kazumasa Iwai1, Yuki Kubo1, Hiromitsu Ishibashi1, Shinichi Watari1, Mamoru Ishii1
1.情報通信研究機構
1.National Institute of Information and Communications Technology
太陽ではフレアに代表される爆発現象が絶えず起きている。この爆発現象に伴い、高エネルギー粒子(SEP)や、コロナ質量放出現象(CME)が発生する。これらの一部は地球にも到来し、人工衛星の運用や電波通信に大きな影響を与えることがある。太陽の爆発現象では突発的な電波が放射される(太陽電波バースト)。電波
は粒子よりも早く伝搬するため、太陽電波バーストを定常的に観測することは、宇宙天気の予報にとって極めて有効である。
NICTでは太陽活動を監視することを目的に茨城県平磯にて太陽の電波観測を行ってきた。今回、より高性能な
太陽電波の広帯域分光観測を目指し、観測場所をNICTの山川電波観測施設(鹿児島県指宿市)に移転するとともに、新しい太陽電波望遠鏡の開発を行った。本望遠鏡は、口径8メートルのパラボラアンテナからなる。太陽電波バーストはメートル波からマイクロ波にかけて発生する広帯域の連続波放射である。本望遠鏡は焦点に2種類の広帯域アンテナを用いることで、0.07GHzから9.0GHzまでを1台のアンテナでカバーしている。太陽の視直径は約0.5度あり、太陽フレアはどこで発生するか事前の予報が難しいため、望遠鏡は太陽全面の視野を持つ必要がある。そこで高周波側のアンテナ位置をデフォーカスすることで、観測する全帯域で太陽全面の視野を確保した。受信信号は受信機内で分割され、FPGAを用いたデジタル分光計に供給される。本望遠鏡に開発されたデジタル分光計は、帯域幅2GHz・分光点数4096点と、帯域幅1GHz・分光点数32768点の2種類があり、合計10台で9GHzの帯域幅の両円偏波同時観測を実現した。分光計はデッドタイム無く連続的に分光可能で、スペクトルは内部で積算され、8ms毎に積算スペクトルを記録することで、高時間分解観測を可能とした。本装置の広帯域な感度特性は、様々な周波数で発生する電波バーストの観測に有効であり、宇宙天気現象の検出精度向上に大いに活用できること考えられる。また、本装置の高分解なスペクトルデータは、太陽電波バーストに含まれる微細なスペクトル構造を分解可能であり、フレアにおける非熱的粒子の生成過程の解明につながる成果も期待される。
キーワード：太陽、太陽電波バースト、宇宙天気予報、太陽高エネルギー粒子、電波観測
Keywords: Sun, solar rasio burst, space weather forecasting, solar energetic particle, radio
observation©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-28 -PEM04-29

日本地球惑星科学連合2016年大会

Cross-field superslow propagation by phase-mixing of Alfven/slow mode waves in solar
coronaCross-field superslow propagation by phase-mixing of Alfven/slow mode waves in solar
corona*金子 岳史1、Goossens Marcel2、Soler Roberto3、Terradas Jaume3、Van Doorsselaere Tom2、横山 央明1、Wright Andrew4*Takafumi Kaneko1, Marcel Goossens2, Roberto Soler3, Jaume Terradas3, Tom Van Doorsselaere2, Takaaki
Yokoyama1, Andrew Nicholas Wright4
1.東京大学大学院理学系研究科地球惑星科学専攻、2.Centre for Mathematical Plasma Astrophysics,
Katholieke Universiteit Leuven、3.Departament de Física, Universitat de les Illes Balears、4.Schoolof Mathematics and Statistics, University of St Andrews
1.Graduate School of Science,The University of Tokyo,Department of Earth and Planetary Science,
2.Centre for Mathematical Plasma Astrophysics, Katholieke Universiteit Leuven, 3.Departament de Física, Universitat de les Illes Balears, 4.School of Mathematics and Statistics, University of St
Andrews
We discuss the apparent cross-field propagation by phase mixing of continuum Alfven waves orcontinuum slow mode waves in the solar coronal magnetic structures.
Recent observations and numerical simulations for coronal waves have found waves propagating acrossmagnetic field lines at rather slow speed. Although only fast mode waves can propagate acrossmagnetic field lines, the observed propagation speed is much slower than the typical fast mode
speed. Hence it has been difficult to understand the nature of this cross-field ‘superslow’
propagation. We show that the phase-mixing of continuum Alfven or slow mode waves can explain thisphenomenon. Phase-mixing of continuum Alfven or slow mode waves produces phase velocities
perpendicular to magnetic field that decrease with time. Hence phase mixing can produce across-field superslow propagation after a sufficient lapse of time. We show that the analyticalsolutions of apparent wavelength and phase speed of phase-mixing quantitatively explain the
superslow waves in the results of numerical simulation. We also show the existence of superslow
waves in coronal potential arcades and discuss the applicability of our results to coronal
seismology.
キーワード：太陽コロナ、太陽プロミネンス/フィラメント、磁気流体波動
Keywords: Solar corona, Solar prominence/filament, MHD wavess©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-29 -PEM04-30

日本地球惑星科学連合2016年大会

Magnetohydrodynamic simulation of interplanetary propagation of multiple coronalmassejections with internalmagnetic flux rope (SUSANOO-CME)
Magnetohydrodynamic simulation of interplanetary propagation of multiple coronalmassejections with internalmagnetic flux rope (SUSANOO-CME)*塩田 大幸1、片岡 龍峰2,3*Daikou Shiota1, Ryuho Kataoka2,3
1.名古屋大学 宇宙地球環境研究所、2.国立極地研究所、3.総合研究大学院大学
1.Institute for Space and Earth Environmental Research, Nagoya University, 2.National institute for
Polar research, 3.SOKENDAI
Coronal mass ejections (CMEs) are the most important drivers of various types of space weather
disturbance. Here we report a newly developed magnetohydrodynamic (MHD) simulation of the solar
wind, including a series of multiple CMEs with internal spheromak-type magnetic fields. First, thepolarity of the spheromak magnetic field is set as determined automatically according to theHale-Nicholson law and the chirality law of Bothmer and Schwenn. The MHD simulation is therefore
capable of predicting the time profile of the southward interplanetary magnetic field at the Earth,in relation to the passage of a magnetic cloud within a CME. This profile is the most importantparameter for space weather forecasts of magnetic storms. In order to evaluate the current abilityof our simulation, we demonstrate a test case: the propagation and interaction process of multiple
CMEs associated with the highly complex active region NOAA 10486 in October to November 2003, andpresent the result of a simulation of the solar wind parameters at the Earth during the 2003
Halloween storms. We succeeded in reproducing the arrival at the Earth’s position of a large amountof southward magnetic flux, which is capable of causing an intense magnetic storm. We find that theobserved complex time profile of the solar wind parameters at the Earth could be reasonably wellunderstood by the interaction of a few specific CMEs.
キーワード：コロナ質量放出、太陽風、MHD
Keywords: CME, solar wind, MHD©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-30 -PEM04-31

日本地球惑星科学連合2016年大会

適合格子細分化法を用いた太陽園の動的モデルの構築
A dynamical model of the heliosphere with the adaptive mesh refinement*松本 倫明1、片岡 龍峰2、塩田 大幸3、宮原 ひろ子4、三宅 晶子5*Tomoaki Matsumoto1, Ryuho Kataoka2, Daikou Shiota3, Hiroko Miyahara4, Shoko Miyake5
1.法政大学、2.国立極地研究所、3.名古屋大学、4.武蔵野美術大学、5.茨城工業高等専門学校
1.Hosei University, 2.National Institute of Polar Research, 3.Nagoya University, 4.Musashino Art
University, 5.National Institute of Technology, Ibaraki College
A change in the heliospheric environment plays an important role in the modulation of the galactic
cosmic rays; the magnetic field structure and the speed of the solar wind affect the cosmic raytransport in the heliosphere. Since the heliospheric environment is affected by the solar wind
activities, we have been developing a framework for simulating the heliosphere by using MHD
simulations.
The simulation code is based on SFUMATO code (Matsumoto 2007), which employs the block-structured
adaptive mesh refinement (AMR) technique. The solar wind model gives the inner boundary conditionof the simulations, and it is based on the model of Kataoka et al. (2009) and Shiota et al. (2014).
The solar wind model adopted here is reconstructed by the observation of the solar magnetic fields.
At this moment, the refinement criterion of AMR grid is only a function of the distance from theSun. Our model reproduces the Parker spiral owing to the solar rotation.
We also measured the performance of the simulation code for massively parallel calculations. In thecase of 1024/2048 cores calculations, our code exhibits parallel ratios of 99.945-99.982% andparallel efficiencies of 73.4-86.4%, depending on the implementation of a refinement manner. Such ahigh scalability is demonstrated even by a flat MPI parallelization.
キーワード：太陽圏、太陽風、MHD
Keywords: heliosphere, solar wind, MHD©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-31 -PEM04-32

日本地球惑星科学連合2016年大会

伊勢スギの酸素同位体比分析から明らかになった小氷期末期の降水量増加
A humid climate of the last stage of the Little Ice Age in central Japan reconstructedusing oxygen isotopes from tree-ring*坂下 渉1、宮原 ひろ子2、横山 祐典1、中塚 武3、阿瀬 貴博1、星野 安治4、大山 幹成5、米延 仁志6、竹村
恵二7*Wataru Sakashita1, Hiroko Miyahara2, Yusuke Yokoyama1, Takeshi Nakatsuka3, Takahiro AZE1, Yasuharu
Hoshino4, Motonari Ohyama5, Hitoshi Yonenobu6, Keiji Takemura7
1.東京大学 大気海洋研究所、2.武蔵野美術大学造形学部、3.総合地球環境学研究所、4.奈良文化財研究所、5.東北大学学術資源研究公開センター植物園、6.鳴門教育大学大学院学校教育研究科、7.京都大学大学院
理学研究科附属地球熱学研究施設
1.Atmosphere and Ocean Research Institute, The University of Tokyo, 2.College of Art and Design,Musashino Art University, 3.Research Institute for Humanity and Nature, 4.National ResearchInstitute for Cultural Properties, Nara, 5.The Center for Academic Resources and Archives,
Botanical Gardens, Tohoku University, 6.Graduate School of Education, Naruto University of
Education , 7.Beppu Geothermal Researh Laboratory, Institute for Geothermal Sciences, Graduate
School of Science, Kyoto University
The Asian monsoon is an important part of the Earth’s climate system that is characterized byvariations in the strength and expansion of the summer rain band. Rainfall reconstructions in China
have revealed changing patterns of rainfall during the Little Ice Age (LIA), but few hydroclimate
reconstructions around Japan have hindered the understanding of physical processes associated withthe atmospheric system in the western North Pacific. Here, we report on rainfall variations in the
Meiyu/Baiu season from AD 1600–1959 by using tree-ring cellulose oxygen isotopes from central
Japan; this is the longest record in the eastern most regions under the monsoon’s influence. Datasuggest that the wettest period occurred around AD 1790–1860, the final stage of the LIA. This
shift was concurrent with sea surface temperature anomalies around the Philippines and off easternJapan. Thus, meridional atmospheric circulation was likely weak during the last stage of the LIA.
キーワード：小氷期、モンスーン、樹木年輪、酸素同位体比
Keywords: Little Ice Age, Monsoon, tree-ring, oxygen isotopes©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-32 -PEM04-33

日本地球惑星科学連合2016年大会

台風の発生と太陽活動の関係
Relationship between typhoon occurrence and solar activity*高橋 幸弘1、佐藤 光輝1、山下 幸三2*Yukihiro Takahashi1, Mitsuteru Sato1, Kozo Yamashita2
1.北海道大学・大学院理学院・宇宙理学専攻、2.サレジオ工業高等専門学校
1.Department of Cosmosciences, Graduate School of Science, Hokkaido University, 2.Salesian
Polytechnic
It has been pointed out that atmospheric activity has ~27-day periodicity, which implies theconnections between solar activity and the earth’s climate since the rotation period of the sunnear its equator is 27 days. We have showed a close relationship between globally synchronized
thunderstorm/cloud activities in the tropical latitudinal range and solar parameter with ~one-month
periodicity for a certain half year, using lightning data, a proxy of thunderstorm activity,
obtained by the global radio wave network and a proxy of cloud amount, Outgoing Longwave Radiation(OLR). It was reported that the thunderstorm activity in Asia Maritime Continent (AMC) shows aseesaw correlation with the cloud in Western Pacific Warm Pool (WPWP), which show strong
correlation with intensity of cosmic ray without time lag. It was revealed that this cloudincreases in WPWP correspond to typhoon occurrences. Here we found a strong similarity andsynchronization between the variation of lightning activity in AMC and that of the averaged OLR in
broad longitudinal range in equatorial region (280E - 110E, 10S - 10N), where very limited numbersof typhoons take place. Moreover, all these parameters apparently show a clear correlation withsolar parameters, such as galactic cosmic rays or F10.7 for the one-month periodicity. This factsuggests further and extensive studies, involving scientists in broader research fields, are needed
to understand the global climate.
キーワード：台風、太陽活動、27日周期、積乱雲、西太平洋暖水プール
Keywords: typhoon, solar activity, 27-day, thunderstorm, WPWP

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-33 -PEM04-P01

日本地球惑星科学連合2016年大会

太陽風磁気ロープ発生頻度と太陽活動サイクルに関する検討
A critical review on solar cycle variation of interplanetary magnetic flux ropes*丸橋 克英1*Katsuhide Marubashi1
1.アジア宇宙環境研究機構
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.
キーワード：solar wind、interplanetary magnetic flux rope
Keywords: coronal mass ejection, solar-cycle variation©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P01 -PEM04-P02

日本地球惑星科学連合2016年大会

太陽磁気フラックスロープを生む4重極活動領域の形成
Formation of a Quadrupolar Active Region Producing a Magnetic Flux Rope
*大井 喜智1、横山 央明1、鳥海 森2*Yoshiaki Oi1, Takaaki Yokoyama1, Shin Toriumi2
1.東京大学大学院理学系研究科地球惑星科学専攻、2.国立天文台
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.
キーワード：太陽、フレア、黒点
Keywords: Sun, Flares, Sunspots©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P02 -PEM04-P03

日本地球惑星科学連合2016年大会

フォースフリー磁場モデリングを用いた四重極磁場構造におけるホモロガスフレアの研究
Studies on homologous flares at quadrupole magnetic field using force-free field modeling*川畑 佑典1,3、井上 諭2、清水 敏文3,1*Yusuke Kawabata1,3, Satoshi Inoue2, Toshifumi Shimizu3,1
1.東京大学大学院理学系研究科地球惑星科学専攻、2.マックスプランク太陽系研究所 、3.宇宙航空研究開発機
構宇宙科学研究所
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.
キーワード：太陽フレア、磁気リコネクション©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P03 -PEM04-P03

日本地球惑星科学連合2016年大会

Keywords: Solar flare, Magnetic reconnection©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P03 -PEM04-P04

日本地球惑星科学連合2016年大会

太陽コロナにおけるダブルアーク不安定性
Double Arc Instability in the solar corona*石黒 直行1、草野 完也1,2*Naoyuki Ishiguro1, Kanya Kusano1,2
1.名古屋大学 宇宙地球環境研究所、2.国立研究開発法人 海洋研究開発機構
1.Institute for Space-Earth Environmental Research, Nagoya University, 2.Japan Agency for
Marine-Earth Science and Technology
太陽コロナにおけるフラックスロープの安定性は、太陽フレアやコロナ質量放出（CME）といった宇宙天気擾乱
の主たる原因となる現象の発生に関連している。近年、太陽面爆発現象の原因としてトーラス不安定性がKliem& Toeroek (2006)によって提案された。しかしながら、いかにして不安定性が駆動されるのかについてはよくわかっていない。その一方で、不安定なフラックスロープを生じさせる過程のシナリオとして有名なものの一
つに、Moore et al. (2001)で提案されたテザーカッティングリコネクションがある。このシナリオは強くシア
した磁力線間の磁気リコネクションがダブルアーク型ループを形成し、やがて爆発現象が生じることを提案している。しかしながら、この初期段階の際に見られるダブルアーク型ループの安定性は未だに解析されていない。
本研究の目的は、ダブルアーク型電流ループの安定性を理論的に解析することである。そのため、ダブル
アーク型電流ループをお互いに結合した二つの円形トーラスでモデル化し、その安定性を数値的に計算した。その結果TIとは対照的に、ダブルアーク型電流ループは一様な外部磁場の元でも不安定化しうることを見出した。この結果はダブルアーク型電流ループに対する不安定性、すなわちダブルアーク不安定性（DAI）は
TIとは異なるものであることを示している。またTIの臨界の基準として用いられるdecay indexはDAIには適用できず、さらにDAIの必要条件は磁力線の半回転以上のねじれであることが分かった。DAI後の成長はフラック
スロープの爆発の観測結果ともよく一致している。これらの結果は、テザーカッティングリコネクションに基
づくDAIは実際に爆発現象のもとで機能し、どのように爆発現象が駆動されるのかよく説明しうる、ということを示している。
キーワード：太陽、太陽フレア、不安定性
Keywords: Sun, solar flare, instability©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P04 -PEM04-P05

日本地球惑星科学連合2016年大会

国際コンソーシアムによる野辺山電波ヘリオグラフの科学運用
Continued Operation of Nobeyama Radioheliograph by the International Consortium (ICCON)*増田 智1、柴崎 清登1,2、Gopalswamy Nat3、Yan Yihua4、Cho Kyung-Suk5*Satoshi Masuda1, Kiyoto Shibasaki1,2, Nat Gopalswamy3, Yihua Yan4, Kyung-Suk Cho5
1.名古屋大学宇宙地球環境研究所、2.太陽物理学研究所、3.Goddard Space Flight Center, NASA、4.National
Astronomical Observatories, Chinese Academy of Sciences、5.Korea Astronomy and Space Science
Institute
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.
キーワード：太陽、電波
Keywords: Sun, radio©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P05 -PEM04-P06

日本地球惑星科学連合2016年大会

太陽磁場観測による自転速度算出とその長期変動について
Calculation of solar rotation rate using the magnetic field observation, and its long-term
variation*藤山 雅士1、今田 晋亮1、町田 忍1*Masashi Fujiyama1, Shinsuke Imada1, Shinobu Machida1
1.名古屋大学宇宙地球環境研究所
1.Institute for Space-Earth Environmental Research
太陽から放出されるプラズマ（太陽風）により地球周辺の宇宙環境は影響を受け続けている。太陽から放出されるプラズマはフレアやCMEなどの現象により、爆発的に放出され、地球及び人工衛星に甚大な被害を及ぼす。これを太陽嵐と呼ぶ。また、太陽風の変動全体を宇宙天気と呼び、それを正しく予測するための研究が様々な角度から行われている。太陽地球環境予測研究のひとつに太陽の活動メカニズムの研究が挙げられる。
太陽は約11年周期で活動の大きさが変動することが知られており、活動が強い時、弱い時をそれぞれ極大期、極小期と呼ぶ。それに伴って太陽風の強さも変動し、極大期には太陽嵐も多く起こる。さらに、周期毎に活動の強さが異なることが過去の長期に渡る観測によって報告されている。太陽活動極小期において、極磁場（太陽の北極及び南極の磁場）の強さと次サイクルの太陽活動度には強い相関があることが知られており、現在の太陽活動極小期の極磁場を知る事は次期太陽サイクルを予測するのに有用である。
そこで本研究では差動回転、子午面循環流、乱流拡散係数などの表面磁束輸送モデル計算によって極磁場を見積もるのに重要なパラメターを太陽観測衛星SDO/HMIによる太陽磁場観測から求める。２つの異なる方法（Local Correlation Tracking (LCT)、Magnetic Element Tracking (MET)）で観測データから太陽のパラメ
ターを算出するモジュールを開発し、実際のデータ解析に用いた。LCTとMETから見積もられる結果を比較し、両者の方法での違い・特徴について議論を行う。また、打ち上げ(2010年)から現在までのデータ（およそ６年分）を解析することにより、太陽における３つの物理パラメターの長期変動について考察を行った結果を報告する。
キーワード：太陽、磁場観測、自転速度、子午面循環流
Keywords: Sun, Magnetic field observation, Rotation rate, Meridional flow

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P06 -PEM04-P07

日本地球惑星科学連合2016年大会

MHD磁束輸送ダイナモにおけるη抑制の役割
The role of η-quenching in MHD flux transport dynamo*市村 千晃1、横山 央明1*Chiaki Ichimura1, Takaaki Yokoyama1
1.東京大学大学院理学系研究科地球惑星科学専攻
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

日本地球惑星科学連合2016年大会

複数衛星粒子観測データを用いた静止軌道高エネルギー粒子環境の再構成
Reconstruction of high energy particle environment in geostationary orbit based on several
satellite observations*長妻 努1、坂口 歌織1、久保 勇樹1、越石 英樹2*Tsutomu Nagatsuma1, Kaori Sakaguchi1, Yuki Kubo1, Hideki Koshiishi2
1.国立研究開発法人

情報通信研究機構、2.国立研究開発法人

宇宙航空研究開発機構

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.
キーワード：宇宙天気予報、静止軌道、高エネルギー粒子観測
Keywords: Space Weather Forecast, Geostationary Orbit, High Energy Particle Observation©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P08 -PEM04-P09

日本地球惑星科学連合2016年大会

ISS/JEM-EF搭載SEDA-AP重イオン観測装置のデータ取得状況
The status of the SEDA-AP/Heavy Ion Telescope*上野 遥1、松本 晴久1、古賀 清一1*Haruka Ueno1, Haruhisa Matsumoto1, Kiyokazu Koga1
1.宇宙航空研究開発機構
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.
キーワード：国際宇宙ステーション、SEDA-AP、重イオン
Keywords: ISS, SEDA-AP, heavy ions©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P09 -PEM04-P10

日本地球惑星科学連合2016年大会

太陽サイクル24/25における銀河宇宙線の太陽変調と航空機搭乗員の被ばく線量
The solar modulation of galactic cosmic rays and radiation dose of aircrews during thesolar cycle 24/25
三宅 晶子1、*片岡 龍峰2、佐藤 達彦3
Shoko Miyake1, *Ryuho Kataoka2, Tatsuhiko Sato3
1.茨城工業高等専門学校、2.国立極地研究所、3.日本原子力研究開発機構
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.
キーワード：銀河宇宙線、太陽圏、被ばく線量、中性子モニター
Keywords: galactic cosmic rays, heliosphere, radiation dose, neutron monitor©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P10 -PEM04-P11

日本地球惑星科学連合2016年大会

二次宇宙線の種類に着目したエアロゾル核生成の検証実験
The verification experiment for aerosol nucleation focused on a kind of secondary cosmic
rays*鈴木 麻未1、増田 公明1、伊藤 好孝1、さこ 隆志1、松見 豊1、中山 智喜1、上田 紗也子、三浦 和彦2、草野完也1*Asami Suzuki1, Kimiaki Masuda1, Yoshitaka Itow1, Takashi Sako1, Yutaka Matsumi1, Tomoki Nakayama1,
Sayako Ueda, Kazuhiko Miura2, Kanya Kusano1
1.名古屋大学宇宙地球環境研究所、2.東京理科大学理学部
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

日本地球惑星科学連合2016年大会

地磁気急始変化（SC）振幅と太陽風動圧変化の関係
Relationship between solar wind dynamic pressure and amplitude of geomagnetic suddencommencement (SC)*荒木 徹1、新堀 淳樹2*Tohru Araki1, Atsuki Shinbori2
1.前

京都大学、2.京都大学生存圏研究所

1.Formerly Kyoto Univ., 2.RISH, Kyoto Univ.
太陽風衝撃波・不連続面の動圧（Pd）急増によって生じる地磁気急始変化（SC）は、地上観測からPd変化を知るプローブとして有効に使える。これは、飛翔体観測開始前時代には特に重要である。Siscoe etal.(1968)は、SC振幅(dH)が、Pd**0.5の衝撃波・不連続面前後の変化量、ｄ(Pd**0.5)に比例する（ ｄH=C・ｄ(Pd**0.5) ）と仮定して、観測から比例係数Cを定めた。その後、Cを決める幾つかの解析がなされている。、
SC振幅（ｄH）は、緯度とLTに依存して大きく変わる。これは、磁気圏急圧縮時には、磁気圏界面電流（MC）と共に、沿磁力線電流（FAC）・電離層電流（IC）・地電流（EC）も急変化し、それらの磁場が複雑な緯度・LT依存性を示すからである。しかし、Cを決める際に、この緯度・LT依存性は、考慮されてこなかった。
ここでは、FAC・ICが作る磁場日変化の計算と、赤道から中緯度までの４観測所のデータから求めたCの日変化の解析から、４－５ｈLTに観測されるSCは、FAC・ICの影響を最も受けにくく、MC変化（従って、Pd変化）を直接的に表しているとの結論を得た。
これに従って、1868年以降に観測された３大SC（柿岡でｄH＞200nT）の振幅のLT依存性を考察し、最大とされていた1940.3.24SCが、やはり最大であることを確かめた。
キーワード：地磁気急始変化(SC)、太陽風動圧、電離層電流、磁気圏電流、日変化、Siscoe関係式
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

日本地球惑星科学連合2016年大会

日本での電力トランスの地磁気誘導電流の測定計画について
On measurement plan of geomagnetic induced current of power transformers in Japan*亘 慎一1、海老原 祐輔2、藤田 茂3、後藤 忠徳4*Shinichi Watari1, Yusuke Ebihara2, Shigeru Fujita3, Tada-nori Goto4
1.情報通信研究機構、2.京都大学生存圏研究所、3.気象庁気象大学校、4.京都大学大学院工学研究科
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
日本は、地理緯度に比べて地磁気緯度が低いこともあり、地磁気誘導電流（GIC, Geomagnetically Induced
Current）による電力システムへの影響はそれほど大きくないと考えられている。しかし、2003年10月末から11月の始めにかけて発生した大きな地磁気嵐の際には、日本の北部とほぼ同じ磁気緯度に位置する南アフリカ共和国で、電力トランスの障害事例が報告されている。また、GICの大きさは、地下導電率構造に依存することが知られており、GICのモデリングにおいて日本の複雑な地下構造の影響を考慮する必要がある。GICのモデリ
ングのために計画しているGICの測定について報告する。
キーワード：地磁気誘導電流、地磁気嵐、電力システム
Keywords: geomagnetically induced current, geomagnetic storm, power system©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P13 -PEM04-P14

日本地球惑星科学連合2016年大会

磁気擾乱により励起されるGICの理解に向けた地上磁場変動の全成分解析
Three components analysis of ground magnetometer network data toward understanding GIC
excited by space weather disturbances*阿部 修司1、松下 拓輝2、縄田 由香利3、吉川 顕正4*Shuji Abe1, Hiroki Matsushita2, Yukari Nawata3, Akimasa Yoshikawa4
1.九州大学 国際宇宙天気科学・教育センター、2.九州大学 大学院理学府 地球惑星科学専攻、3.九州大学 理学部 地球惑星科学科、4.九州大学 大学院理学研究院 地球惑星科学部門
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.
キーワード：地磁気誘導電流、磁力計ネットワーク
Keywords: GIC, magnetometer network©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P14 -PEM04-P15

日本地球惑星科学連合2016年大会

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

日本地球惑星科学連合2016年大会

GAIAシミュレーションデータを用いたプラズマバブル発生確率の推定
Occurrence probability of plasma bubbles deduced from GAIA simulation data
*品川 裕之1、陣 英克1、三好 勉信2、藤原 均3、横山 竜宏1、大塚 雄一4*Hiroyuki Shinagawa1, Hidekatsu Jin1, Yasunobu Miyoshi2, Hitoshi Fujiwara3, Tatsuhiro Yokoyama1,
Yuichi Otsuka4
1.情報通信研究機構、2.九州大学、3.成蹊大学、4.名古屋大学
1.National Institute of Information and Communications Technology, 2.Kyushu University, 3.Seikei
University, 4.Nagoya University
プラズマバブルやスポラディックE層、SED (Storm Enhanced Density)などの電離圏擾乱現象は、通信、放送、測位などに障害を起こすため、宇宙天気予報における最重要課題の一つとなっている。これらの現象
は、一般に水平スケールが数100km以下のメソスケール現象であり、その予測には、リアルタイム電離圏観測と高精度の大気圏・電離圏モデルが必要である。我々のグループでは、電離圏擾乱現象の再現と予測を目的とした全大気圏-電離圏結合モデル（GAIA）を開発してきた。現在のGAIAは、これらのメソスケール現象を直接再現するには分解能がまだ十分でないが、プラズマバブルについては背景場から線形成長率を見積もることにより、発生しやすさを推定できる可能性がある。今回我々は、1996年から現在までの長期シミュレーション
データから、各日についてレイリーテイラー不安定の線形成長率の最大値を求め、プラズマバブル発生の観測
データと比較した。その結果、GAIAデータから計算された線形成長率が大きい期間は、実際にプラズマバブルが発生した期間に対応する傾向があることがわかった。この結果は、GAIAのシミュレーションデータを用いてプラズマバブルの発生確率を推定できる可能性を示すものと言える。
キーワード：プラズマバブル、GAIA、線形成長率、レイリー・テイラー不安定、電離圏じょう乱
Keywords: plasma bubble, GAIA, linear growth rate, Rayleigh-Taylor instability, ionosphericdisturbance©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P16 -PEM04-P17

日本地球惑星科学連合2016年大会

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

日本地球惑星科学連合2016年大会

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

日本地球惑星科学連合2016年大会

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

日本地球惑星科学連合2016年大会

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

日本地球惑星科学連合2016年大会

ニューラルネットワークを用いた太陽風入力によるfoF2の予報
Operational forecast of foF2 above Tokyo using solar wind input to a neural network*内田 ヘルベルト陽仁1,4、三宅 亙2、中村 真帆3、片岡 龍峰4,1*Herbert Akihito Uchida1,4, Wataru Miyake2, Maho Nakamura3, Ryuho Kataoka4,1
1.総合研究大学院大学、2.東海大学、3.東京学芸大学、4.国立極地研究所
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.
キーワード：予報、foF2、ニューラルネットワーク、太陽風Keywords: Forecast, foF2, Neural network, Solar wind©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P21 -PEM04-P22

日本地球惑星科学連合2016年大会

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

日本地球惑星科学連合2016年大会

高速太陽風における直線偏波・広帯域アルフベン波の非線形反射過程
Nonlinear reflection process of linearly-polarized, broadband Alfven waves in the fastsolar wind
*庄田 宗人1、横山 央明1*Munehito Shoda1, Takaaki Yokoyama1
1.東京大学大学院理学系研究科
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.).
キーワード：太陽風、アルフベン波Keywords: solar wind, Alfvén wave

©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P23 -PEM04-P24

日本地球惑星科学連合2016年大会

強く速度場が抑えられたときの太陽のエネルギー輸送について
Solar energy transport with significantly suppressed velocity*新井 祥太1、堀田 英之1*Shota Arai1, Hideyuki Hotta1
1.千葉大学理学部物理学科宇宙物理学研究室
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.
キーワード：太陽、熱対流、磁場
Keywords: Sun, Thermal convection, Magnetic field©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P24 -PEM04-P25

日本地球惑星科学連合2016年大会

太陽風モデルSUSANOOの改善に向けた研究
A study for the improvement of SUSANOO-solar wind model*石田 敏洋1、草野 完也1、塩田 大幸1*Toshihiro Ishida1, Kanya Kusano1, Daikou Shiota1
1.名古屋大学宇宙地球環境研究所
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.
キーワード：太陽風
Keywords: solar wind©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P25 -PEM04-P26

日本地球惑星科学連合2016年大会

3次元MHDシミュレーションにおける太陽コロナ中での背景場プラズマとCMEの相互作用
Three-Dimensional MHD Simulation of the Interaction between CME and Ambient Plasma in
Solar Corona*代田 真輝1、草野 完也1、塩田 大幸1*Masaki Shirota1, Kanya Kusano1, Daikou Shiota1
1.名古屋大学宇宙地球環境研究所
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.
キーワード：磁気流体力学、コロナ質量放出、コロナ
Keywords: magnetohydrodynamic, coronal mass ejections (CMEs), corona©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P26 -PEM04-P27

日本地球惑星科学連合2016年大会

太陽彩層伝播アルフベン波のモード変換と加熱への寄与
Mode Conversion of Alfven Waves Propagating in the Solar Chromosphere and Contribution to
the Heating*河野 隼也1、横山 央明1*Shunya Kono1, Takaaki Yokoyama1
1.東京大学
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.
キーワード：彩層、波、非線形、加熱
Keywords: chromosphere, wave, nonlinear, heating©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P27 -PEM04-P28

日本地球惑星科学連合2016年大会

対流圏及び成層圏の気温に対するオゾンと太陽風の影響
Influence of solar wind and ozone on the temperatures of the troposphere and stratosphere*山下 和良1、伊藤 公紀2*Kazuyoshi Yamashita1, Kiminori Itoh2
1.横浜国立大学大学院環境情報学府、2.横浜国立大学大学院環境情報研究院
1.Yokohama National University, 2.Inst.Env.Sci.&Technol.,Yokohama National Univ.
太陽磁気活動と地球大気の温度変化は相関関係にあることは間違いないが、その原因は明らかではない。この問題に対して今までの研究成果[1]に基づき、太陽風とオゾンが地球大気に与える影響について分析検討する。
今回、太陽風の影響を確認するためＡＥ指数データを使用し、オゾン全量と対流圏及び成層圏の気温の変化を解析した。
なお、解析を進めるにあたって次に点に注意した。低緯度でのオゾンに対するＥＰＰ－ＮＯｘの影響がＵＶ紫外線に匹敵する可能性がある[Callis et al.,2000,2001;Langematz et al.,2005;Rozanov et al.,2005]。低緯度で生成されたオゾンは冬極域に輸送されるため、ＥＰＰ－ＮＯｘが極域のオゾン減少に影響を与えている。
解析結果として、極域における５００ｈＰａ面の気温と８５０ｈＰａ面の気温から計算したショワルター安定指数（ＳＳＩ）は、ＡＥ指数と相関関係にあり、特に北極振動が正の位相から負の位相へ変化するときにその傾向が強い。このことは太陽風に伴う高エネルギー粒子の増加が、極域おける成層圏オゾンを減少させ、対流圏に到達する日射量を増加させることで、大気の安定度に影響を与えている可能性がある。
以上のことから太陽風の影響による成層圏オゾンの変化は、対流圏の気候に影響を与えていることを示唆している。
[1]伊藤公紀、地球惑星科学連合大会２００８－２０１５
キーワード：大気安定度、AE指数、北極振動、オゾン
Keywords: atmospheric stability, AE index, AO index, ozone©2016. Japan Geoscience Union. All Right Reserved.

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日本地球惑星科学連合2016年大会

13-14世紀の太陽活動移行期における宇宙気候と地球気候：元王朝の災異記録の検討を通して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.
*早川 尚志2、宮原 ひろ子5、玉澤 春史1、磯部 洋明3,4、片岡 龍峰6,7*Hisashi Hayakawa2, Hiroko Miyahara5, Harufumi Tamazawa1, Hiroaki Isobe3,4, Ryuho Kataoka6,7
1.京都大学大学院理学研究科附属天文台、2.京都大学大学院文学研究科、3.京都大学大学院総合生存学館、4.京都大学宇宙総合学研究ユニット、5.武蔵野美術大学、6.国立極地研究所、7.総合研究大学院大学
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.SOKENDAI
13世紀、太陽活動は急速に低調になり、中世極大期 (1100-1250) を終えて、所謂ウォルフ極小期 (1280-1340)に突入した。このような太陽活動の変化は地球にも大きな気候変動をもたらし、いわゆる中世温暖期(10c-13c) が終わり、小氷期 (14c-19c)が始まった。当初、ユーラシア大陸はモンゴル帝国による空前の世界帝国を経験し、東西の交易路が「モンゴルの平和」の下に統合される稀有な時代にあったが、かような世界帝
国も折からの気候変動には勝てず、小氷期の始まりと時期を同じくして解体し、その背景に異常気象による飢餓や社会不安があったことは夙に語られるところである。しかし、そのような異常気象については漠然とその存在が語られるのみで従来踏み込んだ検討がなされてこなかった。そこで本報告では、モンゴル治下中国 (元王朝: 1235-1368)の災異記録を検討し、C14などの科学データとの比較を通して、太陽活動の移行期に地球上にもたらされた異常気象の具体像に迫る。
キーワード：ウォルフ極小期、中世温暖期、太陽活動、異常気象
Keywords: Wolf Minimum, Medieval Warm Period, solar activity, Extreme Terrestrial Weathers©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P29 -PEM04-P30

日本地球惑星科学連合2016年大会

Aurora Candidates from the Chronicles of Qīng Dynasties for Decoding Past Solar Activities
Aurora Candidates from the Chronicles of Qing Dynasties for Decoding Past Solar Activities*河村 聡人1、早川 尚志2、玉澤 春史1、磯部 洋明3,4*Akito Davis Kawamura1, Hisashi Hayakawa2, Haruhumi Tamazawa1, Hiroaki Isobe3,4
1.京都大学大学院理学研究科附属天文台、2.京都大学大学院文学研究科、3.京都大学大学院総合生存学館、4.京都大学宇宙総合学研究ユニット
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 Qīng dynasties,

Qīngshǐgǎo (清史稿), the draft chronicle of Qīng dynasty (1644-1912 CE). In total we found 111
records of aurora candidates associated with the keywords such as vapor (氣, qì), cloud (雲, yún), and light (光, guāng). Among the 111 records we found, 14 records are considered as very likely
to be low latitude auroras with corresponding records of simultaneous observation in the westernworld, and 6 records are newly found low latitude aurora candidates after moon phase analysis inorder to eliminate a possibility of atmospheric optics involving. Some of our presenting candidatesof low latitude aurora are dated during the Maunder minimum, and therefore we would suggest ourpresenting data potentially helpful for further discussion on past solar activities.
キーワード：オーロラ、宇宙天気、歴史資料
Keywords: Aurora, Space Weather, Historical Resources©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P30 -PEM04-P31

日本地球惑星科学連合2016年大会

個別の衛星のためのテーラーメード型宇宙環境予測モデルの開発
Development of user-oriented space environment prediction model for individual satellite*長妻 努1、松本 晴久2、古賀 清一2、中村 雅夫3、石井 守1*Tsutomu Nagatsuma1, haruhisa matsumoto2, Kiyokazu Koga2, Masao Nakamura3, Mamoru Ishii1
1.国立研究開発法人

情報通信研究機構、2.国立研究開発法人

宇宙航空研究開発機構、3.公立大学法人

大

阪府立大学
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.
キーワード：宇宙天気予報、衛星帯電、テーラーメード型
Keywords: Space Weather Forecast, Spacecraft Charging, User-Oriented©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P31 -PEM04-P32

日本地球惑星科学連合2016年大会

航空用通信・航法・監視システムに対する宇宙天気現象の影響について
Space weather effects on aeronautical communication, navigation and surveillance systems*斎藤 享1、石井 守2*Susumu Saito1, Mamoru Ishii2
1.電子航法研究所航法システム領域、2.情報通信研究機構
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.
キーワード：航空利用、電離圏、通信・航法・監視システム
Keywords: aeronautical applications, ionosphere, communications, navigation, and surveillancesystems©2016. Japan Geoscience Union. All Right Reserved.

- PEM04-P32 -