| DC 欄位 |
值 |
語言 |
| DC.contributor | 太空科學研究所 | zh_TW |
| DC.creator | 馮志龍 | zh_TW |
| DC.creator | C-L Fern | en_US |
| dc.date.accessioned | 2001-6-29T07:39:07Z | |
| dc.date.available | 2001-6-29T07:39:07Z | |
| dc.date.issued | 2001 | |
| dc.identifier.uri | http://ir.lib.ncu.edu.tw:88/thesis/view_etd.asp?URN= 85247003 | |
| dc.contributor.department | 太空科學研究所 | zh_TW |
| DC.description | 國立中央大學 | zh_TW |
| DC.description | National Central University | en_US |
| dc.description.abstract | 經由一系列赤道區電離E層純雙流體電漿波發展的模擬分析結果，我們可驗證一些已知理論與現象，例如﹔純雙流體電漿波初始發展符合線性頻散關係; 共振耦合現象的展現; 回波功率隨天頂角變化滿足0.3(dB/度)的分佈以及二維電漿波的非線性發展導致垂直結構產生形變而構成垂直模態分量，最後造成主要電漿波偏離電噴流漂移(E×B )方向發展。然而，更重要的是這些垂直模態的發展具有非對稱結構。由我們的模擬結果發現電漿波尺度大小會影響非對稱的發展，即大尺度模態(波長尺度大於3m)朝k‧E＜0 方向傳播發展，而小尺度模態(包括3m電漿波)則朝 k‧E＞0 的方向傳播發展，其中3m電漿波符合VHF雷達非對稱觀測結果。我們認為非對稱結構發展主要導因於赤道電噴流的強大垂直背景極化電場E 。同時，由於強大固定的垂直背景極化電場E 影響，我們發現雙流體電漿波頻率僅與該水平模態Kx有關，以至於電漿波傾斜傳播(Kz≠0 )的相速低於線性理論之預測值，尤其在大尺度電漿波最明顯。 | zh_TW |
| dc.description.abstract | From the series of simulation results for two-stream waves in the equatorial E-region ionosphere, we have studied the dispersion relations, the resonant coupling, and the echo power variation with the zenith angle rate of approximately 0.3(dB/degree). We have also studied the vertical small-scale waves developed from the distortions of the dominant waves. The vertical waves will cause dominant waves to turn away from the electrojet drift direction (E×B ). The important point about the development of vertical modes is asymmetry. We find that the spectral asymmetry depends on the scale size of plasma waves, that is, the large-scale waves (above 3 meters) propagate in the k‧E＜0 region, and the small-scale (smaller than 3 meters) propagate in the k‧E＞0 region. The simulation result of up-down asymmetry for 3-meter wave is consistent with the radar observations. We believe that the background polarization electric field E driving the electrojet is responsible for the spectral asymmetries. In the same time, owning to the strong and fixed background polarization electric field E , the wave frequency depends only on horizontal wave number Kx . Therefore, the phase velocities of many obliquely propagating two-stream waves (Kz≠0 ) are below the value predicted by linear theory, and this characteristic is prominent especially for large-scale waves. | en_US |
| DC.subject | 電離E層 | zh_TW |
| DC.subject | 雙流體電漿波 | zh_TW |
| DC.subject | 非對稱頻譜 | zh_TW |
| DC.subject | 耦合共振 | zh_TW |
| DC.subject | 赤道電噴流 | zh_TW |
| DC.subject | E-region | en_US |
| DC.subject | Two-stream waves | en_US |
| DC.subject | Spectral asymmetries | en_US |
| DC.subject | Resonant coupling | en_US |
| DC.subject | Equatorial electrojet | en_US |
| DC.title | 赤道區電離E 層純雙流體電漿波之模擬研究 | zh_TW |
| dc.language.iso | zh-TW | zh-TW |
| DC.title | Simulations of Pure Two-Stream Waves in the Equatorial E-region Ionosphere | en_US |
| DC.type | 博碩士論文 | zh_TW |
| DC.type | thesis | en_US |
| DC.publisher | National Central University | en_US |