• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 12
  • Tagged with
  • 12
  • 12
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The South Atlantic radiation anomaly

Van Rooyen, H O January 1964 (has links)
Part I. (1) An elementary treatment of the motion of charged particles in a magnetic field is presented. The concept of guiding centre motion is introduced, and is used in outlining the theory of particle drifts. (2 ) The motion of charged particles in the geomagnetic field is discussed, and the concept of adiabatic invariance introduced. (3) Mc Iliwains coordinates for mapping the distribution of charged particles trapped in the geometric field are defined and briefly discussed. (4) A survey of present knowledge of the Van Allen radiation zones is made. Particular attention is given to the distribution, characteristics, and variability of the trapped radiation. (5) The Cape Town magnetic anomaly, the Brazil radiation anomaly and the South Atlantic radiation anomaly are discussed. The electrons entering the South Atlantic radiation anomaly are shown to be those monitored over Iowa by the US satellite Injun I. Part 11. (1) It is shown how the geomagnetic field can, at high altitudes and over relatively short distances, be approximated by the field of a monopole. A new method is developed which enables one to plot the energy absorbed from an electron (which moves in a monopole field in the atmosphere) against altitude, given the initial energy and pitch angle of the electron. Some numerical computations using this method are described, and the results discussed. These results are used, in conjunction with US satellite Injun I for the Iowa region, to estimate the energy inout to the atmosphere in the South Atlantic radiation anomaly. The main approximations and simplifying assumptions made in this treatment, are discussed. (2) Geophysical effects generally recognized to be connected with the precipitation of charged particles are discussed. In the course of this discussion the two main theories of the connection between the radiation zones and the auroras are examined. (3) A preliminary discussion, based on the work summarized in point (1) of detectable geophysical events associated with the precipitation of electrons into the South Atlantic radiation anomaly is given. It is concluded that auroral emission, X-ray bursts, and ionospheric ionization in the E region should be more frequent and pronounced in the South Atlantic radiation anomaly than in any other region of comparable invariant latitudes and that the effects of atmospheric heating by precipitated electrons should be detectable over the anomaly. (4) An assessment is made of the value of the method referred to in point (1). Suggestions for its modification and extension are put forward. It is suggested that if more extensive rocket and satellite data on the low energy component of the electron flux become available, this method can be employed in a rigorous theoretical investigation of the South Atlantic radiation anomaly. Summary, p. 98-100.
12

Characteristics of the mesoscale field-aligned currents in the dusk sector of the auroral oval based on data from the Swarm satellites / Swarm衛星データに基づくオーロラオーバル夕方側領域におけるメソスケール沿磁力線電流の特性

Yokoyama, Yoshihiro 25 January 2021 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22875号 / 理博第4641号 / 新制||理||1667(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 田口 聡, 教授 松岡 彩子, 教授 橋口 浩之 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Page generated in 0.1131 seconds