資料8-G
Commission G Report
November 6, 2012
Archived by Mamoru Yamamoto, Kyoto Univ.
1. Research Report
1.1. Ionospheric disturbances after the intense earthquake and tsunami (Takuya Tsugawa, NICT)
Ionospheric disturbances following the intense earthquake and tsunami such as the 2011 off the Pacificcoast of Tohoku Earthquake (2011 Tohoku EQ) were studied by GPS-TEC and ionosonde observations inJapan and numerical simulations. All the details of post-seismic ionospheric disturbances were firstobserved by a high-resolution two-dimensional GPS-TEC observation in Japan (Tsugawa et al., 2011).
The initial ionospheric disturbance appeared as sudden TEC depletion about seven minutes after theearthquake onset near the epicenter (Saito et al., 2011; Kakinami et al., 2012). In the vicinity of theepicenter, short-period oscillations with a period of about 4 minutes were also observed (Saito et al., 2011).
Off the epicenter, zonally-extended band-like structures and concentric wave trains appeared in thedetrended TEC maps about 15 minutes after the earthquake onset. The former band-like structure traveled
equatorward and also appeared in Taiwan (Chen et al., 2011). The latter concentric waves with longer
wavelengths and larger propagation velocities appeared earlier (Tsugawa et al., 2011). The center of the
TEC depletion and concentric waves, termed “ionospheric epicenter”, was located about 170 km from theepicenter in the southeast direction and consistent with estimated areas of the tsunami source. These
ionospheric disturbances were reproduced by numerical simulation with a time-dependent, twodimensional, nonlinear, non-hydrostatic, compressible and neutral numerical model (Matsumura et al.,2011). Based on these observation and simulation results, it is considered that the first fast-propagating
ionospheric concentric wave with the propagation velocity of about 3.5 km/s was caused by the acoustic
wave generated from the propagating Rayleigh wave. The second and following concentric waves would
correspond to the atmospheric gravity waves (AGWs) propagating in the ionosphere. These AGWs are
considered to be generated at the tsunami wavefronts and at the lower ionosphere above the tsunami
source. Unusual multiple-cusp signature (MCS) was observed in ionograms obtained by four ionosonde
stations in Japan about 15 minutes after the earthquake onset (Maruyama et al., 2011). The real height
analysis of the MCS showed a vertical ionospheric structure with a scale size of 20∼30 km, indicating
acoustic wave generated from the propagating Rayleigh wave. The specific conditions of MCS appearance
were statistically studied based on MCS events observed in 8 or 43 earthquakes with a seismic magnitudeof 8.0 or greater during the period 1957 to 2011 (Maruyama et al., 2012).
1.2. Sounding rocket experiment (Keigo Ishisaka, Toyama Pref. Univ.)
Ionospheric Radio Wave: S-310-40 sounding rocket experiment was carried out at Uchinoura Space
Center (USC) at 23:48 JST on 19 December, 2011. The purpose of this experiment is the investigation ofcharacteristics of radio wave propagation in the ionosphere and the estimation of electron density structurein the lower ionosphere, when the intensity of radio wave measured on the ground was attenuate atnighttime. In order to measure the radio waves, a LF/MF band radio receiver (LMR) is installed on thesounding rocket. The LMR measured the propagation characteristics of four radio waves at frequencies of
60 kHz, 405 kHz, 666 kHz and 873 kHz in the region from the ground to the lower ionosphere. The LMR
could measure the relative attenuation of radio waves from the ground up to the ionosphere. Furthermore
the loop antenna consists of three loop antennas in order to measure three components of four radio waves.

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Although the attenuation of intensity is seen near an altitude of 100 km, the amount of attenuation is lessthan usual. 100 dB or more is decreased in usual. Such observations are not obtained by past rocket
experiments. We investigate the unusual propagation characteristic of radio waves in the ionosphere at
winter nighttime. Then we will obtain the 3-dimensional structure of electron density in the lower
ionosphere by measuring the intensity of radio waves that propagate from the three different directions.
Electric field measurement with double probe: S-520-26 sounding rocket experiment was carried out at
Uchinoura Space Center (USC) in Japan at 5:51 JST on 12 January, 2012. The purpose of this experimentis the investigation of the bonding process between the atmospheres and the plasma in the thermosphere.
S-520-26 sounding rocket reached to an altitude of 298 km at 278 seconds after the launch. The S-520-26
payload was equipped with Electric Field Detector (EFD) with a two set of orthogonal double probes tomeasure both DC and AC less than 200 Hz electric fields in the spin plane of the payload by using the
double probe method. Results of DC electric fields measured by the EFD have the large sine waves that
result from the payload rotation at the spin period. The largest contribution to the electric fieldmeasurements by double probes moving through the ionosphere at mid-latitudes is that due to the vxBfields created by their motion across the ambient magnetic field, where v is the rocket velocity in the
Earth-fixed reference frame and B is the ambient magnetic field. The sum of the squares of the twocomponents represents the magnitude of the DC electric field in the spin plane of the payload. These data
reveal abrupt, large-scale variations which can immediately be attributed to changes in the geophysicalelectric field since the vxB fields are slowly varying. The sum of the squares data also reveals
contributions at the spin frequency and its harmonics. These contributions result primarily from distortionsof the waveforms in the raw data.
1.3. Airglow imaging and tweak experiment (Kazuo Shiokawa, Nagoya Univ.)
Shiokawa et al. (2012) reported the rapid oscillating motion of nighttime medium-scale travelingionospheric disturbances (MSTIDs) associated with an auroral brightening, based on airglow imaging
observations at Tromso (magnetic latitude: 67.1N), Norway. This observation indicates that the MSTID
oscillation was linked to auroral electric field in the ionosphere, implying that the observed MSTIDs areionospheric plasma structures. They suggest that the observed MSTIDs were created by atmosphericgravity waves at the beginning, left as fossil plasma structures even after the gravity wave packet
dissipated in the thermosphere.
Ohya et al. (2012) reported multi-point observations of daytime tweek atmospherics during the solar
eclipse of 22 July 2009 at Moshiri and Kagoshima, Japan, where the magnitudes of the solar eclipse were
only 0.458 and 0.966, respectively. The wide range of estimated tweek reflection heights at Kagoshima
also suggests a difference in electron density in the D- and lower E-regions between total and partial solar
eclipses.
1.4. Polar cap studies (Keisuke Hosokawa, Univ. of Electro-Communications)
Several studies on various phenomena in the polar cap ionosphere have been conducted by using an allsky airglow imager (ASI) of OMTIs (Optical Mesosphere Thermosphere Imagers; operated by Nagoya
University) at Resolute Bay (74.73N, 265.07E). Hosokawa et al. (2011a) observed an unusual event inwhich a polar cap ionization patch stopped its anti-sunward motion and stayed within the field-of-view for
more than one hour. When the patch stagnated, its luminosity decreased gradually, which allows them toinvestigate how the patch plasma decayed in a quantitative manner. The decay of the patch can bequantitatively explained by the loss through recombinations of O+ with ambient N2 and O2 molecules, if

2we assume the altitude of the optical patch to be around 295 km. The derived altitude of the patch around295 km is much higher than the nominal value at 235 km obtained from the MSIS-E90/IRI2007 models,
which suggests that we should employ higher emission altitude when we investigate optical patchestransported deep into the nightside polar cap. Hosokawa et al. (2011b) carried out a statistics of motion ofpolar cap arcs (i.e., auroral arcs in the polar cap latitudes) by using 5 years of optical data from Resolute
Bay. They identified 743 arcs by using an automated arc detection algorithm, and statistically examined
their moving velocities. They showed that polar cap arcs fall into two distinct categories, the IMFdependent and IMF-independent (IMF: Interplanetary Magnetic Field) arcs. This implies that themechanism causing the arc motion is fundamentally different between these two types of arc. Thus, theirmagnetospheric source could also be different.
Another all-sky airglow imager has been operational in Longyeabyen, Norway (78.2N, 15.6E; AACGM
latitude 75.3) since October 2011 by University of Electro-Communications. The ASI is equipped with an
EMCCD camera whose imaging part has 512x512 pixels. The imager has two different passband
interference filters for airglow measurements, one at 630.0 nm and the other at 557.7 nm, which enables us
to study various phenomena in the polar cap ionosphere, such as cusp aurora, polar cap aurora and polar
cap patches. The exposure time for 630.0 nm emissions is 4.0 s. Every 56 s (= 14 x 4 s) 557.7 nm
emissions are observed with an exposure time of 1.0 s by rotating the filter turret. Background continuum
emission from the sky is sampled every 10 min at a wavelength of 572.5 nm and is used to derive theabsolute intensity of the airglow lines. Optical images obtained by this ASI will be used for better
understanding the dynamic nature of polar cap ionospheric phenomena such as polar cap patches and polar
cap arcs in near future.
1.5. EISCAT radar experiment and related studies (Satonori Nozawa, Nagoya Univ.)
By using EISCAT radars as well as instruments operated in northern Scandinavia, we have conductedfollowing studies: (1) Lower thermosphere/Mesosphere wind was investigated by the new meteor radar at
Bear Island (74.5ºN, 19.0ºE) that started operation on November 2007. Seasonal variations of mean wind,
diurnal and semidiurnal tides, and quasi-two day wave are found to be similar to those at Tromsø (69.6ºN,
19.2ºN). (2) First observations of auroral roar emissions near 4 times fce (electron cyclotron frequency)
were conducted at Longyearbyen (78.2ºN, 16.0ºE). 4 fce roar emissions were detected from 5.27 to 5.70
MHz during moderate geomagnetic disturbances in 22 days between May and September 2011 only fromnoon to evening, while no event occurred during the winter season. The observations support the idea
expanded from the most commonly accepted generation mechanism of 2 fce and 3 fce roar: the origin of 4
fce roar is upper hybrid waves favorably generated under the condition of fUH (upper hybrid resonancefrequency) equal to 4 fce in the auroral F-region. (3) Variations of ion temperatures at Longyearbyen were
investigated using IPY long-run data obtained by EISCAT Svalbard radar and predictions by GCM. The
ion temperatures show significant seasonal variations. The amplitudes of the local time and seasonalvariations observed are much larger than the ones predicted by the IRI-2007 model. This study suggested
significant heat sources in the polar cap region even under solar minimum and geomagnetically quiet
conditions. (4) Fine structure of a sporadic sodium layer (SSL) was observed by a new sodium LIDAR,
which started operation on October 1, 2010, at Tromsø on January 11, 2011. The sodium lidar
measurement with 5-sec time resolution revealed the details of dramatic sodium-density increase as well
as short-period wavelike structure in the SSL. The calculated power spectral densities are well represented
by power laws, implying the presence of the short-period waves and turbulence in the frequency range of
10-4 – 10-1 Hz.

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1.6. Equatorial Atmosphere Radar (Mamoru Yamamoto, Kyoto Univ.)
Equatorial Atmosphere Radar (EAR) is a big atmospheric radar located in West Sumatra, Indonesia. The
EAR was established in June 2001, and has continued long-term observations. Research Institute for
Sustainable Humanosphere (RISH), Kyoto University and National Institute of Aeronautics and Space(LAPAN) of Indonesia hold the 10th anniversary ceremony and symposium on September 22-23, 2011, at
Jakarta. The ceremony was attended by the Minister of Research and Technology of Indonesia, theMinister of the Embassy of Japan, and the representative from the Ministry of Education, Culture, Sports,
Science Technology (MEXT), and the Vice President of Kyoto University.
The research project “Research Enhancement and System Establishment for Space Weather in Indonesia”
is conducted during FY 2010-2012 under the framework of “Strategic Funds for the Promotion of Scienceand Technology” by MEXT (operation by Japan Science and Technology Agency (JST)). This is a joint
project with RISH, Solar-Terrestrial Environmental Laboratory (STEL), Nagoya University, and National
Insititute for Information and Communications Technology (NICT). The counterpart in Indonesia is
LAPAN. Space weather is a program to observe, assess, and forecast the space environment, and regional
observations and studies of the ionosphere are very important. Experiments for the project is not limited inIndonesia, but spread over southeast Asian countries. RISH and LAPAN started the EAR long-duration
observation of the equatorial Spread-F (ESF) since July 2010 and archived huge amount of data for ESF
occurrence and their spatial-time structures. They also expand observation network of dual-band satellite
beacon receivers for the study of ionospheric structures. STEL started the Fabry-Perot interferometry
experiment at the EAR site and Chiang Mai (Thailand) to measure thermospheric winds at thegeomagnetically conjugate points. NICT keeps operation of SEALION ionosonde network, and collecting
GPS-TEC data from the region of southeast Asia.
1.7. Magnetic Data Acquisition System (MAGDAS) and related studies (Huixin Liu, Kyushu Univ.)
MAGDAS is the world network of magnetometer developed and maintained by International Center forSpace Weather Science and Education (ICSWSE), Kyushu University. MAGDAS network and its
observations are well maintained during this period. New installation of fluxgate magnetometer(MAGDAS 9) in 2012 is listed as follows.
- Jayapura, Indonesia. - Sicincin, Sumatra, Indonesia- Bengkulu, Sumatra, Indonesia- Liwa, Sumatra, Indonesia(Above three are for earthquake investigations in Sumatra).
- Jerusalem, Ecuador.
Many studies of atmospheric tides, sudden stratospheric warming, various ionospheric phenomena, andthermosphere-ionosphere coupling are published in international journals.
2. Meetings
39th COSPAR Scientific Assembly, Mysore, India, July 14-22, 20122012 ISWI and MAGDAS School on Space Sciences, Puncak, Indonesia, September 17-26, 20124

3. Publication list
Ionospheric disturbances after the intense earthquake and tsunami (related to 1.1)
Chen, C. H., A. Saito, C. H. Lin, J. Y. Liu, H. F. Tsai, T. Tsugawa, Y. Otsuka, M. Nishioka, and M.
Matsumura, Long-distance propagation of ionospheric disturbance generated by the 2011 off the Pacificcoast of Tohoku Earthquake, Earth, Planets, and Space, 63, 881-884, 2011.
Kakinami, Y., M. Kamogawa, Y. Tanioka, S. Watanabe, A. R. Gusman, J.-Y. Liu, Y. Watanabe, and T. Mogi,
Tsunamigenic ionospheric hole, Geophys. Res. Lett., 39, L00G27, doi:10.1029/2011GL050159, 2012.
Maruyama, T., T. Tsugawa, H. Kato, A. Saito, Y. Otsuka, and M. Nishioka, Ionospheric multiple
stratifications and irregularities induced by the 2011 off the Pacific coast of Tohoku Earthquake, Earth,Planets, and Space, 63, 869-873, 2011.
Maruyama, T., M. Ishii, T. Tsugawa, H. Kato, and M. Nishioka, Rayleigh wave signature in ionograms
induced by strong earthquakes, J. Geophys. Res., 117, A08306, doi:10.1029/2012JA017952, 2012.
Matsumura, M., A. Saito, T. Iyemori, H. Shinagawa, T. Tsugawa, Y. Otsuka, M. Nishioka, and C. H. Chen,
Numerical simulations of atmospheric waves excited by the 2011 off the Pacific coast of Tohoku
Earthquake, Earth, Planets, and Space, 63, 885-889, 2011.
Saito, A., T. Tsugawa, Y. Otsuka, M. Nishioka, T. Iyemori, M. Matsumura, S. Saito, C. H. Chen, Y. Goi, and
N. Choosakul, Acoustic resonance and plasma depletion detected by GPS total electron content
observation after the 2011 off the Pacific coast of Tohoku Earthquake, Earth, Planets, and Space, 63, 863867, 2011.
Tsugawa, T., A. Saito, Y. Otsuka, M. Nishioka, T. Maruyama, H. Kato, T. Nagatsuma, and K. T. Murata,
Ionospheric disturbances detected by GPS total electron content observation after the 2011 off the Pacificcoast of Tohoku Earthquake, Earth, Planets, and Space, 63, 875-879, 2011.
Airglow imaging and tweak experiment (Related 1.3)
Shiokawa, K., M. Mori, Y. Otsuka, S. Oyama, and S. Nozawa, Motion of high-latitude nighttime mediumscale traveling ionospheric disturbances associated with auroral brightening, J. Geophys. Res., 117,
A10316, doi:10.1029/2012JA017928, 2012.
Ohya, H., F. Tsuchiya, H. Nakata, K. Shiokawa, Y. Miyoshi, K. Yamashita, and Y. Takahashi, Reflection
height of daytime tweek atmospherics during the solar eclipse of 22 July 2009, J. Geophys. Res., in press,
doi:10.1029/2012ja018151, 2012.
Polar cap studies (Related to 1.4)
Hosokawa, K., J. I. Moen, K. Shiokawa, and Y. Otsuka, Decay of polar cap patch, Journal of GeophysicalResearch, 116, doi:10.1029/2010JA016297, 2011a.
Hosokawa, K., J. I. Moen, K. Shiokawa, and Y. Otsuka, Motion of polar cap arcs, Journal of GeophysicalResearch, 116, doi:10.1029/2010JA015906, 2011b.
EISCAT radar experiment and related studies (Related to 1.5)
Nozawa et al., JASTP, 10.1016/j.jastp.2012.05.002, 2012. [Referred as (1) in Subsection 1.5]
Sato et al., Geophys. Res. Lett., vol 39, L07101, doi:10.1029/2012GL051205, 2012. [(2) in Subsection 1.5]
Fujiwara et al., Earth, Planet and Space, vol 64, 459-465, 2012. [(3) in Subsection 1.5]
Tsuda et al., GRL, vol. 38, L18102, doi:10.1029/2011GL048685, 2011. [(4) in Subsection 1.5]
Equatorial Atmosphere Radar (Related 1.6)
Sudarsanam, Tulasi Ram, M. Yamamoto, R. T. Tsunoda and S. V. Thampi, On the application of differential
phase measurements to study the zonal large scale wave structure (LSWS) in the ionospheric electron
content, Radio Science, 47, RS2001, doi:10.1029/2011RS004870, 2012.
Otsuka, Y., K. Shiokawa, and T. Ogawa, Disappearance of equatorial plasma bubble after interaction with
mid-latitude medium-scale traveling ionospheric disturbance, Geophys. Res. Lett., 39, L14105,
doi:10.1029/2012GL052286, 2012.

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Otsuka, Y., Seasonal and Local Time Variations of E-Region Field-Aligned Irregularities Observed with 30.8MHz Radar at Kototabang, Indonesia, Special issue of International Journal of Geophysics, "Low-latitude
Mesosphere, Thermosphere and Ionosphere", vol. 2012, 695793, doi:10.1155/2012/695793, 2012.
Otsuka, Y., K. Shiokawa, M. Nishioka and Effendy, VHF Radar Observations of Post-Midnight F-Region
Field-Aligned Irregularities over Indonesia during Solar Minimum, Indian Journal of Radio and Space
Physics (IJRSP), 41, 199-207, 2012.
Sudarsanam, Tulasi Ram, M. Yamamoto, B. Veenadhari and Sandeep Kumar, Corotating Interaction Regions(CIRs) at sub-harmonic solar rotational periods and their impact on Ionosphere-Thermosphere system
during the extreme low solar activity year, 2008, Indian Journal of Radio and Space Physics, 2011-SPIJRSP-001, 41, 294-305, 2012.
Smitha V. Thampi, and Mamoru Yamamoto, Evolution of plasma bubbles over Vietnam region observed using
the CERTO beacon on 1 board C/NOFS satellite, Indian Journal of Radio and Space Physics, 2011-SPIJRSP-004, 41, 233-239, 2012.
Wichaipanich, N., P. Supnithi, T. Tsugawa, and T. Maruyama, Thailand low and equatorial F2-layer peakelectron density and comparison with IRI-2007 model, Earth, Planets, and Space, 64, 485-491, 2012.
Watthanasangmechai, K., P. Supnithi, S. Lerkvaranyu, T. Tsugawa, T. Nagatsuma, and T. Maruyama, TEC
prediction with neural network for equatorial latitude station in Thailand, Earth, Planets, and Space, 64,
473-483, 2012.
T. Adachi, Y. Otsuka, M. Yamaoka, M. Yamamoto, K. Shiokawa, A. B. Chen, and R.-R. Hsu, First satelliteimaging observation of medium-scale traveling ionospheric disturbances by FORMOSAT-2/ISUAL,
Geophys. Res. Lett., 38, L04101, doi:10.1029/2010GL046268, 2011.
N. Balan, M. Yamamoto, V. Sreeja, I. S. Batista, K. J. W. Lynn, M. A. Abdu, S. Ravindran, T. Kikuchi, Y.
Otsuka, K. Shiokawa, and S. Alex, A statistical study of the response of dayside equatorial F2 layer to themain phase of intense geomagnetic storms, J. Geophys. Res., 116, A03323, doi:10.1029/2010JA016001,
2011.
N. Balan, M. Yamamoto, J. Y. Liu, Y. Otsuka, H. Liu, and H. Luhr, New aspects of thermospheric andionospheric storms revealed by CHAMP, J. Geophys. Res., 116, A07305, doi:10.1029/2010JA016399,
2011.
S. V. Thampi, M. Yamamoto, C. Lin, and H. Liu, Comparison of FORMOSAT-3/COSMIC radio occultation
measurements with radio tomography, Radio Sci., 46, RS3001, doi:10.1029/2010RS004431, 2011.
T. Yokoyama, M. Yamamoto, Y. Otsuka, M. Nishioka, T. Tsugawa, S. Watanabe, and R. F. Pfaff, On postmidnight low-latitude ionospheric irregularities during solar minimum: 1. Equatorial Atmosphere Radarand GPS-TEC observations in Indonesia, J. Geophys. Res., 116, A11325, doi:10.1029/2011JA016797,
2011.
T. Yokoyama, R. F. Pfaff, P. A. Roddy, M. Yamamoto, and Y. Otsuka, On post-midnight low-latitude
ionospheric irregularities during solar minimum: 2. C/NOFS observations and comparison with
Equatorial Atmosphere Radar, J. Geophys. Res., 116, A11326, doi:10.1029/2011JA016798, 2011.
Makela, J., and Y. Otsuka, Overview of Nighttime Ionospheric Instabilities at Low- and Mid-Latitudes:
Coupling Aspects Resulting in Structuring at the Mesoscale, Space Sci. Rev., DOI 10.1007/s11214-0119816-6, 2011.
Tsunoda, R. T., M. Yamamoto, T. Tsugawa, T. L. Hoang, S. Tulasi Ram, S. V. Thampi, H. D. Chau, and T.
Nagatsuma, On seeding, large-scale wave structure, equatorial spread F, and scintillations over Vietnam,
Geophysical Research Letters, 38, L20102, doi:10.1029/2011GL049173, 2011.
Lynn, K. J. W., Y. Otsuka, and K. Shiokawa, Simultaneous observations at Darwin of equatorial bubbles byionosonde-based range/time displays and airglow imaging, Geophys. Res. Lett., 38, 23,
doi:10.1029/2011GL049856, 2011.
Kenpankho, P., K. Watthanasangmechai, P. Supnithi, T. Tsugawa, and T. Maruyama, Comparison of GPS
TEC measurements with IRI TEC prediction at an equatorial latitude station, Chumphon, Thailand, Earth,Planets, and Space, 63, 365-370, 2011.
Kenpankho, P., P. Supnithi, T. Tsugawa, and T. Maruyama, Variation of ionospheric slab thickness
observations at Chumphon equatorial magnetic location, Earth, Planets, and Space, 63, 359-364, 2011.

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Bagiya, M. S., K. N. Iyer, H. P. Joshi, S. V. Thampi, T. Tsugawa, S. Ravindran, R. Sridharan, and B. M.
Pathan, Low-latitude ionospheric-thermospheric response to storm time electrodynamical coupling
between high and low latitudes, J. Geophys. Res., 116, A01303, doi:10.1029/2010JA015845.
Magnetic Data Acquisition System (MAGDAS) (Related 1.7)
Yamazaki, Y.; Richmond, A. D.; Yumoto, K, Stratospheric warmings and the geomagnetic lunar tide: 19582007, J. Geophys. Res., 117, A04301, doi:10.1029/2012JA017514, 2012.
Yamazaki, Y.; Yumoto, K.; McNamara, D.; Hirooka, T.; Uozumi, T.; Kitamura, K.; Abe, S.; Ikeda, A.,
Ionospheric current system during sudden stratospheric warming events, J. Geophys. Res., 117, A03334,
doi:10.1029/2012JA017453, 2012.
Miyoshi, Y., H. Fujiwara, H. Jin, H, Shinagawa, H. Liu, Numerical simulation of the equatorial wind jet in thethermosphere, J. Geophys. Res., 117, A03309, doi:10.1029/2011JA017373, 2012.
Pancheva, D.; Miyoshi, Y.; Mukhtarov, P.; Jin, H.; Shinagawa, H.; Fujiwara, H., Global response of theionosphere to atmospheric tides forced from below: Comparison between COSMIC measurements andsimulations by atmosphere-ionosphere coupled model GAIA, J. Geophys. Res., 117, A07319,
doi:10.1029/2011JA017452, 2012.
H. Liu, M. Yamamoto, S. Tulasi Ram, T. Tsugawa, Y. Otsuka, C. Stolle, E. Doornbos, K. Yumoto, T.
Nagatsuma, Equatorial Electrodynamics and Neutral Background in the Asian Sector During the 2009
Stratospheric Sudden Warming, J. Geophys. Res., 116, A08308, doi:10.1029/2011JA016607, 2011.
H. Liu, E. Doornbos, M. Yamamoto, S. T. Ram, Strong thermosphere cooling during the 2009 major
statratosphere warming, Geophys. Res. Lett., 38, L12102, doi:10.1029/2011GL047898, 2011.
Yamazaki, Y.; Yumoto, K.; Uozumi, T.; Cardinal, M. G., Intensity variations of the equivalent Sq current
system along the 210° magnetic meridian, J. Geophys. Res., 116, A10308, doi:10.1029/2011JA016632,
2011.
H. Liu, M. Yamamoto, Weakening of the mid-latitude summer night anomaly during geomagnetic storms,
Earth. Planets and Space, 63, 371-375, 2011.
Miyoshi, Y., H. Fujiwara, H. Jin, H, Shinagawa, H. Liu , K. Terada, Model study on the formation of theequatorial mass density anomaly in the thermosphere, J. Geophys. Res., 116, A05322,
doi:10.1029/2010JA016315, 2011.
Jin, H.; Miyoshi, Y.; Fujiwara, H.; Shinagawa, H.; Terada, K.; Terada, N.; Ishii, M.; Otsuka, Y.; Saito, A.,
Vertical connection from the tropospheric activities to the ionospheric longitudinal structure simulated bya new Earth's whole atmosphere-ionosphere coupled model, J. Geophys. Res., 116, A01316,
doi:10.1029/2010JA015925, 2011.
Luhr, H. H. Liu,J. Park, New aspects of the coupling between thermosphere and ionosphere, with special
regards to CHAMP mission results, Aeronomy of the Earth's atmosphere and ionosphere, eds. Abdu, M.
A., Pancheva, D., Springer, 303-316, 2011.
Luhr, H. J. Park, P. Ritter, H. Liu, In-situ CHAMP observations of the ionosphere-thermosphere coupling,
Space Sci. Rev., doi:10.1007/s11214-011-9798-4, 2011.

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