Numerical study of the auroral particle transport in the polar upper atmosphere

• Published in: Science in China Series E: Technological Sciences
• Main Authors: Cai HongTao, Ma ShuYing, Pu ZuYin
• Other Authors: Ma, SY (reprint author), Wuhan Univ, Sch Elect Informat, Wuhan 430079, Peoples R China., Wuhan Univ, Sch Elect Informat, Wuhan 430079, Peoples R China., Minist Educ PRC, Key Lab Geospace Environm & Geodesy, Wuhan 430079, Peoples R China., Peking Univ, Sch Earth & Space Sci, Beijing 100871, Peoples R China.
• Format: Journal/Newspaper
• Language: English
• Published: 中国科学e辑 技术科学 2008
• Subjects: aurora; particle precipitation; polar upper atmosphere; electron transport equation; numerical simulation; CHARACTERISTIC ELECTRON-ENERGY; HYDROGEN ATOM AURORA; THEORETIC MODEL; MONTE-CARLO; DEPOSITION; DEGRADATION; FLUXES; FUV; IONOSPHERE; IONIZATION; EISCAT
• Online Access: https://hdl.handle.net/20.500.11897/248647; https://doi.org/10.1007/s11431-008-0216-4

Starting from the Boltzmann equation and with some reasonable assumptions, a one-dimensional transport equation of charged energetic particles is derived by taking account of major interactions with neutral species in the upper atmosphere, including the processes of elastic scattering, the excitation, the ionization and the secondary electron production. The transport equation is numerically solved, for a simplified atmosphere consisting only of nitrogen molecules (N(2)), to obtain the variations of incident electron fluxes as a function of altitude, energy and pitch angle. The model results can describe fairly the transport characteristics of precipitating auroral electron spectra in the polar upper atmosphere; meanwhile the N(2) ionization rates calculated from the modeled differential flux spectra also exhibit good agreements with existing empirical models in terms of several key parameters. Taking the energy flux spectra of precipitating electrons observed by FAST satellite flying over EISCAT site on May 15, 1997 as model inputs, the model-calculated ionization rate profile of neutral atmosphere consists reasonably with that reconstructed from electron density measurements by the radar. Engineering, Multidisciplinary Materials Science, Multidisciplinary SCI(E) EI 1 ARTICLE 10,SI 1759-1771 51