| Summary: | 碩士 === 國立中央大學 === 太空科學研究所 === 96 === With the globally coveraged observations of electron density profile retrieved from FORMOSAT-3/COSMIC radio occultation measurements, we are able to avoid the limitation of past measurements. In the previous investigations, most measurements of ionosphere focus on bottom side ionosphere, therefore the information on properties of topside ionosphere are not well-documented, including scale height, vertical diffusion velocity, total electron content(TEC), and so on. This dissertation compares ionospheric parameters, such as NmF2, hmF2, topside scale height and topside TEC, between IRI model and COSMIC data globally. Their seasonal variation and daily variation are also studied. We find that there is significant difference between COSMIC measurement and IRI model for nighttime low latitude, especially in the topside ionosphere. With 18 months COSMIC data from 200609 to 200802, we also observe the seasonal variation of peak electron density and its relation to the solar activity. The result shows a positive correlation between them.
|
|---|
