PEM09-P01

Japan Geoscience Union Meeting 2016

Development of MU radar real-time processing system with adaptive clutter rejection*Hiroyuki Hashiguchi1, Takahiro Manjou1, Mamoru Yamamoto1, Toru Sato2, Koji Nishimura3, Taishi
Hashimoto2
1.Research Institute for Sustainable Humanosphere, Kyoto University, 2.Graduate School ofInformatics, Kyoto University, 3.National Institute of Polar Research (NIPR)
Strong clutter echoes from a hard target such as a mountain or building sometimes cause problems ofobservations with atmospheric radars. In order to reject or suppress clutter echoes, it iseffective to use NC-DCMP (Norm Constrained-Directionally Constrained Minimum Power) method, whichmakes null toward the direction of the clutter, if we can receive signals independently from pluralantennas [Nishimura et al., JTech., 2012]. It has been demonstrated that the NC-DCMP method iseffective to real observation data with the MU (Middle and Upper atmosphere) radar, but it wasprocessed in off-line. The objective of this study is to implement the clutter rejection by NC-DCMP
method into the on-line processing system of the MU radar. NC-DCMP method suppresses clutter echoeswith maintaining the shape of main lobe to add pseudo-noise.
The MU radar is operated in a troposphere-stratosphere standard observation mode for about 100
hours every month. First we implemented the NC-DCMP processing to this standard observation mode.
Observation data in this mode is obtained once every 8 seconds. Therefore it is necessary to
perform all of the signal processing within 8 seconds in order to perform the clutter suppression
in real-time. Now we can process the NC-DCMP in 1 second in average. Since the echoes frommountains and buildings do not change so quickly, it showed good results to determine the optimum
weight vector using the received signal of the incoherent integration 7 times (about one minute).
We have applied the NC-DCMP realtime processing since November 2015. Although it is it not perfectfor the echoes from the aircraft, the effect of suppressing is obtained.
We can apply the achievement of this study to the Equatorial MU radar (EMU), which is proposed tobe constructed at West Sumatera, Indonesia. The EMU system is the similar as the MU radar, but its
antenna consists of 1045 Yagi antennas with 55 groups.
Keywords: Atmospheric radar, Clutter rejection, NC-DCMP method, MU radar©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P01 -PEM09-P02

Japan Geoscience Union Meeting 2016

Variability of Rain Microstructure over Sumatra from Micro Rain Radar Observation*Marzuki Marzuki1, Indah Rahayu1, Hiroyuki Hashiguchi2, Toyoshi Shimomai3
1.Department of Physics, Andalas University, 2.Research Institute for Sustainable Humanosphere(RISH), Kyoto University, 3.Shimane University
The vertical profile of rain microstructure such as raindrop size distribution (DSD) is importantfor understanding rain formation processes and to improve the accuracy of radar-derived rainfall
estimates. The variability in the DSD substantially limits the accuracy of the DSD application. The
aim of the present study is to investigate the natural variability of vertical profile of DSDs as afunction of large-scale atmospheric conditions and storm characteristics using measurements fromthe Equatorial Atmospheric Radar (EAR) facility at Kototabang, west Sumatra, Indonesia. This study
is a follow-up of our previous work on the DSD variability over Sumatra [1,2]. The vertical profile
of DSD is obtained from a Micro Rain Radar (MRR) with a near continuous record of operation overfour consecutive years (2011–2014). The DSDs from the radar are compared with those from an optical
disdrometer. The data are partitioned according to diurnal, convective and stratiform precipitation
classifications, monsoonal regime, and MJO phase. Findings support previous Sumatra studies
suggesting a significant diurnal and DSD parameter signal associated with bothconvective–stratiform and MJO phase regime classification. Negligible monsoonal phase influence isdetermined for the DSD over the Kototabang location. The natural variability of vertical profile of
DSDs leads to variability of Z-R relationships in rain column.
[1] Marzuki, Hashiguchi, H., Yamamoto, M. K., Mori, S., and Yamanaka, M. D.: Regional variabilityof raindrop size distribution over Indonesia, Ann. Geophys., 31, 1941-1948,
doi:10.5194/angeo-31-1941-2013, 2013.
[2] Marzuki, Hiroyuki Hashiguchi, Toshiaki Kozu, Toyoshi Shimomai, Yoshiaki Shibagaki, Yukihiro
Takahashi, Precipitation microstructure in different Madden–Julian Oscillation phases over Sumatra,
Atmospheric Research, Volume 168, 1 February 2016, Pages 121-138.
Keywords: Raindrop size distribution, Micro Rain Radar, Sumatra©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P02 -PEM09-P03

Japan Geoscience Union Meeting 2016

DIURNAL VARIABILITIES ANALYSIS OF METEOROLOGICAL PARAMETER OF CCAM-NWP OUTPUTS AND
OBSERVATION AT KOTOTABANG*Sofiati Iis Soeratman1, Lely Qodrita Avia1, Nurzaman Adikusumah1
1.Indonesian National Institute of Aeronautics and SpaceThe diurnal varibilities of some meteorological parameter (rainfall, temperature, relative
humidity, and pressure) study, needed a model that can predict the behavior of the weather in the
future by following the data history in the past. As a validation stage, outcomes such dynamic
model of spatial and temporal very necessary compared with surface observational data from
Automatic Weather Station (AWS) and u-v wind data from Equatorial Atmosphere Radar (EAR). The
purpose of this study is analyzing the diurnal varibilities of meteorological parameter of dynamic
model outputs Conformal Cubic Atmospheric Model-Numerical Weather Prediction (CCAM-NWP), and thesurface observational data. The data used is the hourly output CCAM-NWP models in (12-15) February,(12-15) June 2014, and (2-14) January 2015, and surface observational data in (2-4) January 2015 asvalidation. The method on analyzing the output CCAM-NWP from the input models Global Forecast
System (GFS-NOAA) with a resolution of the model 0.25o x 0.25o, and statistical analysis withmethod of T-test and F-test. Based on the results shown the diurnal variabilities and dinamic
process of meteorological parameter for the model output and surface observation. Furthermore, we
obtained a weak correlation between the temporal model output with surface observations fromstatistical analysis which mean that there are significant differences of the results found fromthe CCAM-NWP output and surface observations. Additionally, we compared spatial distribution ofhourly output CCAM-NWP with satellite observation data such as MTSAT.
Keywords: rainfall, temperature, relative humidity, pressure, CCAM-NWP, T-test, MTSAT.

©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P03 -PEM09-P04

Japan Geoscience Union Meeting 2016

Solar-Terrestrial Interaction as Studied from Total Solar Eclipse of 9 March 2016
*Rhorom Priyatikanto1, Tiar Dani1, Emanuel Sungging Mumpuni1, Mamat Ruhimat1, Jiyo .1
1.Indonesian National Institute of Aeronautics and Space
Total Solar Eclipse of 9 March 2016 provides a great opportunity to study the interaction between
the Sun and Earth as a complex system. Several team of observers and scientists from National
Institute of Aeronautics and Space will be dispatched to some observing points along the track of
Lunar shadow and its proximity. The main missions are: (1) to study the physical nature of lower
part of Solar corona, (2) to understand the ionospheric disturbance caused by a sudden drop of
Solar radiation to the Earth, and (3) to measure the dynamics of local magnetic field that is
influenced by the ionospheric disturbance. Preliminary result of those observations/experiments
will be discussed in this paper.
Keywords: Solar Eclipse, Corona, Ionosphere, Geomagnet©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P04 -PEM09-P05

Japan Geoscience Union Meeting 2016

RELATIONSHIP OF F LAYER HEIGHT RISE, ESF ONSET TIME, AND AMPLITUDE OF LARGE SCALE WAVE
STRUCTURE*Dyah Rahayu Martiningrum1, Mamoru Yamamoto2, Tatsuhiro Yokoyama3, Prayitno Abadi4, PornchaiSupnithi5, Minh Le Huy6
1.Graduate School of Informatics, Kyoto University, 2.Research Institute for Sustainable
Humanosphere, Kyoto University, 3.National Institute of Informatics and Communications Technology(NICT), Tokyo , 4.Solar-Terrestrial Environment Laboratory (STEL), Nagoya University, 5.Faculty ofEngineering King Mongkut's Institute of Technology, Ladkrabang, Thailand , 6.Institute ofGeophysics Vietnamese Academy of Science and Technology, Vietnam
Under favourable conditions ionospheric plasma at the bottomside of the F-region can become
unstable. Plasma irregularities in several scales produced by Rayleigh-Taylor Instability
mechanism. The recombination process at the E-region after sunset causing the bottom side F-region
electron density gradient become steep. At the same time the eastward electric field intensified
just before it reverses to the westward electric field causing the peak of the F region rise known
as evening prereversal enhancement. The relationship between onset time of field aligned
irregularities related to ESF observed by Equatorial Atmosphere Radar during 2010-2012 with F layerheight rise observed by ionosondes near geomagnetic equator, Chumphon (10.7 N; 99.4 E; 0.86 N) andBac Lieu (9.3 N; 105.7 E; 0.62 N) is discussed in correspondence with growth rate of Rayleigh
Taylor instability development. The field aligned irregularities onset time associated withequatorial spread F observed into two different cases, first case where the EPB/ESF onset time
concurrent with the peak of virtual height of F region - (h’F) time. Second case where the EPB/ESF
onset time happened with delay of more than 30 minutes, with reference to the peak of virtual
height of F region - (h’F) time. The possibility that the amplitude of Large Scale Wave Structure
obtained from GRBR data effects the height of plasma instability development also discussed.
Keywords: F layer height rise, Large Scale Wave Structure, onset time of Equatorial Spread F©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P05 -PEM09-P06

Japan Geoscience Union Meeting 2016

EIA structure and its relation to plasma bubble occurrence along longitude 100° E in 2012
*Kornyanat Watthanasangmechai1, Mamoru Yamamoto2, Tatsuhiro Yokoyama1, Michi Nishioka1, Mamoru Ishii
11.National Institute of Information and Communications Technology, 2.RISH, Kyoto Univ.
To reveal a relationship between EIA structure and plasma bubble occurrence along longitude 100° E
in 2012, the ground-based observations i.e., GNU Radio Beacon Receivers (GRBR), GPS, ionosonde, andEquatorial Atmospheric Radar (EAR), are employed. GRBR is used to capture the precise structure of
EIA. The Rate Of TEC change Index (ROTI) of GPS is used to monitor the plasma bubble occurrence.
Temporal variation of the bottom side of the F layer is measured by the ionosonde. The EAR is for
detecting Field Aligned Irregularities (FAI). In this paper, we will answer the following
questions:(1) What does the EIA structure look like on the plasma bubble on and off day?
(2) Is it necessary that plasma bubble will occur only when EIA is symmetric?
(3) How does the plasma bubble structure look like on the GRBR TEC?
Keywords: EIA, Plasma bubble©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P06 -PEM09-P07

Japan Geoscience Union Meeting 2016

New digital beacon receiver for the study of equatorial ionosphere with satellites TBEx
and FORMOSAT-7/COSMIC-2*Mamoru Yamamoto1, Keiichi Iwata1, Mayumi Matsunaga2, Roland Tsunoda3, Richard Doe3, Tung-Yuan Hsiao4
1.Research Institute for Sustainable Humanosphere, Kyoto University, 2.Graduate School of Scienceand Engineering, Ehime University, 3.SRI International, 4.Hsing Wu University
We have successfully conducted observations of total-electron content (TEC) of the ionosphere using
a satellite-to-ground beacon experiment. A unique dual-band (150/400MHz) digital receiver GRBR (GNURadio Beacon Receiver) was developed for this purpose, which is based on the recent digital-signal
processing technologies. The GRBR network was deployed into the southeast Asian and Pacificregions. By using beacon signals from the low-inclination satellite C/NOFS, we studied longitudinal“large-scale wave structures (LSWS)” in detail as a possible source of equatorial Spread-F (ESF)
events. Now there are 2 new beacon-satellite plans. One is TBEx (Tandem Beacon Explorer), a projectby SRI International, to fly a constellation of two 3U cubesats with triband beacon transmitters.
Another one is a constellation of FORMOSAT-7/COSMIC-2 satellites, also with triband (or quad-band)
beacon transmitters. All of these satellites will be placed into low-inclination orbits by the samelaunch vehicle in late 2016. This launch will provide great opportunities to enhance studies of the
low-latitude ionosphere. Kyoto University, Ehime University and Hsing Wu University are now
developing the new GRBR system that is expected to be used for the TBEx and FORMOSAT-7/COSMIC-2
beacon experiments. In the presentation we will show development of the new beacon receiver
together with plan of observations.
Keywords: Satellite-ground beacon experiment, Ionospheric TEC, COSMIC-2, cubesat, equatorial
ionosphere©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P07 -PEM09-P08

Japan Geoscience Union Meeting 2016

IUGONET data analysis system for a study of coupling processes in the solar-terrestrial
system*Atsuki Shinbori1, Yoshimasa Tanaka2, Norio Umemura3, Yukinobu Koyama4, Shuji Abe6, Masahito Nose7,
Satoru UeNo5
1.Research Institute for Sustainable Humanosphere (RISH), Kyoto University, 2.National Institute ofPolar Research, 3.Institute for Space-Earth Environment research (ISEE), Nagoya University ,4.Transdisciplinary Research Integration Center, 5.Hida Observatory, Kyoto University, 6.
International Center for Space Weather Science and Education (ICSWSE), Kyushu University, 7.WDC for
Geomagnetism, Kyoto University
Various kinds of disturbance phenomenon and long-term variation in the upper atmosphere above 100
km are caused by energy input from solar radiation, solar wind, momenta and energies from the lower
atmosphere via atmospheric waves, and chemical reaction. Such a disturbance phenomenon andlong-term variation observed by various kinds of ground-based and satellite instruments are theresult of such complicated processes. Therefore, in order to understand the mechanisms of these
phenomena detected in this region, researchers need to conduct comprehensive analyses with various
kinds of long-term observation data that have been continued by means of a global network ofradars, magnetometers, optical sensors, helioscopes, etc. The IUGONET (Inter-university Upper
atmosphere Global Observation NETwork) project initiated in 2009 is proposed to establish across-reference system for various kinds of ground-based observation data obtained from different
techniques. The IUGONET participants consist of five universities/institutes: the National
Institute of Polar Research (NIPR), Tohoku University, Nagoya University, Kyoto University, andKyushu University. We have developed a metadata database (MDDB) and IUGONET data analysis software(UDAS) of ground-based observation data managed by these IUGONET universities/institutes with aninternational collaboration in order to promote a comprehensive study on coupling processes in the
Sun-Earth system. MDDB provides researchers in a wide range of disciplines with a seamless data
environment to link observation databases spread across the IUGONET universities/institutes.
Researchers can find basic information of observation data (for example, observation period, data
format, data use policy, instrument, observed region, observation site etc.) from the metadata foreach observation data they are interested in. Recently, the metadata for several satellite
observation data (for example, Akebono, GPS) have been registered to MDDB, and researcher caneasily find the satellite database. UDAS will also be of great help in conducting integrated
analyses and visualization of various kinds of solar-terrestrial observation data to investigate
the long-term variation in the upper atmosphere throughout the Sun-Earth system. UDAS deals with 29
kinds of ground-based observation data provided by the IUGONET universities/institutes. Moreover,the executable file of SPEDAS/UDAS working on Interactive Data Language (IDL)-VM without IDL
license has been released on the SPEDAS website. Owing to the executable file, anybody can use UDAS
and conduct a comprehensive analysis of various kinds of solar and Earth’s atmospheric observation
data. Moreover, in the IUGONET project, in order to enhance an international use of these IUGONET
products, we held a mini-training workshop of how to use the IUGONET MDDB and UDAS at several
developing countries (India, Indonesia, Nigeria, Peru etc). Now, the IUGONET products became an
essential tool to study a mechanism of the solar-terrestrial environmental change. In this talk, we
introduce a brief overview of the IUGONET project, and an application of the IUGONET products totypical examples of upper atmospheric researches.

©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P08 -PEM09-P08

Japan Geoscience Union Meeting 2016

Keywords: Inter-university Upper atmosphere Global Observation NETwork, Upper atmosphere, Metadata
database, IUGONET data analysis software (UDAS), Long-term variation, Ground-based
observation©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P08 -PEM09-P09

Japan Geoscience Union Meeting 2016

Ionospheric weather in the dayside polar cap region*Hitoshi Fujiwara1, Satonori Nozawa2, Yasunobu Ogawa3, Ryuho Kataoka3, Yasunobu Miyoshi4, Hidekatsu
Jin5, Hiroyuki Shinagawa5, Huixin Liu4
1.Faculty of Science and Technology, Seikei University, 2.Institute for Space-Earth Environment
Research, Nagoya University, 3.National Institute of Polar Research, 4.Department of Earth andPlanetary Sciences, Faculty of Sciences, Kyushu University, 5.National Institute of Information andCommunications Technology
Using European incoherent scatter radar (EISCAT) and EISCAT Svalbard radar (ESR),
we have made simultaneous obserbations of the dayside polar cap ionosphere atLongyearbyen and Tromso. Five year observation data show significant disturbancesin the polar cap region northward the ESR site even during geomagnetically quiet
periods. This suggests that the energy input from the magnetosphere would playa fundamental role for dynamics and energetics in the region all the time. In
addition, some researchers suggest effects from the lower atmosphere on thethermospheric variations in the polar region. In order to understand variationsof the polar ionosphere/thermosphere from hour to hour, we should understandenergy flows from the above (magnetosphere) and below (lower atmosphere).
Numerical simulations with a GCM are also essential to do so. In particular,
GCM simulations would reveal physical and chemical processes/mechanisms
to produce the thermoshperic variations while the thermospheric observations
are very few in the dayside.
In the present study, we overview the EISCAT and ESR observations during 2011-2016.
The recent progress of our understandings from comprehensive observations andGCM simulations are also shown.
Keywords: ionosphere, thermosphere, EISCAT, GCM, simulation©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P09 -PEM09-P10

Japan Geoscience Union Meeting 2016

Using Vondrak smoothing method to improve the prediction of Sunspot Maximum*ZQ Yin1, YB Han1
1.NAO. CAS. CHINA
About 11-year cycle of solar activity is the most significant quasi-periodic component, whichlargely represents the strength of solar activity and is the basis for dividing solar cycle. Many
studies have proven that solar activity can affect the developing process of many phenomena on the
Earth, such as climate, geophysical and marine changes etc. In order to meet the demands ofheliophysics and solar activity variation characteristics studies, especially, for the demand of
Solar Terrestrial Relations studies and space science development, studies of solar activity
characteristics and prediction are getting more attention. Some authors summerized a variety ofmethods for the maximum predictions of 22nd, 23rd, 24th solar cycles, the incomplete statistics are
63, 54 and 75 cases respectively, results of the methods, which the difference between forecastingand observed values within the range of ±15%, are 27.0%, 25.9% and 24.3% respectively. Using the 13
points smoothed value of monthly sunspot numbers, we studied correlation between sunspot number
rising rate of the first 24 months of the solar cycle and the coming cycle maximum, publishedforecasting result that the maximum value was 139.2 ±18.8 for 23rd solar cycle (Han et al., 2000),
and the observed value is 120.8, the error is about 15.2%. The present paper introduces our
improved forecasting methods. Vondrak smoothing method is used to deal with the monthly sunspot
numbers. It is studied that the relationship between the rise rate of earlier months of sunspot
numbers of this smoothed sequence and the coming maximum value in each solar cycles. The results
show that the first 22, 23, 24 months rise rate of sunspot numbers are highly related with thecoming maximum values, and simulated prediction of maximum for 22~24 cycles show that using the
22-month rise rate of three solar cycles, the maximum forecasting error is about 13.2%, using
23-month rise rate, the maximum error is about 11.2%, while using 24-month rise rate, the maximum
error is only about 9.3%. The new method can make the forecasting time in advance at least half ayear than the common method using 13 points monthly smoothed value, which the difference between
prediction and observed values within the range of ±15%. The results also show that the maximum
error is about 20% if we use 18-month rise rate, and it can make the forecasting time in advance atleast one year than the common method using 13 points monthly smoothed value.
Keywords: Sunspot Maximum, Prediction©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P10 -PEM09-P11

Japan Geoscience Union Meeting 2016

D- and E-region ISR spectra measured with EISCAT radars*Yasunobu Ogawa1, Satonori Nozawa2, Ingemar Häggström 3
1.National Institute of Polar Research, 2.Institute for Space-Earth Environmental Research, Nagoya
University , 3.EISCAT Headquarters
The energy from the solar wind is mainly transported to the polar upper atmosphere and causes
various phenomena such as auroras characterized by their rapid variability in time and space.
Incoherent scatter radar (ISR) located in high latitude is one of the most powerful tools toinvestigate generation mechanisms of such phenomena and their effects on the atmosphere. The ISR
basically gives information of plasma parameters between the bottom-side and topside ionospheres.
However, the ISR has several unavoidable limitations to derive ionospheric parameters in the E- andD-region ionospheres, due to limited information of the ISR spectra.
We have investigated ISR spectra in the D- and E-region using the latest techniques of the EISCAT
UHF and VHF radars located in Tromsø. Previous studies indicate that the EISCAT UHF and VHF radars
have limitations of plasma parameter derivation below 90 and 100 km altitudes, respectively. We
show lower limits of reliable plasma parameter derivation using the latest pulse coding techniquesof the EISCAT radars. Based on the knowledge and experience of the current EISCAT radarobservations, we will discuss possibility and limitation of future E- and D-region observations of
the EISCAT_3D radar.
Keywords: ionosphere, Incoherent scatter radar, plasma©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P11 -PEM09-P12

Japan Geoscience Union Meeting 2016

National/International joint studies with the Tromsø OMTI for studying the polar upper
atmosphere*Shin-ichiro Oyama1, Kazuo Shiokawa1, Satonori Nozawa1, Yuichi Otsuka1, Yoshizumi Miyoshi1, Esa
Turunen2, Anita Aikio3, Lei Cai3
1.Institute for Space-Earth Environmental Research, Nagoya University, 2.Sodankyla GeophysicalObservatory, University of Oulu, 3.University of Oulu
Institute for Space-Earth Environmental Research (ISEE) has been operating various kinds of optical
instruments for more than 15 years at the Tromsø European Incoherent Scatter (EISCAT) radar site in
Norway (Geographic: 69.6N, 19.2E, Geomagnetic: 66.7N, 102.2E, L=6.4), which is one of thestate-of-art observatories at high latitudes. In January 2009, we began operation of a Fabry-Perot
interferometer (FPI) and an all-sky type cooled CCD camera (ASC) at dark nights of the wintermonths (from middle of September to early April in most years). The FPI (#01 of the Optical
Mesosphere Thermosphere Imagers (OMTIs)) measures airglow and aurora by rotationally changing
optical wavelengths of 557.7 and 630.0 nm for most of the nights in order to derive thethermospheric wind and temperature. Four cardinal points with zenith angle of 45 or 15 and thegeographic vertical (i.e. five directions) are measured sequentially. The combination of data fromthe four cardinal positions provides the horizontal components of the neutral wind velocity. The
all-sky camera (camera #12 of OMTIs) includes a filter wheel used to select one of the six opticalfilters (channel 1: 557.7 nm, channel 2: 630.0 nm, channel 3: OH band (720 ∼1000 nm), channel 4:589.3 nm, channel 5: 572.5 nm, and channel 6: 732.0 nm). While the exposure time for FPI and ASC
measurements is tuned as good for individual scientific objectives, in the case of FPI typicalvalues are 1 minute or 15 seconds for airglow and auroral measurements, respectively, and in thecase of ASC those are about 30 and 10 seconds for the individual targets, respectively. However,shorter exposure times have been applied for measuring fine structures of aurora. Other optical
instruments such as photometer, digital camera, and all-sky camera (486.1 nm) are collocated with
the OMTI FPI and ASC. Data from these instruments have been provided to national and international
researching activities. For example, the FPI was operated together with the EISCAT radars as a key
diagnostic instrument for providing thermospheric parameters during periods of geomagnetic
disturbances. Integrated studies of the FPI-measured wind and the EISCAT-measured ionosphericparameters (including full vector of the electric field) improve our understanding of the energy
dissipation and momentum transfer processes and of polar ionospheric/thermospheric responses to thesolar-wind change. Effects of energetic electron precipitation (EEP) on the atmosphere are also
analyzed using data from our optical instruments and EISCAT radars. This topic is proceeded undercollaboration with Chemical Aeronomy in the Mesosphere and Ozone in the Stratosphere (CHAMOS)
group. Sodankylä Ion Chemistry (SIC) model, which is used in the group, is a powerful tool for
estimating atmospheric responses to EEP, in particular variations in the atmospheric minor
components such as NOx, HOx, and O3. Ionospheric and atmospheric variations associated with EEP will
be one of the important scientific objectives in the ERG project. This presentation will make abrief introduction of a few results from the national/international join studies.
Keywords: Aurora, Airglow, Optical instrument, Ionosphere, Thermosphere, High latitude©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P12 -PEM09-P13

Japan Geoscience Union Meeting 2016

Study on pulsating aurora-induced sodium density variation: high-speed sodium lidar
observation*Toru Takahashi1, Takuo T. Tsuda2, Keisuke Hosokawa2, Satonori Nozawa3, Yasunobu Ogawa4, Takuya
Kawahara5, Norihito Saito6, Satoshi Wada6, Tetsuya Kawabata3, Chris Hall7
1.Center for Space Science and Radio Engineering, The University of Electro-communications,
2.Department of Communication Engineering and Informatics, University of Electro-Communications,
3.Institute for Space-Earth Environment Research, 4.National Institute of Polar Research, 5.Facultyof Engineering, Shinshu University, 6.RIKEN, 7.The Arctic University of Norway
We have been made observations of the sodium density, neutral temperature and wind velocity in thepolar MLT region since October 2010 by a sodium lidar installed at Tromsø, Norway. By using thesodium lidar together with EISCAT radars, MF radar, meteor radar, FPI, and aurora imagers, we havestudied and reported several results, such as the upward propagating gravity wave, the comparisonof the neutral temperature and ion temperature, and the generation mechanism of the sporadic sodium
layer, whose time scale are a few minutes to several hours.
Energetic electrons, which can be the source for the pulsating aurora, release their energy bycollision with neural particles below 100 km. The periods of the pulsating aurora are seconds to
sub-seconds. This implies that the neutral atmosphere may change in the similar time scales interms of composition, temperature, and wind velocity by the energy input from the energetic
particles. To date, however, there are no observations of the neutral atmosphere in these timescale at polar region as far as we knows. Thus, the high-speed observation would be essentially
important for understanding in the neutral atmospheric response during the pulsating aurora.
In this study, we have been made an upgrade in the data recording and laser control system for theTromsø sodium lidar system. We have installed the new recording system in January 2016, and alreadystarted test observations. Currently, we are successful to make the sodium density observation withtime resolution of seconds to sub-seconds. In this presentation, we will introduce the high-time
resolution data in the sodium density obtained from January to March 2016.
Keywords: sodium lidar, pulsating aurora©2016. Japan Geoscience Union. All Right Reserved.

- PEM09-P13 -PEM09-P14

Japan Geoscience Union Meeting 2016

Comparison study between coherent radar echo and empirically-modeled electron density inthe mesosphere based on the PANSY radar*Takanori Nishiyama1,2, Kaoru Sato3, Takuji Nakamura1,2, Masaki Tsutsumi1,2, Toru Sato4, Koji
Nishimura1,2, Yoshimasa Tanaka1,2, Yoshihiro Tomikawa1,2, Masashi Kohma3
1.National Institute of Polar Research, 2.SOKENDAI (The Graduate University for Advanced Studies),
3.The University of Tokyo, 4.Kyoto University
Polar Mesosphere Winter Echo (PMWE) is known as back scatter echo from 55 to 85 km in themesosphere, and it has been observed by MST and IS radar in polar region during non-summer period.
Since density of free electrons as scatterer is low in the dark mesosphere during winter, it issuggested that PMWE requires strong ionization of neutral atmosphere associated with Energetic
Particles Precipitations (EPPs) during Solar Proton Events [Kirkwood et al., 2002] or during
geomagnetically disturbed periods [Nishiyama et al., 2015]. However, studies on relationshipbetween occurrence of PMWE and background electron density has been limited yet [Lübken et al.,2006], partly because the PMWE occurrence rate is known to be quite low (2.9%) [Zeller et al.,2006].
The PANSY (Program of the Antarctic Syowa MST/IS) radar, which is the largest MST radar in
Antarctica, observed many PMWE events since it has started mesosphere observations in June 2012. We
established an application method of the PANSY radar as riometer, which makes it possible toestimate Cosmic Noise Absorptions (CNA) as proxy of relative variations on background electron
density. In addition, electron density profiles from 60 to 150 km altitude are calculated by
Ionospheric Model for the Auroral Zone (IMAZ) [McKinnell and Friedrich, 2007] and CNA estimated by
the PANSY radar.
In this presentation, we would like to focus on strong PMWE during two big geomagnetic storm
events, St. Patrick’s Day and the Summer Solstice 2015 Event, in oreder to compare observed PMWE
characteristics to model background electron density. On March 19 and 22, recovery phase of St.
Patrick’s Day Storm, sudden PMWE intensification was detected near 60 km by the PANSY radar. At thesame time, strong Cosmic Noise Absorptions (CNA) of ~ 0.8 dB and 1.0 dB were measured,
respectively. However, calculated elctron density profiles did not necessarily demonstrate highelecetron density at the altitude where the PMWE intensifications were observed. On June 22, theSummer Solstice 2015 Event, strong nighttime PMWE near 80 km was detected around 16 UT, which isequal to 19 LT at Syowa station. Since PMWE observations are primarily confined to daytime becauseof relatively abundant free electrons in the illuminated mesosphere, this strong and long-lived
nighttime PMWE implies that EPPs related to the storm caused the sporadic ionization sufficient for
PMWE even in dark mesosphere. The modeled electron density profile agreed with the occurrence of
the PMWE, showing density enehancement of 109 - 1010 cm-3 from 60 to 80 km altitude. The difference
between the above two events is thought to be caused by overestimations of CNA in St. Patrick’s Day
Storm, which leads to underestimation of modeled electron density. We are going to validate CNA
estimated by the PANSY radar and discuss about discrepansy between modeled elecron density and PMWE
in detail.
Keywords: MST radar, Mesosphere, Polar Mesosphere Winter Echo, Ionopheric D-region©2016. Japan Geoscience Union. All Right Reserved.

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Japan Geoscience Union Meeting 2016

Antarctic Syowa station SENSU SuperDARN radars in the 9th phase of JARE Atarctic project(2016-2023)*Akira Sessai Yukimatu1,2
1.National Institute of Polar Research, 2.Dept. Polar Sci., SOKENDAI (The Graduate University for
Advanced Studies)
Syowa SENSU SuperDARN HF radars are important components of SuperDARN, the international HF radars
network since 1995 and have significantly contributed to understanding not only
magnetosphere-ionosphere coupling system but also MLT region dynamics. As SuperDARN radars wereoriginally designed to reveal global polar ionospheric plasma convection patterns in bothhemispheres in real time, its spatial resolution has been relatively low. As the number of newscientific targets like comparison with mid and small scale aurora phenomena, meso scale transientphenomena, elementary generation and decay process of field aligned irregularities, PMSEs and fineheight profile of neutral wind has been increasing, higher spatial and temporal resolution
observations have been essentially desired and of great importance. Imaging radar technique has
been tried to be applied and developed to overcome these issues. We show the current status of the
SENSU imaging radar system, and will discuss particularly on the scientific targets including
coming JARE (Japanese Antarctic Research Expedition) project phase IX (2016-2023) and the future
perspectives which can be revealed by this new technique using SuperDARN. In the phase IX JARE
project. Our research group has proposed a research program to JARE project focused especially on
possible grand minimum influences on geospace environment and inner magnetospheric dynamics and thedetail plans including collaboration with other satellite and ground-based observation and its
contribution to the project "Study of coupling processes in solar-terrestrial system" as well as
the international VarSITI program will be discussed.
Keywords: SuperDARN, Antarctic Syowa Station, Japanese Antarctic Research Expedition project phase
9, Grand minimum, inner magnetosphere, VarSITI©2016. Japan Geoscience Union. All Right Reserved.

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