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Research on thegeneration mechanisms of ion upflow in the polar cap ionosphere by using ESR.

Research Project

Project/Area Number 11440144
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Space and upper atmospheric physics
Research InstitutionNagoya University

Principal Investigator

FUJII Ryoichi  Nagoya University, Solar-Terrestiral Environment Laboratory, Professor, 太陽地球環境研究所, 教授 (00132712)

Co-Investigator(Kenkyū-buntansha) WATANABE Shigeto  Hokkaido University, Graduate School of Science, Professor, 大学院・理学研究科, 教授 (90271577)
OGAWA Tadahiko  Nagoya University, Solar-Terrestiral Environment Laboratory, Professor, 太陽地球環境研究所, 教授 (60271607)
NOZAWA Satonori  Nagoya University, Solar-Terrestiral Environment Laboratory, Associate Professor, 太陽地球環境研究所, 助教授 (60212130)
SHIOKAWA Kazuo  Nagoya University, Solar-Terrestiral Environment Laboratory, Associate Professor, 太陽地球環境研究所, 助教授 (80226092)
MAEDA Sawako  Kyoto Women's University, Faculty for the Study of Contemporary Society, Professor, 現代社会学部, 教授 (00199613)
BUCHERT S. C (BUCHERT S・C)  名古屋大学, 太陽地球環境研究所, 助教授 (70293719)
Project Period (FY) 1999 – 2001
Project Status Completed (Fiscal Year 2001)
Budget Amount *help
¥14,600,000 (Direct Cost: ¥14,600,000)
Fiscal Year 2001: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥4,600,000 (Direct Cost: ¥4,600,000)
Fiscal Year 1999: ¥6,400,000 (Direct Cost: ¥6,400,000)
Keywordsion outflow / ion heating / polar cap region / auroral zone / high latitude ionosphere / Svalbard EISCAT radar / EISCAT radar / IS spectra
Research Abstract

By using EISCAT radars together with satellites, we have investigated mainly three aspects of ion upflow phenomena in order to understand the generation mechanisms of ion up flow. The first step was to investigate the relationship between ion upflow and particle precipitation which is different between several magnetospheric regions. The second step was to investigate the relationship between ion upflow and heating, from the macroscopic point of view. The third step was to investigate the characteristics of naturally enhanced ion-acoustic lines (NEIALs), which may be caused by plasma instabilities and are strongly related to ion upflow from the microscopic point of view. We have examined the regions where dayside field-aligned (FA) ion upflows occur, based on a statistical analysis using approximately 170 simultaneous events between the ESR and the DMSP satellites. This systematic analysis for ion upflow has never been examined. We found that ion up flows occur not only in the cusp and … More cleft (the low altitude portion of the low-latitude boundary layer (LLBL)) which have been considered as ion up flow regions, but also in the topside ionosphere connected to the mantle region. Ion upflows seldom occur either in the Boundary Plasma Sheet (EPS) or in the Central Plasma Sheet (CPS) in the dayside high latitudes. Almost all of the events in which the average FA ion velocity is more than 100 m s^<-1> are associated with sufficient soft electron precipitation (differential energy flux of electrons at 100 eV > 10^7 eV cm^<-2> s^<-1> sr^<-1> eV^<-1>). Although soft electron precipitation also sufficiently exists in the EPS, the ion velocities are mostly less than 100 m s^<-1>. The present results indicate that soft particle precipitation is the predominant energy source driving ion up flow in the topside ionosphere, but it works on ion upflow effectively in the higher latitude regions in the dayside and not in the EPS. In addition, plasma heating associated with FA ion upflow in the daysjde topside ionosphere has been examined using data obtained simultaneously with the ESR and the EISCAT VHP radar, and also the wave number (k)-dependence of the received power in high signal-to-noise ratio (SNR) conditions, occurring for NEIALs and for real satellites, has been investigated.
The results from these three investigations lead to the conclusion that the energy of soft electron precipitation is considered as the main source of the ion up flow. The energy of soft particle precipitation is supplied to the ions in the topside ionosphere via wave-particle interaction, such as wave-induced transverse ion heating, and upward parallel electric field due to anomalous resistively produced by plasma turbulence. Thus generation mechanisms of ion upflow must have the transversely ion heating and the upward acceleration by wave-particle interaction while the induced plasma waves decay. In addition to direct precipitation effects, namely enhanced ambipolar diffusion and heat flux, wave-particle interaction may hence play an important role in driving ion upflow. Less

Report

(4 results)
  • 2001 Annual Research Report   Final Research Report Summary
  • 2000 Annual Research Report
  • 1999 Annual Research Report
  • Research Products

    (33 results)

All Other

All Publications (33 results)

  • [Publications] Fujii, Ryoichi: "Field-aligned ion motions in the E and F regions"Journal Geophysical Rescearch. (in press). (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Sugino, Masahiko: "Relative importance of the electric field and the ionospheric conductivity to the polar ionospheric currents"Journal Geophysical Rescearch. (in press). (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Saito, Susumu: "Observation of isotropic electron temperature in the turbulent E region"Annales Geophysicae. 19. 11-15 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Oyama, Shin-ichiro: "Generation of atmospheric gravity waves associated with auroral activity in the polar F-region"Journal Geophysical Rescearch. 106. 18,543-18,554 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Nagatsuma, Tutomu: "Higher latitude Pi3 pulsations observed by the EISCAT VHF radar"Advanges Space Research. 27(8). 1429-1431 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Balan, N.: "Changes in the ionosphere over EISCAT during ion frictional heating events"Advanges Space Research. 27(8). 1413-1416 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Fujii, R., et al.: "Field-aligned ion motions in the E and F regions"J. Geophys. Res. (in press). (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Sugino, M., et al.: "Relative importance of the electrid field and the ionospheric conductivity to the polar ionospheric currents"J. Geophy. Res.. (in press). (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Saito, S., et al.: "Observation of isotropic electron temperature in the turbulent E region"Ann. Geophys.. 19. 11-15 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Oyama, S., et al.: "Generation of atmospheric gravity waves as asociated with auroral activity in the polar F-region"J. Geophys. Res.. 106. 18,543-18,554 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Nagatsuma, T., et al.: "Higher latitude Pi3 pulsations observed by the EISCAT VHP radar"Adv. Space Res.. 27(8). 1429-1431 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Balan, N., et al.: "Changes in the ionosphere over EISCAT during ion frictional heating events"Adv. Space Res.. 27(8). 1413-1416 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Fujii, Ryoichi: "Field-aligned ion motions in the E and F regions"Journal Geophysical Rescearch. (in press). (2002)

    • Related Report
      2001 Annual Research Report
  • [Publications] Sugino, Masahiko: "Relative importance of the electric field and the ionospheric conductivity to the polar ionospheric currents"Journal Geophysical Rescearch. (in press). (2002)

    • Related Report
      2001 Annual Research Report
  • [Publications] Saito, Susumu: "Observation of isotropic electron temperature in the turbulent E region"Annales Geophysicae. 19. 11-15 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] Oyama, Shin-ichiro: "Generation of atmospheric gravity waves associated with auroral activity in the polar F-region"Journal Geophysical Rescearch. 106. 18,543-18,554 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] Nagatsuma, Tutomu: "Higher latitude Pi3 pulsations observed by the EISCAT VHF radar"Advanges Space Research. 27(8). 1,429-1,431 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] Balan, N.: "Changes in the ionosphere over EISCAT during ion frictional heating events"Advanges Space Research. 27(8). 1,413-1,416 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] Fujii,Ryoichi: "Energy coupling between the magnetosphere ionosphere and thermosphere"Advanges Space Research. 25(1). 213-218 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Ogawa,Yasunobu: "Simultaneous EISCAT Svalbard and VHF radar observations of ion upflows at different aspect angles"Geophysical Rescearch Letters. 27. 81-84 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Endo,Minoru: "Ion outflow and in flow at the topside ionosphere observed by the EISCAT VHF radar"Annales Geophysicae. 18. 170-181 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Yoshida,Naofumi: "Coordinated Akebono and EISCAT observations of suprathermal ion outflows in the nightside inverted-V region"Journal of Atmospheric Solar-Terrestrial Physics. 62. 449-465 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Saito,Susumu: "Effects of kappa distribution electrons on incoherent scaner spectra."Annales Geophysicae. 18. 1216-1223 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Oyama,Shinichiro: "Effects of atmospheric oscillations on the field-aligned ion motions in the polar F-region"Annales Geophysicae. 18. 1154-1163 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Ogawa,Yasunobu: "Frequency dependent power fluctuations : a feature of the ESR system or physical?"Annales Geophysicae. 18. 1224-1230 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Ogawa,Tadahiko: "Plasma density supression process around the cusp revealed by simultaneous CUTLASS and EISCAT Svalbard radar observations"Journal Geophysical Research. (In press). (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Saito,Susumu: "Observation of isotropic electron temperature in the turbulent E region"Annales Geophysicae. 19. 11-15 (2001)

    • Related Report
      2000 Annual Research Report
  • [Publications] Fujii, Ryoichi: "Statistical characteristics on electromagnetic energy transfer between the magnetosphere, the ionosphere, and the thermosphere"Journal of Geophysical Research. 104. 2357-2365 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] Fujii, Ryoichi: "Energy coupling between the magnetosphere, ionosphere and thermosphere"Advanges Space Research. 25(1). 213-218 (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] Buchert, S.C.: "Naturally enhanced ion-acoustic lines seen with the ESR"Advanges Space Research. 23. 1699-1704 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] Ogawa, Yasunobu: "Simultaneous EISCAT Svalbard and VHF radar observations of ion upflows at different aspect angles"Geophysical Research Letters. 27. 81-84 (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] Endo, Minoru: "Ion outflow and inflow at the topside ionosphere observed by the EISCAT VHF radar"Annales Geophysicae. 18. 170-181 (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] Nozawa, Satonori: "A case study of the auroral E region neutral wind on a quiet summer day; Comparison of three methods of the EISCAT UHF radar for deriving the E region wind"Radio Science. (in press). (2000)

    • Related Report
      1999 Annual Research Report

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Published: 1999-04-01   Modified: 2016-04-21  

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