Effects of the stratospheric sudden warming on the temperature in the MLT region
Yasunobu Miyoshi 1

Characteristics of polar mesosphere summer echoes observed with oblique incidence HF radars at Syowa Station
Tadahiko Ogawa, Keisuke Hosokawa, Nozomu Nishitani,
                               Natsuo Sato,Hisao Yamagishi and Akira Sessai Yukimatu 13

Lightning discharges in association with mesospheric optical phenomena in Japan and their effect on the lower ionosphere
Yasuhide Hobara, Masashi Hayakawa, Kenji Ohta
                               and Hiroshi Fukunishi 30

Control factor of solar cycle variation of auroral kilometric radiation
Atsushi Kumamoto, Takayuki Ono, Masahide Iizima
                               and Hiroshi Oya .48

SC-related kilometric and hectometric radiations observed by the Akebono satellite in the polar regions
Atsuki Shinbori, Takayuki Ono, Masahide Iizima,
                               Atsushi Kumamoto and Hiroshi Oya 60

The mechanism of energy release and field-aligned current generation during substorms and solar ares
Igor M.Podgorny, Alexander I.Podgorny, Shigeyuki Minami and
               Rizwan Rana 77

Solar flare and CME predictions using numerical MHD simulations
Alexander I.Podgorny, Igor M.Podgorny and Shigeyuki Minami 84

Anomalous sporadic-E layers observed before M 7.2 Hyogo-ken Nanbu earthquake;Terrestrial gas emanation model
Tadanori Ondoh 96

VLF signatures of ionospheric perturbations associated with winter lightning in the Hokuriku area of Japan
Takuya Otsuyama, Tadao Kariya and Masashi Hayakawa 109

Experiments on meteor burst communications in the Antarctic
Akira Fukuda, Kaiji Mukumoto, Yasuaki Yoshihiro,
      Masauji Nagasawa, HisaoYamagishi, Natsuo Sato, Huigen Yang,
                       Ming Wu Yao and Li Jun Jin 120

Research Note

A comparison between vertical winds in the lower thermosphere and magnetic field perturbations on the ground
Mamoru Ishii, Mark Conde, Roger W.Smith, Matthew Krynicki,
                   Eiichi Sagawa and Shin ’ichi Watari 137

Second harmonics of auroral kilometric radiation observed by the Akebono satellite
Akira Hosotani,Takayuki Ono, Masahide Iizima and
                             Atsushi Kumamoto 146

Report

20th century operation of the Tromso Ionosonde
C.M.Hall and T.L.Hansen 155

An overview of the terdiurnal tide observed by polar radars and optics
Takehiko Aso 167

Note to contributors 177
Author index 179