江簡富臺灣大學:電信工程學研究所麥肇倫Mai, Chao-LunChao-LunMai2010-07-012018-07-052010-07-012018-07-052009U0001-1806200922212900http://ntur.lib.ntu.edu.tw//handle/246246/188269A tsunami propagating on an open sea can induce an internal gravity wave (IGW) into thetmosphere. The IGW will be amplified due to the decrease of mass density with height,nd will cause a transient vibration in the ionosphere starting at about 150 km above theea level. Global positioning system (GPS) and ground-based HF Doppler radar have beeneported to detect such ionospheric variation.n this work, we propose a complete model which incorporates the loss mechanisms dueo thermal conduction, viscosity, and ion drag. A dispersion relation is derived which revealshat only a specific range of spatial spectrum can propagate through the atmosphere tohe ionosphere, and IGW amplitude will reach a maximum at certain altitude. Throughon-neutral collision, chemical loss, and photoionization, electron irregularity is induced inhe passage of the gravity wave. The waveform, amplification factor, propagation speed andravel time can be applied up to more than 800 km high.he ionospheric electron density irregularity induced by the Sumatra tunami on December6, 2004 was detected by satellite-born altimeter and global positioning system (GPS)round the Indian Ocean. The model is applied to the 2004 Sumatra tsunami profile which isestored from the satellite recorded data. The tsunami wave triggers an intenal gravity waven the atmosphere, which propagates upward with an average velocity of about 700 - 800/s into the ionosphere and significantly disturbs the electron density by 3 to 4 TECU. TheGW is then trapped at about 400 km height, and moves horizontally with the same speed ashat of the tsunami. Approximately 11 minutes after the tsunami triggers the atmosphericisturbances, ionospheric irregularity starts to be detected by the satellites that pass over,nd peak perturbation of TEC will be observed in about an hour. The simulation resultsell explain the TEC observation in magnitude, waveform, and time delay.Abstract iiable of Contents ivist of Figures viiiist of Tables ixcknowledgment xi Introduction 1 Modeling of Electron Density Perturbation in the Ionosphere by Tsunamiinducedravity Wave 10.1 Brief Review of Tsunami Models . . . . . . . . . . . . . . . . . . . . . . . . 10.2 Tsunami-Atmosphere Coupling . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 Propagation Model of Gravity Wave . . . . . . . . . . . . . . . . . . . . . . . 12.4 Chemical Reactions in F Region . . . . . . . . . . . . . . . . . . . . . . . . . 17ii.5 Interaction between Gravity Waves and Ion Motion . . . . . . . . . . . . . . 20.6 Effect of Gravity Wave on Photoionization Rates . . . . . . . . . . . . . . . 22.7 Effect of Gravity Wave on Chemical Loss Rates . . . . . . . . . . . . . . . . 25.8 Electron Density Perturbation . . . . . . . . . . . . . . . . . . . . . . . . . . 26.9 Model Validation and Discussions . . . . . . . . . . . . . . . . . . . . . . . . 28 Simulation of Ionospheric Electron Density Irregularities Induced by 2004umatra Tsunami 41.1 Electron Density Perturbation Caused by IGW . . . . . . . . . . . . . . . . 41.2 Reconstruction of 2004 Sumatra Tsunami Profile . . . . . . . . . . . . . . . 46.3 Results and Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Conclusion 61 Bibliography 631047329 bytesapplication/pdfen-US海嘯重力波電離層全球衛星定位系統tsunamigravity waveionosphereGPSthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/188269/1/ntu-98-R95942019-1.pdf