A Simulation Study of Ionization Depletion in the Auroral Ionospheric F-Region Caused by Strong Convection Electric Field  

作　　者：Cai Hong-tao Ma Shu-ying G. Kirchengast 

机构地区：[1] College of Electronic Information, Wuhan University, Wuhan 430072, China

出　　处：《Wuhan University Journal of Natural Sciences》2001年第3期680-686,共7页武汉大学学报（自然科学英文版）

基　　金：the National Natural Science Foundation of China (496742 41;40 0 740 3 9) and the Research Fund forthe Doctoral Program of Higher Education in China

摘　　要：THe effects of strong convection electric field on the electron density in the auroral ionosphericF-region have been simulated numerically by means of a physical model. It is found that an enhancement of electric field directed west-northward in post-noon or west-southward in pre-noon results in an ionization depletion with its maximum at altitudes 40–50 km higher than that of theF 2 peak. When the enhanced electric field lasts for 45 min and has a maximum about 32 mV/m, the resulted ionization depletions reach their maximum at the time just ～10 min behind the time when the convection electric field and ion temperature enhancements reach their maximum. This is consistent well with EISCAT observations. The magnitudes of the percentage ionization depletions and their recovery time are dependent not only on the intensity of the electric field, but also on the diurnal variation phase of the background electron density.THe effects of strong convection electric field on the electron density in the auroral ionosphericF-region have been simulated numerically by means of a physical model. It is found that an enhancement of electric field directed west-northward in post-noon or west-southward in pre-noon results in an ionization depletion with its maximum at altitudes 40–50 km higher than that of theF 2 peak. When the enhanced electric field lasts for 45 min and has a maximum about 32 mV/m, the resulted ionization depletions reach their maximum at the time just ～10 min behind the time when the convection electric field and ion temperature enhancements reach their maximum. This is consistent well with EISCAT observations. The magnitudes of the percentage ionization depletions and their recovery time are dependent not only on the intensity of the electric field, but also on the diurnal variation phase of the background electron density.

关 键 词：auroral ionosphere ionospheric model numerical simulation convection electric field ionization depletion 

分 类 号：P353.2[天文地球—空间物理学] P352.4[天文地球—地球物理学]