資料8-H

Japanese URSI Commission H (Waves in Plasmas)
Activity Report
July 2014 - November 2014[1] Status of projects related with plasma wave observation
1.

The ERG project
http://ergsc.stelab.nagoya-u.ac.jp/index.shtml.en

2.

BepiColombo/MMO
http://www.stp.isas.jaxa.jp/mercury/p_mmo.html

3.

STEL VLF/ELF observations are carried out in Canada and Japan.
Details of the data are available at
http://stdb2.stelab.nagoya-u.ac.jp/vlf/index.html

4.

Conjugate campaign observation between Syowa and Iceland, September, 2014.

5.

NICT Science Cloud
NICT Science Cloud has been developed for space plasma studies. We have begun todevelop a Web application for plasma wave data and other satellite observation
data, which is named “STARStouch”. This Web application is based on a techniqueof asynchronous data transfer of graphic files for several types of data plots.
We implemented new functions on the STARStouch: data plot informationexchange system. Figure 1 shows the function of information exchange. User who
takes a look of data saves “data plot information” described in a URL format.
Another user reproduces exact same plot on his/her terminal by the URL.

Figure 1: STARStouch GEOTAIL version: http://geotail.nict.go.jp

資料8-H[2] Recent Meetings
1.

6th Alfven Conference, “Plasma Interactions with Solar System Objects”, London,
UK, 7-11 July, 2014.

2.

Asia Oceania Geosciences Society (AOGS) 11th Annual Meeting, Sapporo, Japan,
28 July - 1 August, 2014.

3.

The 40th COSPAR Scientific Assembly, Moscow, Russia, 2-10 August, 2014.

4.

The 31st URSI GASS, Beijing, China, 16-23 August, 2014.

5.

AGU Chapman Conference on “Low Frequency Waves in Space Plasmas”, Jeju,
Korea, 31 August - 5 September, 2014.

6.

European Planetary Science Congress 2014, Estoril, Portugal, 7-12 September,
2014.

7.

URSI-JRSM 2014, Tokyo, Japan, 8 September, 2014.

8.

Geospace revisited: a Cluster / MAARBLE / Van Allen Probes Conference, Rhodes,
Greece, 15-20 September, 2014.

9.

Taiwan-Japan Workshop 2014: Laboratory astrophysics with ultra intense lasers,
Taoyuan, Taiwan, 14-15 October, 2014.

10. SGEPSS fall meeting 2014, Matsumoto, Japan, 31 October - 3 November, 2014.
11. The 12th International Conference on Substorms (ICS-12), Ise, Japan, 10-14
November, 2014.
12. Plasma conference 2014, Niigata, Japan, 18-21 November, 2014.
13. High energy astrophysics 2014, Fukuoka, Japan, 23-25 November, 2014.

[3] Future Meetings
1.

Meeting on waves in plasmas 2014, Kyoto, Japan, 5 December, 2014.

2.

The Fifth Symposium on Polar Science, Tokyo, Japan, 2-5 December, 2014.

3.

Inner magnetosphere coupling III, UCLA, March 23-27, 2015.

4.

ISAR-4, Toyama, Japan, 27-30 April, 2015.

5.

Japan Geoscience Union Meeting 2015, Chiba, Japan, 24-28 April, 2015.

6.

The 26th General Assembly of the International Union of Geodesy and Geophysics(IUGG) , Prague, Czech Republic, 22 June - 2 July, 2015.

7.

The 12th International School/Symposium for Space Simulations (ISSS-12), Prague,
Czech Republic, July 3-10, 2015.

8.

Asia Oceania Geosciences Society (AOGS) 12th Annual Meeting, Singapore, 2-7
August, 2015.

資料8-H[4] Recently Published Papers (July 2014 – November 2014)
1.

K. Shiokawa, Y. Yokoyama, A. Ieda, Y. Miyoshi, R. Nomura, S. Lee, N. Sunagawa, Y.
Miyashita, M. Ozaki, K. Ishizaka, S. Yagitani, R. Kataoka, F. Tsuchiya, I. Schofield,
and M. Connors, Ground-based ELF/VLF chorus observations at subauroral
latitudes-

VLF-CHAIN

Campaign,

J.

Geophys.

Res.,

119,

doi:10.1029/2014JA020161, 2014. (published online Aug.27, 2014).
This is a report of observations of ELF/VLF chorus waves taken during the
VLF/ELF Campaign observation with High-resolution Aurora Imaging Network(VLF-CHAIN) of 17-25 February, 2012, at subauroral latitudes at Athabasca(L=4.3), Canada. ELF/VLF waves were measured continuously with a sampling
rate of 100 kHz to monitor daily variations in VLF/ELF emissions and derive theirdetailed structures.

We found quasi-periodic (QP) emissions whose repetition

period changes rapidly within a period of 1 h without corresponding magnetic
pulsations.
QP emissions showed positive correlation between amplitude and frequency sweep
rate, similarly to rising-tone elements. We found an event of nearly simultaneousenhancements of QP emissions and Pc1/EMIC wave intensities, suggesting that thetemperature anisotropy of electrons and ions developed simultaneously at theequatorial plane of the magnetosphere.

We also found QP emissions whose

intensity suddenly increased in association with storm sudden commencement
without changing their frequency. Falling-tone ELF/VLF emissions were observedwith their rate of frequency change varying from 0.7 to 0.05 kHz/s over 10 min.
Bursty-patch emissions in the lower and upper frequency bands are often observed
during magnetically disturbed periods.

Clear systematic correlation between

these various ELF/VLF emissions and cosmic noise absorption was not obtained
throughout the campaign period. These observations indicate several previously
unknown features of ELF/VLF emissions in subauroral latitudes and demonstrate
the importance of continuous measurements for monitoring temporal variations inthese emissions.
2.

Minoru Tsutsui, Behaviors of Electromagnetic Waves Directly Excited by
Earthquakes, IEEE Geoscience and Remote Sensing LETTERS, Vol. 11, No. 11,
pp.1961-1965, doi:10.1109/LGRS.2014.2315208, November, 2014.
We detected electromagnetic (EM) waves directly excited by earthquakes in a deep
borehole and confirmed them by simultaneous capturing of their waveforms and ofseismic waves measured at the same observation site. Furthermore, the excitation

資料8-Hmechanism of the EM pulse was confirmed as the piezoelectric effect by alaboratory experiment, in which a seismic P-wave was readily generated by a small
stress impact, and the EM wave was simultaneously excited basically by the
P-wave. Here, we show behaviors of seismic waves and of their excited EM waves
when small and large earthquakes occurred. We also found that the EM waves
excited by seismic waves have leaked out of the ground surface.
3.

Y. Omura, Theory and simulations of nonlinear wave-particle interactions inplanetary radiation belts, Radio Science Bulletin, 349, 52-58, 2014.
We give a brief account of the nonlinear theory of the generation mechanism ofchorus emissions, which has been revealed by the simulations and observations. We
describe the nonlinear dynamics of resonant electrons, and the formation of theelectromagnetic electron “hole” that results in resonant currents generating
rising-tone emissions. In contrast, falling-tone emissions are generated through theformation of electron “hills.” We also describe the mechanism of nonlinear wave
damping due to quasi-oblique propagation, which results in the formation of a gap
at half the electron cyclotron frequency.

4.

K. H. Lee, Y. Omura, and L. C. Lee, Electron acceleration and diffusion of ring
distribution by Z-mode and whistler-mode waves, Radio Science Bulletin, 349, 7-17,
2014.
We present a brief review of wave generation via the cyclotron maser instability byan electron ring distribution, and the associated electron acceleration by the excited
Z-mode and whistler-mode waves. The electron ring distribution can excite X-mode
waves mainly in the perpendicular direction, Z-mode waves in the perpendicularand parallel directions, and whistler-mode waves in the parallel direction.

5.

C. J. Rodger, M. A. Clilverd, W. Li, M. P. McCarthy, Y. Omura, and C. E. Weaver,Drivers, detection, and impacts of precipitation from the radiation belts, Radio
Science Bulletin, 349, 60–67, 2014.
Particle precipitation into the atmosphere is believed to be one of the dominantmechanisms for the loss of energetic electrons from the Van Allen radiation belts.
Wave-particle interactions involving ULF through to VLF waves are thought to beimportant drivers of these loss events. There is growing interest in energetic
electron precipitation (EEP). Much of the renewed interest comes from NASA’s
recent Van Allen Probes mission, which has stimulated new experimental and資料8-H

theoretical research and opened up new understanding into the fundamental
physical processes of radiation-belt dynamics.
6.

B. Kakad, A. Kakad, and Y. Omura, Nonlinear evolution of ion acoustic solitary
waves in space plasmas: Fluid and particle-in-cell simulations, J. Geophys. Res.
Space Physics, 119, 5589-5599, doi:10.1002/2014JA019798, 2014.
We perform both fluid and particle-in-cell (PIC) simulations of ion acoustic solitary
waves (IASWs) and estimate the quantitative differences in their characteristics
like speed, amplitude, and width. We find that the number of trapped electrons in
the wave potential is higher for the IASW, which are generated by large-amplitude
initial density perturbation (IDP). The present fluid and PIC simulation results are
in close agreement for small amplitude IDPs, whereas for large IDPs they show
discrepancy in the amplitude, width, and speed of the IASW, which is attributed tonegligence of kinetic effects in the former approach.

7.

D. Summers, Y. Omura, S. Nakamura, C. A. Kletzing, Fine structure ofplasmaspheric hiss, J. Geophys. Res., Space Physics, doi: 10.1002/2014JA020437,
2014.
In this study, by examining burst-mode vector waveform data from the Electric andMagnetic Field Instrument Suite and Integrated Science instrument on the Van
Allen Probes mission, we show that plasmaspheric hiss is a coherent emission withcomplex fine structure. Specifically, plasmaspheric hiss appears as discrete rising
tone and falling tone elements.

8.

H. S. Fu, J. B. Cao, Z. Zhima, Y. V. Khotyaintsev, V. Angelopoulos, O. Santolík, Y.
Omura, U. Taubenschuss, L. Chen, S. Y. Huang, First observation of rising-tone
magnetosonic waves, Geophy. Res. Lett., DOI: 10.1002/2014GL061867,
Magnetosonic (MS) waves are linear-polarized emissions confined near themagnetic equator with wave normal angle near 90° and frequency below the lower
hybrid frequency. Such waves, also termed equatorial noise (EN), were traditionallyknown to be “temporally continuous” in their time-frequency spectrogram. Here weshow for the first time that MS waves actually have discrete wave elements withrising-tone features in their spectrogram. The frequency sweep rate of MS waves,~1 Hz/s, is between that of chorus and EMIC waves.

9.

Nosé, M., K. Takahashi, K. Keika, L. M. Kistler, K. Koga, H. Koshiishi, H.

資料8-H

Matsumoto, M. Shoji, Y. Miyashita, and R. Nomura, Magnetic fluctuations
embedded in dipolarization inside geosynchronous orbit and their associatedselective acceleration of O+ ions, J. Geophys. Res., 119, doi:10.1002/2014JA019806,
2014.
We study magnetic fluctuations embedded in dipolarizations in the innermagnetosphere (a geocentric distance of ≤6.6 RE) and their associated ion fluxchanges, using the Engineering Test Satellite VIII and Active MagnetosphericParticle Tracer Explorers/CCE satellites. We select seven events of dipolarizationthat occur during the main phase of magnetic storms having a minimum value of
the Dst index less than −40 nT. It is found that (1) all of the dipolarization events
are accompanied by strong magnetic fluctuations with the major frequency close to
the local O+ gyrofrequency; (2) the magnetic fluctuations appear with significant
amplitude in the component nearly parallel to the local magnetic field; (3) thestrong flux enhancement is seen in the energy range of 1–10 keV only for O+ ions.
In terms of frequency and dominant components of the magnetic fluctuations, they
are considered to be excited by the drift-driven electromagnetic ion cyclotron(EMIC) instability that is recently identified with the linear theory. We performparticle tracing for H+ and O+ ions in the electromagnetic fields modeled by thelinear dispersion relation of the drift-driven EMIC instability. Results show that
the O+ ions are accelerated to the energy range of 0.5–5 keV and undergo asignificant modification of the spectral shape, while the H+ ions have no clear
change of spectral shape, being consistent with the observations. We therefore
suggest that the electromagnetic fluctuations associated with the dipolarizations
can accelerate O+ ions locally and nonadiabatically in the inner magnetosphere.
This selective acceleration of O+ ions may play a role in enhancing the O+ energy
density in the storm time ring current.
10. Katoh, Y., A simulation study of the propagation of whistler-mode chorus in the
Earth’sinnermagnetosphere,

Earth,

Planets

Space,

whistler-mode

chorus66:6,

doi:10.1186/1880-5981-66-6, 2014.
Katoh[2014]

studiedthepropagation

of

in

the

magnetosphere by a spatially two-dimensional simulation code in the dipole
coordinates. He set the simulation system so as to assume the outside of theplasmapause, corresponding to the radial distance from 3.9 to 4.1 RE in theequatorial plane and the latitudinal range from −15° to +15°, where R E is the
Earth’s radius. He assumed a model chorus element propagating northward from

資料8-Hthe magnetic equator of the field line at L=4 with a rising tone from 0.2 to 0.7 Ωe0in the time scale of 5,000 , where Ωe0 is the electron gyrofrequency at the magnetic
equator. For the initial density distribution of cold electrons, he assumed three
types of initial conditions in the outside of the plasmapause: without a duct (run 1),
a density enhancement duct (run 2), and a density decrease duct (run 3). In run 1,
the simulation result reveals that whistler-mode waves of the different wave
frequencies propagate in the different ray path in the region away from themagnetic equator. In runs 2 and 3, the model chorus element propagates inside theassumed duct with changing wave normal angle. The simulation results show thedifferent propagation properties of the chorus element in runs 2 and 3 and revealthat resultant wave spectra observed along the field line are different between thedensity enhancement and density decrease duct cases. The spectral modification ofchorus by the propagation effect should play a significant role in the interactions
between chorus and energetic electrons in the magnetosphere, particularly in theregion away from the equator. The present study clarifies that the variation of
propagation properties of chorus should be taken into account for the thoroughunderstanding of resonant interactions of chorus with energetic electrons in the
inner magnetosphere.
11. Kalaee, M. J., and Y. Katoh, A simulation study on the mode conversion processfrom slow Z-mode to LO mode by the tunneling effect and variations of beaming
angle, Adv. Space Res., 54(11), 2218-2223, doi:10.1016/j.asr.2014.08.025, 2014.
Kalaee and Katoh [2014] investigated the effect of the spatial scale of the density
gradient on the mode conversion efficiency in an inhomogeneous plasma where themode conversion can occur only by the tunneling effect. For a particular angle ofincidence wave, it is possible for a slow Z-mode wave incident on an inhomogeneous
plasma slab to be converted into an LO mode wave. But for another wave normal
angle of the incident wave, it has been considered impossible, since an evanescenceregion exists between two mode branches. In this case they expected that the mode
conversion takes place through the tunneling effect. They used the computer
simulation solving Maxwell’s equations and the motion of a cold electron fluid. By
considering the steepness of the density gradient, the simulation results show theefficient mode conversion could be expected even in the case that the mismatch of
the refractive indexes prevents the close coupling of plasma waves. Also, they
showed for these cases the beaming angle does not correspond to Jones’ formula.
This effect leads to the angles larger and smaller than the angle estimated by the資料8-H

formula. This type of mode conversion process becomes important in a case where
the different plasmas form a discontinuity at their contact boundary.
12. Tsugawa, Y., Y. Katoh, N. Terada, T. Ono, H. Tsunakawa, F. Takahashi, H. Shibuya,
H. Shimizu, and M. Matsushima, Group-standing of whistler-mode waves near theMoon, J. Geophys. Res. Space Physics, 119, 2634-2648, doi:10.1002/2013JA019585,
2014.
Narrowband whistler mode waves with frequencies near 1 Hz have been observed
near the Moon. Tsugawa et al [2014] revealed that the narrowband spectra, thefrequency concentration near 1 Hz, and the relations between the wave vector,
magnetic field vector, and sunward directions can be explained by a condition inwhich the group velocity vector is almost canceled by the solar wind velocity vector
in the spacecraft frame. Hereafter, they referred to this condition as thegroup-standing condition. The spectral density is modified and has a peak at thefrequency satisfying the group-standing condition because of the difference of thefrequency width between the solar wind plasma frame and the spacecraft frame. In
addition, if the waves were decelerated to be group-standing, the conservation of
the energy flux results in the intensification of the wave amplitude at thatfrequency. They also derived the analytical expression of the amount of themodifications, which depend on the group velocity. These effects can explain the
narrowband spectra near 1 Hz and support the relations between the wave vector,
magnetic field vector, and sunward directions. The estimated frequency which
satisfies the group-standing condition is in good agreement with the observed
frequency within error bars of the estimation. Considering the group-standing
condition, they suggested that the narrowband waves observed in the spacecraft
frame are originated from oblique whistler mode waves in the frequencies near the
lower hybrid frequency, which are possibly generated by reflected ions from thelunar magnetic anomalies.
13. Morioka, A., Y. Miyoshi, Y. Kasaba, N. Sato, A. Kadokura, H. Misawa, Y. Miyashita,
and I. Mann, Substorm onset process: Ignition of auroral acceleration and related
substorm

phases,J.

Geophys.

Res.

Space

Physics,

119(2),

1044-1059,

doi:10.1002/2013JA019442, 2014.
Morioka et al. [2014] studied the substorm onset process on the basis of the verticalevolution of auroral acceleration regions derived from auroral kilometric radiation(AKR) spectra and Pi pulsations on the ground. The field-aligned auroral資料8-H

acceleration at substorm onset demonstrated two distinct phases. Low-altitude
acceleration (h~3000–5000 km), which accompanied auroral initial brightening,prebreakup Pi2, and direct current of ultralow frequency (DC-ULF) pulsation werefirst activated and played an important role (precondition) in the subsequent
substorm expansion phase onset. Prebreakup Pi2 is suggestive of the ballooning
mode wave generation, and negative decrease in DC-ULF suggests increasing
field-aligned current (FAC). They called this stage the substorm initial phase. A few
minutes after this initial phase onset, high-altitude acceleration, whichaccompanied auroral breakup and poleward expansion with breakup Pi1 and Pi2
pulsations, suddenly broke out in an altitude range from 8000 to 16,000 km. Thus,
substorm expansion onset originated in the magnetosphere-ionosphere (M-I)
coupling region, i.e., substorm ignition in the M-I coupling region. Statisticalinvestigations revealed that about 65% of earthward flow bursts observed in theplasma sheet were accompanied by enhanced low-altitude AKR, suggesting thatflow braking of bursts causes FAC and resulting low-altitude field-aligned
acceleration in the M-I coupling region. On the basis of these observations, they
propose a substorm onset scenario in which FAC that originated from the braking ofplasma flow bursts first enhances low-altitude acceleration (substorm initial phase
onset) and then the increasing FAC induces current-driven instability in the M-I
coupling region, which leads to high-altitude acceleration and resulting substorm
expansion phase onset.
14. Kurita, S., Y. Miyoshi, C. M. Cully, V. Angelopoulos, O. Le Contel, M. Hikishima,and H. Misawa, Observational evidence of electron pitch angle scattering driven by
ECH waves, Geophys. Res. Lett., doi:2014GL061927R, in print, 2014.
Using the plasma wave and electron data obtained from THEMIS, Kurita et al.
showed a signature of electron pitch angle scattering driven by Electrostatic
Cyclotron Harmonic (ECH) waves in the velocity distribution function (VDF). The
diffusion curve of whistler-mode waves is used as a proxy to identify changes in
VDFs due to wave-particle interactions. They confirmed that the shape of the VDF
well agrees with the diffusion curve of whistler-mode waves when whistler modechorus alone is active. On the other hand, they found that the shape of the VDF
deviates from the diffusion curves at low pitch angles when ECH waves are active
following the inactivation of chorus waves. The result is observational support forelectron pitch angle scattering caused by ECH waves and suggests that ECH waves
can contribute to generation of diffuse auroras.

資料8-H

15. Y. Oike, Y. Kasahara, and Y. Goto, Spatial Distribution and Temporal Variations ofOccurrence Frequency of Lightning whistlers Observed by VLF/WBA onboard
Akebono, Radio Science, doi:10.1002/2014RS005523, 49, 2014.
They statistically analyzed lightning whistlers detected from the analog waveform
data below 15 kHz observed by the VLF instruments onboard Akebono. Largeamount of data obtained at Uchinoura Space Center in Japan for 22 years from1989 to 2010 were used for the study. It was found that the lightning whistlers weremainly observed inside the L shell region below 2. Seasonal dependence of theoccurrence frequency of lightning whistlers has two peaks around July to Augustand December to January. As lightning is most active in summer, in general, thesetwo peaks correspond to summer in the Northern and Southern Hemispheres,
respectively. Diurnal variation of the occurrence frequency showed that lightning
whistlers begin to increase in the early evening and remain at a high-occurrence
level through the night with a peak around 21 in magnetic local time (MLT). This
peak shifts toward nightside compared with lightning activity, which begins to risearound noon and peaks in the late afternoon. This trend is supposed to be caused byattenuation of VLF wave in the ionosphere in the daytime. Comparison study withthe ground-based observation revealed consistent results, except that the peak of
the ground-based observation appeared after midnight while our measurements
obtained by Akebono was around 21 in MLT. This difference is explained
qualitatively in terms that lightning whistlers measured at the ground station
passed through the ionosphere twice above both source region and the groundstation. These facts provide an important clue to evaluate quantitatively theabsorption effect of lightning whistler in the ionosphere.
16. Ken T. Murata, Kentaro Ukawa, Kazuya Muranaga, Yutaka Suzuki, Hidenobu
Watanabe, Koji Zettsu, Kazunori Yamamoto, Iku Shinohara, Yoshiya Kasahara,
Masaki Okada, Hirotsugu Kojima, Masahito Nose, Eizen Kimura, Osamu Tatebeand Masahiro Tanaka, A Web Application of Interdisciplinary Data Analysis
Designed for ICSU World Data System, Journal of Japan Society of Information
and Knowledge, Vol.24, No.3, pp.297-320, 2014.
In 2008 International Council for Science (ICSU) has established World Data
System (WDS). The WDS ensures the long-term stewardship and provision ofquality-assessed data and data services to the international science community andother stakeholders. One of the objectives of the WDS is to support and make

資料8-H

progress of interdisciplinary studies in research fields. The NICT Science Cloud
started to realize the concept of the WDS. In this study we propose a Web
application for interdisciplinary researches working on the NICT Science Cloud.
Based on our design of the Web with help of HTML5 and Ajax technologies, we
implemented a Web using a couple of mission datasets. Data plots are previewed on
the Web application with higher usability than traditional data plot tools.
17. Ken T. Murata, Hidenobu Watanabe, Kentaro Ukawa, Kazuya Muranaga, Yutaka
Suzuki, Kazunori Yamamoto and Eizen Kimura, A Report of the NICT Science
Cloud in 2013, Journal of Japan Society of Information and Knowledge, Vol.24,
No.3, pp.275-290, 2014.
In many scientific fields, most data are digitized and handled on computers andnetworks. The data files are getting larger in size and numbers. Science clouds,
which are equipped with both flexibility and specialty applicable for countlessscientific studies, are believed to play important roles as an infrastructure of
big-data sciences and inter-disciplinary studies. The NICT Science Cloud isdesigned to work with functions of data crawling and transfer, data preservationand management, and data processing and visualization. We have developed
applications, tools, systems and services designed for these three functions(especially for Earth and space environmental sciences) installed on the NICT
Science Cloud. By applying these functions to each science project, researchers areable to advance their studies. In this paper, we first introduce the NICT Science
Cloud. We next report our 2-years operations of the cloud system based on several
fact data. Finally, results of research works using the cloud system are discussedwith focusing on how we effectively take advantage of a cloud system on researchworks in various fields.
18. Hidenobu WATANABE, Sen UENO, Ken. T. MURATA, A Method for Cooperation
with A Secure Web Application Development by The NICT Science Cloud, Journalof Japan Society of Information and Knowledge, Vol.24, No.3, pp.291-296, 2014.
A web application is important technology as a user interface of open scientific data,
but it is required to develop without vulnerability. NICT is also required to aframework which enables to develop a secure web application even if a client does
not have enough development skills or specialized knowledge. This paper reports
about the proposed method for cooperation with a secure web application
development to a client in general competitive bidding.

資料8-H

19. Watanabe, H., Ushiyama, S., Muto, Y., Iwama, T. and Murata, K. T., Improvementof The Integrity Verification Application using Timestamp Mechanism forDistributed File System, The 38th Annual International Computers, Software &Applications Conference 2014 (COMPSAC2014), Vasteras, Sweden, Jul. 21-25,
2014..
The 3D phased array radar equipped in the Osaka University of Japan rotates in 30
seconds to capture a 3D structure of (strong) rain within 60km in radius and 15km
in altitude. We have succeeded in developing a real-time 3D visualization system
which enables to draw the 3D animation of rain structure (51MB/step) at a remoteclient computer of Tokyo within 70 seconds after every rotation. A key technology ofthis system is a parallel data processing by a Gfarm file system with 180 CPU coresand 32Gbps read I/O. Gfarm is a distributed file system made in Japan. Network
between Osaka and Tokyo is 10Gbps Ethernet provided by JGN-X which is a
research and education network of Japan. That is network performance is almost
certain to be lower than disk performance. This system therefore also has a SDN
control function by OpenFlow to avoid an overload network link between servers
and a client computer as a possible. In SC14, we prepare two the same systems andconfigure SDN on global research and education networks between Japan and U.S.A(Pacific Wave and Internet2) by RISE which is a wide-area OpenFlow testbed ofJapan. Our demo will show 3D drawing performance using observation data 70
seconds ago on a client computer screen at the NICT Booth (No.513) of New Orleans.
In addition, we are going to compare two animations and show eectiveness
depending on whether the SDN control is available or not when the network became
overload.