摘要: | 在本研究中,我們擬發展一套理論數值模式,模擬電離層E域與F域的電子密度以及多種離子(亦即O+(2P), O+(2D), N2+, O+(4S), N+, O2+, 與NO+等七種離子)密度隨時間與高度的變化。在本模式中,電子與離子密度的產生與消失,將透過光化游離作用、光電子撞擊游離效應、離子與中性大氣的化學反應、以及中性氣體的分解游離等作用所支配。在模擬過程中,將選用三種不同的太陽輻射模型,亦即 Solar Dynamics Observatory-Extreme Ultraviolet Variability Experiment (SDO-EVE),EUV flux model for Aeronomic Calculations (EUVAC),以及Hinteregger-Fukui-Gilson (HFG)太陽輻射模型,作為數值模式的輸入驅動源,透過前述各種作用與效應產生各自的自由電子與離子。另外根據AE-C衛星的現地測量,比較上述三種太陽輻射模型所得到的電子與離子密度剖面與衛星觀測的差異,以比較三種太陽輻射模式的優異性。此外,在本研究中並將本研究所發展的模式所模擬出的電子與離子密度剖面與國際電離層模型(International Reference Ionosphere, IRI)的結果作比較,了解是否可透過理論分析與模擬,獲得比IRI經驗模型更準確的電漿密度模型。 ;In this study, we try to develop a time-dependent theoretical numerical model to simulate the density profiles of the ions (i.e., O+(2P), O+(2D), N2+, O+(4S), N+, O2+, and NO+) and free electrons in E and F regions. In this model, the ion photoionization production rates, the photoelectron ionization production effect, the chemical reactions between the ionized species and the neutral compositions, dissociative ionization effect are considered, and the plasma transport processes are not included. Three different solar radiation models (i.e., Solar Dynamics Observatory-Extreme Ultraviolet Variability Experiment (SDO-EVE), EUV flux model for Aeronomic Calculations (EUVAC), and Hinteregger-Fukui-Gilson (HFG) solar irradiance model) are employed to generate the electron and ions through the photoionization production effect. On the basis of the in-situ measurements made by AE-C satellite, the simulated electron and ion density profiles obtained from the above-mentioned three solar radiation models as the inputs of the developed theoretical model will be compared with the satellite measurements to see which solar radiation model is superior to others. In addition, the modeled results will also compare with the IRI results to realize whether the model developed in this research is better than the IRI model. |