| Summary: | 碩士 === 國立成功大學 === 太空天文與電漿科學研究所 === 98 === The Tiny Ionospheric Photometer (TIP) on FORMOSAT-3/COSMIC measures the radiance due to the emission at 135.6 nm with high spatial resolution of the horizontal structure of the ionosphere. During nighttime, this radiance varies with the electron density in the ionosphere below the satellite. In this research, we use both the nighttime data of TIP measurements, Auroral Electrojet index (AE index) from 2006 August to 2009 August, and apply the probability theory to define a coefficient statistically. The coefficient represents the relationships between the radiance measured by TIP and AE index.
The major purpose of this thesis is to apply the coefficient to determine the auroral oval boundaries during different intensities of geomagnetic disturbances. Furthermore, we investigate the relations of radiance and AE index inside the auroral oval. The results show that the auroral oval boundaries shift equatorward when geomagnetic disturbances increase, and the average widths of the auroral oval remain constant around magnetic latitudes. The auroral oval boundaries and widths vary with different magnetic local time. In addition, during precipitation of energetic particles down to the auroral oval, the auroral electrojet currents are enhanced, AE index are also affected by these currents. As AE increases, this can extend to higher and lower magnetic latitudes and the scenario is consistent with the results of this research.
|
|---|
