SuperDARNレーダーと地上共役点観測による極域電磁圏の南北対称性の研究

1997 Fiscal Year Annual Research Report

• Project/Area Number: 09044106
• Research Category: Grant-in-Aid for international Scientific Research
• Section: Joint Research .
• Research Institution: National Institute of Polar Research
• Principal Investigator: 佐藤 夏雄 国立極地研究所, 情報科学センター, 教授 (50132709)
• Co-Investigator(Kenkyū-buntansha): 宮岡 宏 国立極地研究所, 情報科学センター, 助教授 (10150046) ; 麻生 武彦 国立極地研究所, 北極圏環境研究センター, 教授 (10026255) ; 江尻 全機 国立極地研究所, 資料主幹, 教授 (30013692) ; 巻田 和男 拓殖大学, 工学部, 教授 (40129945) ; 小川 忠彦 名古屋大学, 太陽地球環境研究所, 教授 (60271607)
• Keywords: 共役点 / オーロラ / レーダー / 衛星 / 磁気圏 / プラズマ現象 / 南極 / 北極域

Research Abstract

南極や北極での総合的地上観測やSuperDARNレーダーを用いて、極域の電磁環境変動を明らかにする事を目的にしている。本年度の国際学術による研究実績の概要は以下のとうりである。
1.アイスランドにおけるオーロラ現象の南北共役点観測
南極の昭和基地との可視オーロラの同時観測可能な8-9月と3月に、アイスランドにおいてオーロラ観測を実施した。残念ながら本年の天気が特に悪く、例年より観測回数が少なかった。また、LF〜MF帯の自然電磁波観測を初めて実施した。
2.グリーンランドでの昼間のオーロラ観測
12-1月に、グリーンランドにて可視オーロラの微細構造観測を実施した。興味深い形状と時間変化をするオーロラが高分解能で観測でき、オーロラ粒子の加速機構に新たな手掛かりが得られた。
3.HFレーダー観測
昭和基地のHFレーダーは国際HFレーダ一網観測(SuperDARN)の一環として活動している。本年度の2月には、このSuperDARNレーダーを中心とし、EISCATレーダー、GeotailやAkebono衛星との同時観測を企画し、磁気圏プラズマの時間的・空間的変動について貴重な観測情報を得る事ができた。
4.スカンジナビアでのオーロラとEISCATレーダー観測
キルナにてオーロラの立体観測を、衛星軌道やレーダー視野に合わせて実施した。また、トロムソとスバールバルでのEISCATレーダーの特別観測を国際共同で実施した。

Research Products

• [Publications] Sato, N., Nagaoka, T., Hashimoto, K.and Saemundsson, T..: "Conjugacy of isolated auroral arcs and nonconjugate auroral breakups." J.Geophy.Res.(in press).
• [Publications] Sato, N., Morooka, R., Minatoya, K.and Saemundsson, T.,: "Activities and forms of pulsating auroras at the conjugate-pair observatories nere L=6." Proc.NIPR Symp.Upper Atmos.Phys.11. 134-138 (1998)
• [Publications] Watanabe, M., Pinnock, M., Roger, A., S., Sato, N., Yamagishi, H., Yukimatu, A., S., Greenwald, R., A., Villain, J-P.and Hairston.M., R.: "Localized activation of the destant tail neutral line just prior to substorm onsets." J.Geophy.Res.(in press).
• [Publications] Yang.H., Liu, R.and Sato, N.: "A note on pixel intensity correction in projection transform of an all-sky image." Proc.NIPR Symp.Upper Atmos.Phys.11. 55-60 (1998)
• [Publications] Hashimoto, K.and Sato, N.: "Solar and particle contributions to conjugacy of eastward and westward auroral electrojet intensity." Proc.NIPR Symp.Upper Atmos.Phys.12(in press).
• [Publications] Nose, M., Iyemori, T., Sugiura, M., Slavin, J.A., Hoffman, R., A., Winningham.J.D.and Sato, N.: "Electoron precipitation accompanying Pc 5 pulsations observed by the DE satellites and at a ground station" J.Geopy.Res.(in press).
• [Publications] Watanabe, M., Pinnock, M., Roger, A., S., Sato, N., Yamagishi, H., Yukimatsu, A., S., Greenwald.R., A., Villain, J.P.and Hairston.M.: "Fast equatorward separatrix motion in the nightside ionosphere just prior ot substorms(extended abstract)." Proc.NIPR Symp.Upper Atmos.Phys.12(in press).
• [Publications] Nishitani, N., Ogawa, T., Sato, N., Yamagishi, H., Yukimatu, A., S.and Watanabe, M.: "Averaged Pattern of Ionospheric Echo Region and Convection:Initial Results from the Syowa Station HF Radar." Proc.NIPR Symp.Upper Atmos.Phys.12. 42-49 (1997)
• [Publications] Ogawa, T.: "A Review of Radar and Satellite Observations of Atmospheric Gravity Waves at Syowa Station" Proceedings of the International Symposium on Environmental Research in the Antarctic. (in press).
• [Publications] Ogawa, T., Nishitani, N., Pinnock, M., Sato, N., Yamagishi, H.and Yukimatu, A.S.: "Polar Cap Patches and Auroral Blobs Observed with Antarctic HF Radar:Preliminary Results." Proc.NIPR Symp.Upper Atmos.Phys.11. 11-18 (1997)
• [Publications] Saka, O., Watanabe, O., Shinohara, M., Sato, N., Yamagishi, H., Kadokura, A.and Reeves, G.D.: "A modulation of Pc 3 amplitude and associated precipitation." Proc.NIPR Symp.Upper Atmos.Phys.10. 160-164 (1997)
• [Publications] Saka, O., Okafa.K., Watanabe, O., Beker, D.N., Reeves, G.D.and Belian, R.D.: "Pi2-associated particle flux and magnetic field modulations in geosynchronous altitudes." J.Geophys.Res.102. 11363-11373 (1997)
• [Publications] Saka, O., Shimoizumi, M. and Sato, N.: "Earth induction effect for Pc 5 pulsations observed by unmanned magnetometer network near Syowa Station,Antarctica." J.Geomag/Geoelectr.49. 1197-1204 (1997)
• [Publications] Shinohara, M., Yoshikawa, A., Saka, O., Solovyev, S.I., Vcrshinin, E.F., Trivedi, N.B., Da Costa.J.M.: "Wave characteristics of daytime and nighttime Pi2 pulsations at the equatorial and low latitudes." Geophy.Res.Lett.24. 2279-2284 (1997)
• [Publications] Saka, O., Akaki, H., Watanabe, O.Shinohara, M.and Baker, D.N.: "An initial response of magnetic fields at geosynchronous orbit to Pi 2 onset as observed from the dip-equator." Ann.Geophysicae. (in press).
• [Publications] Murayama, Y., Mori, H., Kainuma, S., Ishii, M., Nishimuta, I: "Development of high-resolution imaging riometer for the middle and upper atmosphere observation program at Poker Flat,Alaska" J.Atmos.Terr.Phys.925-937 (1997)
• [Publications] Nishino, M., Yamagishi, H., Stauning, P., Rosenberg, T.J.and Holtet, J.A.: "Location,spatial scale and motion of radio wave absorption in the cusp-latitude ionosphere observed by imaging riometer" J.Atmos.Solar-Terr.Phys.59,4. 903-924 (1997)
• [Publications] Ayukawa, M., Makita, K., Nishino, M.and Yamagishi, H.: "Comparison between prenoon and postnoon auroras during quiet disturbed conditions" Proc.NIPR Sympo.Upper Atmos.Phys.10. 142-146 (1997)
• [Publications] Nishino, M., Nozawa, S.and Holtet, J.A.: "Daytime ionospheric absorptions in the polar cap associated with poleward drifting F-region plasma patches" Earth,Planets and Space. (in press).
• [Publications] Tsutsumi, M., Ejiri, M., Okano, S., Sato, N., Yamagishi, H., Igarashi, K.and Tsuda, T.: "MF radar observations of Antarctic mesosphere and lowerthermosphere" Proc.NIPR Symp.Upper Atmos.Phys.10. 109-116 (1997)
• [Publications] Kawahara, T.D., Okano, S., Abe, T., Fukunishi, H.and Ito, K.: "Glass-type hydrogen and deuterium absorption cells developed for D/H ratio measurements in the Martian atmophere" Appl.Opt.36,No.10. 2229-2237 (1997)
• [Publications] Okada, M., Ejiri, M., Okano, S., Taguchi, M.and Takeshita, S.: "System design and initial results of all sky imager at South Pole" Nankyoku Shiryo(Antarctic Record). 41,No.3. 613-630 (1997)
• [Publications] Ranta, H.and Yamagishi, H.: "Small-scale structure of electron density in the D region onset phases of auroral absorption substorm" Adv.Space Res.19,No.1. 159-168 (1997)
• [Publications] Yamagishi, H., Fujita, Y., Sato, N., Stauning, P., Nishino, M.and Makita, K.: "Conjugate features of auroras observed by TV cameras and imaging riometers at auroral zone and polar cap conjugate-pair stations" Polar Cap Boundary Phenomena,ed.by A.Egeland,Netherlands,Kluwer A.P.(in press).
• [Publications] Fujita, Y., Yamagishi, H., and Sato, N.: "Seasonal variation in the latitude of geomagnetically conjugate points observed with imaging riometers in the auroral zone" Nankyoku Shiryo(Antarctic Record). Vol.42,No.1. 1-20 (1998)
• [Publications] Ekanayake, E.M.P., Aso, T.and Miyahara, S.: "Background wind effect on propagation of nonmigrating diurnal tides in the middle atmosphere" J.Atmos.Solar-Terr.Phys.59(4). 401-429 (1997)
• [Publications] 浦島 智、藤田 淳文、麻生 武彦: "オーロラトモグラフィにおける再構成アルゴリズムの検討" 国立極地研究所南極資料. 41(2). (1997)
• [Publications] Steen, Aa., Braendstroem, U., Gustavsson, B.and Aso, T.: "ALIS-A Multi-station imaging system at high latitude with multi-disciplinary" Proc.13th ESA Symposium on European Rocket and Balloon Programs and related Research,Oeland,Sweden,26-29 May,1997,ESA SP. 397. 261-266 (1997)
• [Publications] Aso, T., Urashima, A., Ejiri, M., Miyaoka, H., Steen, Aa., Braendstroem, U.and Gustavsson, B: "First results of auroral tomography from ALIS-Japan multi-station observations in March,1995,Earth" Planets and Space. 50(1). 63-80 (1998)
• [Publications] Aso, T., Ejiri, M., Urashima, A., Miyaoka, H., Steen, Aa., Braendstroem, U.and Gustavsson.B.: "Auroral tomography analysis of a folded arc observed at the ALIS-Japan multi-station campaign on March 26,1995" Proc.NIPR Symp.Upper Atmos.Phys.11. 1-10 (1998)
• [Publications] EbiharaY., Miyaoka, H., Tohyama, F.and Ejiri, M.: "Loss effects for energetic protons associated with a megnetic storm in the inner magnetosphere" Proc.NIPR Symp.Upper Atmos.Phys.10. 16-28 (1997)