COMMISSION G : Ionospheric Radio and Propagation (Nov. '98 - Oct. '01)
Edited by Koichiro Oyama
G1. Ionospheric Techniques
Igi et al. [1999] studied thermospheric meridional winds for one solar cycle (1981-1991) that were derived from hmF2 data at Kokubunji, Japan and pointed out the solar cycle variations of the winds over Japan to be qualitatively similar to those in other sectors.
Shiokawa et al. [1999] reported development of comprehensive optical instruments (OMTIs: optical mesosphere thermosphere imagers) which consists of an imaging Fabry-Perot interferometer, three all-sky cooled-CCD cameras, three tilting photometers and a Spectral Airglow Temperature Imager (SATI). The OMTIs measure nighttime airglow at altitudes of 80-400 km.
An integrated optical/radio observations of Arctic middle and upper atmosphere at Poker Flat, Alaska, has been conducted by a Japan-US collaboration. Middle atmosphere and thermospheric studies and scientific results arose from MF radar, Rayleigh lidar, Fabry Perot interferometers, all-sky imagers, etc. at Poker Flat, Alaska, and Super DARN HF radar at King Salmon, and related-funded works.
G2. Ionospheric Structure and Modeling
G2.1. Ionospheric Structure
Ionosphere structure was mainly studied from electron density observation. Electron tenperture data obtained in 1981-1982 by Japans sun observer Hinotori are still being analysed to study seasonal latitude , and longitude dependence with respect to local time .[Denton et al,1999]
[Dabas er al,1999],[Bailey et al 2000]. Electron Tenperature of the topside ionosphere which is useful to calculate topside electron density was studied up to the height of 8000km using Akebono data[Pavlov,2000a,2000b],[Pavlov,2001].
Mu radar is actively being operated and many findings have been reported[Su et al,1999],[Zhang et al,1999],[Balan et al,1999],[Kawamura et al,2000],[Zhang et al,2000],[Zhang et al,2001a,2001b],[Kawamura et al,2002],[Zhang et al,2002].
G2.2. Ionospheric Disturbances
Since the middle of 1996,University of Electro-Communication has made a routine observation of TEC using GPS in Chofu, Tokyo. We examine in this paper the relationship between the perturbation components of TEC and geomagnetic field variations during 11 storm events for 1997-1998 to clarify the mid-latitude characteristics of TEC variations at the time of magnetic storms(Yamamoto et al.,2000). The perturbation components of TEC were derived every 20 seconds by subtracting quiet-time TEC values which are estimated as the average of both 3 days just before and after the storm period. The magnetic field data from Memanbetsu Magnetic Observatory, Hokkaido, are used for the identification of the storm-time variations. Our results show that (1) the amplitude level of the TEC variation tends to increase during the first 24 hr of storm and then decrease below its usual-day level with recovery in one or two days later for the typical magnetic storm, and (2) during a negative-value phase of the TEC variation, which
follows the initial positive hump structure, the perturbation amplitude of TEC shows a remarkable reduction in summer compared to in winter.
Shiokawa et al. [2000] studied storm-time airglow enhancements observed at midlatitudes using an airglow imager, a GPS receiver network, ionosondes and the DMSP satellite. The airglow enhancement observed equatorward of Japan was explained by equatorial plasma fountain caused by electric field penetration associated with storm-time substorms, which was identified as an upward plasma drift by the DMSP satellite.
Kubota et al. [2000] and Saito et al. [2001] showed large-scale view of medium-scale traveling ionospheric disturbances (MSTIDs) over Japan using multi-point airglow imaging observations and a GPS receiver network. They found that MSTIDs propagated southwestward over more than 1500 km. The correlation between MSTIDs seen in the airglow and GPS-TEC (total electron content) was very good. Occurrence of field-aligned irregularities observed by the MU radar was also correlated with the observed MSTIDs.
Sahai et al. [2001] studied small-scale (30-50km) airglow depletion structures in 630-nm images during a storm of February 12, 2000, possibly caused by non-linear interactions of mesoscale TIDs and enhanced equatorial anomaly. They also showed that enhanced storm-time ionospheric disturbances represented by spread-F and GPS phase fluctuations were confined in the midlatitudes.
Minami et al. [1999] performed an experiment of artificial stimulation of the ionosphere using high power radio waves at the HIPAS facility in Alaska. Diagnostics, using a multi-channel 30 MHz scanning cosmic radio noise absorption, at a site 35 km from the transmission site revealed the excited height of 90 km. Atmospheric pressure waves with a period of 10 min, probably generated in the ionosphere by the high-power HF, were simultaneously observed on the ground.
G2.3. Ionospheric Irregularities
Kagan et al. [2000] tried to explain the generation mechanism of midlatitude E region irregularities in sporadic E layer in terms of neutral wind-driven instability instead of traditional plasma instabilities pertinent to the E region.
Ionospheric E and F region irregularities at southern high latitudes has been explored using the SuperADRN coherent HF radars at Syowa Station. Fukumoto et al. [1999, 2000] analyzed a large data-set of F region echoes to find relationship among echo power, Doppler velocity and spectral width, and discussed plasma instability processes capable of explaining the relationship. Ogawa et al. [2001] examined statistical characteristics of E region Doppler velocity to show in particular that part of the velocities at near ranges represents motions of the lower thermosphere and the upper mesosphere. Makarevitch et al. [2001] compared simultaneous HF and VHF radar echoes returned from common volume in the E region to show dissimilarity between echo characteristics at HF and VHF bands, and pointed out the importance of HF wave refraction due to disturbed ionosphere.[Tsunoda Many results are being ohfained by MO radar and other radar [Tsunoda et al,1999],[Tsunoda et al,2000],[Rao et al,2000],[Maruyama et al,2000],[Otsuka et al,2002],[Saitoh et al,2002],[Maruyamaet al,2002].
G2.4. Ionospheric Dynamics
Shiokawa et al. [2001] reported unusual appearance of an SAR arc at 34.7 MLAT (northern part of Japan) during a weak storm of Dst = -49nT, about 2 days after the very weak solar wind interval of May 10-11, 1999.
G2.5. Particles and Auroras
From observations with a 500-MHz incoherent scatter radar on Svalbard, Buchert et al. [1999] found unusual coherent echoes probably due to ion-acoustic plasma waves excited by field-aligned currents.
Nishino et al. [1999a] case-studied slowly varying daytime radio wave absorption at 30 MHz observed with an imaging riometer at Ny Alesund, Svalbard. From simultaneous F region HF backscatter echo and electron flux observations, they concluded that the absorption was likely caused by precipitation of eastward drifting auroral electrons generated by substorms in the midnight region.
30 MHz imaging riometers at Ny Alesund (NYA) and Danmarkshavn (DMH) in the Arctic and Zhongshan (ZHS) in Antarctica were used to examine conjugate features of daytime ionospheric radio wave absorption. Nishino et al. [1999b] studied post-noon absorption simultaneously observed at these stations. The absorption was a spike-type with weak intensity during high solar wind dynamic pressure and was due to high-energy electrons precipitation from the closed dayside magnetosphere. Nishino et al. [2000] identified simultaneous afternoon and noon absorption spikes at NYA and ZHS and at DMH and ZHS, respectively, in association with a steep increase in solar wind dynamic pressure and its synchronized spike-type IMF excursion. Magnetic field compression associated with the sudden pressure increase might stimulate a population of magnetospheric electrons located at the equatorward boundary of the cusp/cleft. Nishino et al. [2001] reported quasi-periodic, conjugate absorption spikes associated with a sequence of solar wind dynamic pressure pulses during northward interplanetary magnetic field. Comparison between absorption images and simultaneous all-sky aurora images at ZHS showed that the spikes had a feature of small-scale, eastward-moving enhancement embedded within a large-scale absorption region
G2.6. Polar Electrodynamics
The SuperDARN HF radars have been utilized to investigate electrodynamics in the cusp ionosphere. Nishitani et al. [1999] found very large-scale (5 hours in magnetic local time) flow burst that occurred in association with large-scale reconnection at the dayside magnetopause under high solar wind density and strong southward interplanetary magnetic field. In conjunction with the EISCAT Svalbard radar, Ogawa et al. [2001] case-studied in detail plasma density suppression process in the cusp ionosphere to find enhanced plasma convection or flow burst to be important process to generate polar patches.
G2.7. Modeling of Planetary Ionospheres
Shinagawa and Bougher [1999] studied the dynamics and structure of the Martian ionosphere using a two-dimensional MHD model. It was found that the scale height of the modeled ionosphere is significnatly smaller than that of the observed ionosphere under typical solar wind conditions, suggesting that the ionosphere of Mars is controlled by possible intsinsic magnetic field or some other effects.
Shinagawa [2000] reviewed observations and modeling studies of the ionosphere of Mars. Recently the Mars Global Surveyor has detected strong but local magnetic field of crustal origin in various regions at Mars, while the global intirinsic magnetic field of core origin was insignificant.
Although the ionosphere of Mars is basically similar to Venus, the crustal magnetic field at Mars is likely to play an important role in the ionospheric processes.
G3. Ionospheric Radio Propagation
G3.1. ELF/VLF
An analytical time domain solution of ELF electromagnetic waves in the subionospheric waveguide is studied [Nickolaenko et al., 1999d]. Multiple electromagnetic pulses [Nickolaenko and Hayakawa, 1999 a] are found to turn into a single pulse when propagating in the subionospheric waveguide[Nickolaenko and Hayakawa, 1999 b]. A new ELF observing station is established in Moshiri, Hokkaido, using fully-calibrated wide-band(1Hz < f < 1kHz) 3-component ELF measurement to study ELF transients and Schumann resonances [Hobara et al., 2000].
The continuons analog records of the horizontal magnetic field during the period of August 1967 to November 1970 have been analyzed and a comparison of these Schumann resonance data with those made recently in Europe allows us to demonstrate the similarity and stability of the global thunderstorm variations on a seasonal scale [Nickolaenko et al., 1999 e]. We suggest an algorithm for choosing the position for the observation of Schumann resonances [Nickolaenko and Hayakawa, 1999 c]
Detailed analysis of early/fast Trimpi phenomena revealed two different regimes in their temporal behavior. These regimes are used to deduce the plasma structure of the ionospheric perturbation associated with sprites [Molchanov et al., 1998]. The effect of those Trimpi-induced ionospheric perturbations on subionospheric VLF propagation has been studied by means of FDTD method [Otsuyama et al., 2001].
G3.2. VHF
Nishino et al. [1999c] conducted experiments, using radio links between a 30 MHz transmitter located at Murmansk, Russia and two receivers used as an imaging riometer at Ny Alesund, Svalbard, and Tjornes, Iceland, to characterize radio wave scatter in the high-latitude ionosphere, and found that the scatter was caused by large-scale, irregular electron density enhancements at the lower edge of the ionosphere.
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Shinagawa, H. [2000], Our current understanding of the ionosphere of Mars, Adv.Space Res., 26, 1699-1608.
Shinagawa, H., and S. Bougher [1999],A two-dimensional MHD model of the solar wind
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Shiokawa, K., Y. Katoh, M. Satoh, M. K. Ejiri, T. Ogawa, T. Nakamura, T. Tsuda and R. H. Wiens [1999], "Development of optical mesosphere thermosphere imagers (OMTI)," Earth Planets Space, vol.51, pp.887-896.
Shiokawa, K., Y. Otsuka, T. Ogawa, K. Igarashi, S. Miyazaki, F. J. Rich, A. Saito and K. Yumoto [2000], "Comprehensive imaging observations of mid-latitude ionospheric disturbances during storm time substorms," J. Geophys. Res., vol.105, pp.27067-27080.
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Tsunoda, R. T., J. J. Buonocore, A. Saito, T. Kishimoto, M. Yamamoto, and S. Fukao, [1999],First Observations of Quasi-Periodic Radar Echoes From Stanford, California, Geophys. Res. Lett., 26, 995-998.
Tsunoda, R. T., M. Yamamoto, H. Mori, and S. Fukao [2000], SEEK S310-25: Quasi-Periodic Echoes and Polarization Electric Fields, Geophys. Res. Lett., 27(20), 3281-3284.
Yamamoto, A., Y. Ohta, T. Okuzawa, S. Taguchi, I. Tomizawa and T. Shibata [2000],"Characteristics of TEC variations observed at Chofu for geomagnetic storms," Earth Planets Space, vol.52, no.11, pp.1073-1076.
Yamazaki, R., K. Igarashi, M. Nagayama, and I. Nishimuta [2000], "The effect of signal saturation on wind velocity estimates using MF radar signals," Adv. Space Res.
Zhang, S.-R., S. Fukao, and W. L. Oliver [1999], Data Modeling and Assimilation Studies with the MU Radar, J. Atmos. Solar Terr. Phys., 61, 563-583.
Zhang, S.-R., S. Fukao, W. L. Oliver, and Y. Otsuka [1999], The Height of the Maximum Ionospheric Electron Density over the MU Radar, J. Atmos. Solar Terr. Phys., 61, 1367-1383.
Zhang, S.-R.. W. L. Oliver, S. Fukao, and Y. Otsuka [2000], A Study of the Forenoon Ionospheric F2-Layer Behavior Over the Middle and Upper Atmospheric Radar, J. Geophys. Res., 105(A7), 15823-15833.
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Zhang, S.-R., W. L. Oliver, J. M. Holt, and S. Fukao [2002], Solar EUV Flux, Exospheric Temperature and Thermospheric Wind Inferred from Incoherent Scatter Measurements of Electron Density Profile at Millstone and Shigaraki, Geophys. Res. Lett., In press.
Miscellaneous
Abe, T., D.J. Knudsen, A.W. Yau, and S. Watanabe, E. Sagawa [2001], Simultaneous satellite and radar observations of the polar ion outflow and the flux variation with the geomagnetic condition, Adv. Space Res., 27, 8, 1403-1412.
Balan, N., I.S. Batista, M.A. Abdu, G.J. Bailey, S. Watanabe, J. MacDougall [2000], Variability of an additional layer in the equatorial ionosphere over Fortaleza, J. Geophys. Res., 105, 10603-10613.
Balan, N., R. Fujii. [2001], Changes in the ionosphere over EISCAT during ion frictional heating events, Adv. Space. Sci., 27, 1413-1416.
Buchert, S.C., A.P. van Eyken, T. Ogawa, S. Watanabe [1999], Naturally enhanced ion-acoustic lines seen with the EISCAT Svalbard radar, Adv. Space Res., 23, 1699-1704.
Ejiri, M. K., K. Shiokawa, T. Ogawa, T. Nakamura, R. Maekawa, T. Tsuda, and M. Kubota, [2001],Small-scale gravity waves near the mesopause observed by four all-sky airglow imagers, J. Geophys. Res., 106 (D19), 22793-22799.
Endo, M., R. Fujii, Y. Ogawa, S.C. Buchert, S. Nozawa, S. Watanabe, N. Toshida [2000], Ion outflow and downflow at the topside ionosphere observed by the EISCAT VHF radar, Ann. Geophysicae, 18, 170-181.
Gavrilov, N. M., H. Hashiguchi, and S. Fukao [1999], Multi-Beam MU Radar Measurements of Advective Accelerations in the Atmosphere, Geophys. Res. Lett., 26, 315-318.
Gavrilov, N. M. and S. Fukao [1999], A Comparison of Seasonal Variations of Gravity Wave Intensity Observed by the MU Radar With a Theoretical Model, J. Atmos. Sci., 56, 3485-3494.
Gavrilov, N. M., S. Fukao, and T. Nakamura [1999] Peculiarities of Interannual Changes in the Mean Wind and Gravity Wave Characteristics in the Mesosphere over Shigaraki, Japan, Geophys. Res. Lett., 26, 2457-2460.
Gavrilov, N., and S. Fukao [1999], The MU Radar Measurements and Modeling of the Gravity Wave Climatology and Sources in the Atmosphere, Adv. Space Res., 24, 565-574.
Gavrilov, N. M., S. Fukao, and T. Nakamura [2000], Average Statistical Characteristics of Long Gravity Waves Observed by the Middle and Upper Atmosphere Radar in the Mesosphere, J. Geophys. Res., 105(D7), 9365-9379.
Gavrilov, N. M. S. Fukao, and T. Nakamura [2000], Gravity Wave Intensity and Momentum Fluxes in the Mesosphere over Shigaraki, Japan (35N, 136E) during 1986-1997, Ann. Geophys., 18, 834-843.
Gavrilov N.M., and S. Fukao [2001], Hydrodynamic tropospheric wave sources and their role in gravity wave climatology of the upper atmosphere from the MU radar observations, J. Atmos. Solar-Terr. Phys., 63 (9), 931-943.
Higashikawa, A., T. Nakamura, and T. Tsuda [1999], Seasonal Variations of Gravity Waves Observed with an OH CCD Image at Shigaraki (35N, 136E), Japan, Adv. Space, Res., 24, 561-564.
Hsiao, C.-C., J.-Y. Liu, R. T. Tsunoda, S. Fukao, S. Saroso, K. Nozaki, V. L. Badillo, F. T. Berkey [2001],S.-W. Chen, and M. Yamamoto, Evidence for the geographic control of additional layer formation in the low-latitude ionosphere, Adv. Space Res., 27 (6/7), 1293-1297.
Iwagami, N., T. Shibaki, T. Suzuki, Y. Yamada, H. Ohnishi, Y. Takahashi, H. Yamamoto, H. Sekiguchi, K. Mori, Y. Sano, M. Kubota, Y. Murayama, M. Ishii, K.-I. Oyama, R. Yoshimura, M. Shimoyama, Y. Koizumi, K. Shiokawa, N. Takegawa, and T. Nakamura [2001], The WAVE 2000 campaign, Overview and preliminary results, J. Atmos. solar-Terr. Phys., In print.
Kasahara, Y., T. Hosoda, T. Mukai, S. Watanabe, I. Kimura, H. Kojima, R. Niitsu [2001], ELF/VLF Waves Correlated with Transversely Accelerated Ions in the Auroral Region Observed by Akebono, J. Geophys. Res., 106, 21123-21136.
Kobayashi, K., T. Kitahara, T. D. Kawahara, Y. Saito, A. Nomura, T. Nakamura, T. Tsuda, M. Abo, C. Nagasawa and M. Tsutsumi [1999], Simultaneous measurements of dynamical structure in the mesopause region with lidars and MU radar, Earth Planets and Space, 51, 731-739.
Kubo K., and T. Sugiyama, and S. Fukao [2002], Evaluation of Mesospheric VHF Echoes Observed with the MU Radar, Radio Sci., In press.
Kubota, M., K. Shiokawa, M. K. Ejiri, Y. Otsuka, T. Ogawa, T. Sakanoi, H. Fukunishi, M. Yamamoto, S. Fukao, and A. Saito [2000], Traveling Ionospheric Disturbances Observed in the OI 630-nm Nightglow Images Over Japan by Using a Multi-Point Imager Network during the FRONT Campaign, Geophys. Res. Lett. 27(24), 4037-4040.
Lieberman, R. S., A. K. Smith, S. J. Franke, R. A. Vincent, J. R. Isler, A. H. Manson, C. E. Meek, G. J. Fraser, A. Fahrutdinnova, T. Thayaparan, W. K. Hocking, J. McDougall, T. Nakamura, and T. Tsuda [2000], Comparison of mesospheric and lower thermospheric residual wind with HRDI, MF, and meteor radar winds, J. Geophys. Res., 105, 27023-27035.
Miyagawa, H., T. Nakamura, T. Tsuda, C. Nagasawa, M. Abo, T. D. Kawahara, K. Kobayashi, T. Kitahara and A. Nomura [1999], Observations of mesospheric sporadic sodium layers with the MU radar and sodium lidars, Earth Planets and Space, 51, 785-797.
Murayama, Y., K. Igarashi, I. Nishimuta, K.-I. Oyama, T. Tsuda, T. Nakamura, H.-U. Widdel, K. Schlegel, and S. Fukao [1999], Cooperative Wind Observation in the Upper Mesosphere and Lower Thermosphere with Foil Chaff Technique, the MU Radar, and Yamagawa MF Radar, Earth, Planets and Space, 51, 719-729.
Murayama, Y., K. Igarashi, I. Nishimura, R. Yamazaki, K.-I. Oyama, T. Tsuda, T. Nakamura, S. Fukao, H.-U. Widdel, and K. Schlegel [1999], Wind Observations in the MLT Region over Southeren Japan, by Using Foil Chaff Technique, Yamagawa MF Radar and the MU Radar, Adv. Space Res., 24, 575-578.
Nakamura, T., T. Tsuda, R. Maekawa, M. Tsutsumi, K. Shiokawa, and T. Ogawa [2001],Seasonal variation of gravity waves with various temporal and horizontal scales in the MLT region observed with radar and airglow imaging, Adv. Space Res., 27 (10), 1737-1742.
Nakamura, T., A. Higashikawa, T. Tsuda, and Y. Matsushita [1999], Seasonal variations of gravity wave structures in OH airglow with a CCD imager at Shigaraki, Earth Planets and Space, 51, 897-906.
Nakamura, T., S. Morita, T. Tsuda, H. Fukunishi, and Y. Yamada [2002], Horizontal structure of wind velocity field around the mesopause region derived from meteor radar observations, J. Atmos. Solar-Terr. Phys., In press.
Namboothiri, S. P., T. Tsuda, and T. Nakamura [1999], Interannual Variability of mesospheric mean winds observed with the MU radar, J. Atmos. solar Terr. Phys, 61, 1111-1122.
Namboothiri, S.P., P. Kishore, K. Igarashi, T. Nakamura, and T. Tsuda [2000], MF radar observations of mean winds over Yamagawa (31.2N, 130.6E) and Wakkanai (45.4N, 141.7E), J. Atmos. solar Terr. Phys., 62, 1177-1187.
Nishimura, K., T. Sato, T. Nakamura, and M. Ueda [2001], High sensitivity radar-optical observations of faint meteors, IEICE T. Electron, E84C (12), 1877-1884.
Ogawa, Y., R. Fujii, S.C. Buchert, S. Nozawa, S. Watanabe, A.P. van Eyken [2000], Simultaneous EISCAT Svalbard and VHF radar observations of ion upflows at different aspect angles, Geophys. Res. Lett., 27, 81-84.
Pickett, J.S., D.A. Gurnett, J.D. Menietti, M.J. LeDocq, J.D. Scudder, L.A. Frank, J.B. Sigwarth, K.L. Ackerson, D.D. Morgen, J.R. Franz, P.M. Kintner, B.T. Tsurutani, C.M. Ho, J. Chen, T.A. Fritz, C.T. Russell, W.K. Peterson, Y. Kasahara, I. Kimura, S. Watanabe, G.G. Arkos, G. Rostoker, S. Kokubun, H. Fukunishi, R.F. Pfaff, F.S. Mozer, S.-Y. Hsieh, T. Mukai, M.O. Chandler [1999], Plasma waves observed during cusp energetic particle events and their correlation with Polar and Akebono satellite and ground data, Adv. Space Res., 24, 23-33.
Roettger, J., and S. Fukao [1999],Preface to Mesopause Region Structure, Dynamics and Composition, Adv. Space Res., 24, 535.
R. A. Buriti, T. Nakamura, T. Tsuda, S. Fukao, M. Tsutsumi, H. Takahashi, and P. P. Batista, [2000],Mesopause Temperature Observed by Airglow OH Spectra and Meteor Echoes at Shigaraki (34.9N, 136.1E), Japan, Adv. Space Res., 26 (6), 1005-1008.
Sato, T., T. Nakamura, and K. Nishimura [2000], Orbit determination of meteros using the MU radar, EICE Trans. Commun., E83-B (9), 1990-1995.
Shiokawa, K., Y. Katoh, M. Satoh, M. K. Ejiri, T. Ogawa, T. Nakamura, T. Tsuda, and R. H. Wiens, [1999],Development of optical mesosphere thermosphere imagers (OMTI), Earth Planets and Space, 51, 887-896.
Shiokawa, K., M. K. Ejiri, T. Ogawa, and T. Nakamura [2000], Distant lunar sodium tail observed in the Japanese local-time sector during the Leonid meteor shower of 1998, J. Geophys. Res., 105, 24621-24626.
Shiokawa, K., M. K. Ejiri, Y. Otsuka, T. Ogawa, M. Kubota, K. Igarashi, A. Saito, and T. Nakamura [2000],Multi-point observations of short-period mesospheric gravity waves over Japan during the FRONT Campaign, Geophys. Res. Lett., 27, 4057-4060.
Tsutsumi, M., D. Holdsworth, T. Nakamura, and I. M. Reid [1999],Meteor observations with an MF radar, Earth Planets and Space, 51, 691-699.
Takeda S., T. Nakamura, and T. Tsuda [2001], An improvement of wind velocity estimation from radar Doppler spectra in the upper mesosphere, Ann. Geophys., 19 (8), 837-843.
Takahashi, H., P. P. Batista, R. A. Buriti, D. Gobbi, T. Nakamura, T. Tsuda, and S. Fukao [1999], Response of the airglow OH emission, temperature and mesopause wind to the atmospheric wave propagation over Shigaraki, Japan, Earth Planets and Space, 51, 863-875.
Tsuda, T., T. Nakamura , A. Nomura, T. D. Kawahara, C. Nagasawa, M. Abo, S. Okano, M. Taguchi and M. Ejiri [2000], Coordinated Observations of the Mesopause Region with Radar and Optical Techniques, Adv. Space Res., 26, 907-916.
Yamada, Y., H. Fukunishi, T. Nakamura, and T. Tsuda [2001], Breakdown of small-scale quasi-statinoary gravity wave and transition to turbulence observed in OH airglow, Geophys. Res. Lett., 28 (11), 2153-2156.
Yamada, Y., H. Fukunishi, T. Nakamura, and T. Tsuda [2001], Breaking of small-scale gravity wave and transition to turbulence observed in OH airglow, Geophys. Res. Lett., 28 (11), 2153-2156.
Yoshida, N., S. Watanabe, H. Fukunishi, T. Sakanoi, T. Abe, T. Mukai, H. Hayakawa, A. Matsuoka, Y. Kahahara, R. Fujii, S. Nozawa, Y. Ogawa, M. Syrjasuo [2000], Coordinated Akebono and EISCAT observations of suprathermal ion outflows in the nightside inverted-V region, J. Atmos. Solar-Terr. Phys., 62, 449-465.
Zhou, Q.-H, J. D. Mathews, and T. Nakamura [2001], Implications of meteor observations by the MU radar, Geophys. Res. Lett., 28 (7), 1399-1402.