极区电离层F区加热激发极低频波研究

"极区电急流天线"辐射依赖于低电离层D/E区背景电急流,而高电离层F区极低频调制加热,可产生抗磁性电流,形成极低频波辐射源。利用电离层F区一维时变加热数值模型,采用全波解算法研究高纬Troms(69.59°N,19.23°E)地区电离层F区极低频调制加热。模拟结果表明,极区高电离层激发的极低频波与极区低电离层激发的结果不同。加热泵波的有效辐射功率(effective radiated power,ERP)、调制频率及电离层背景对极低频波强度有着重要影响。

GENERATION OF EXTREMELY LOW FREQUENCY WAVES BY MODULATED HEATING OF POLAR IONOSPHERIC F REGION

Polar ionospheric heaters operated by HARRP and EISCAT have generated extremely low frequency waves by modulating the auroral electrojet at D and E region altitudes. However, the auroral electrojet often varies over time and is not always present. Alternatively, modulated F-region HF heating can generate ionospheric diamagnetic current, and the periodic modulation results in a magnetic moment that radiates extremely low frequency waves. Based on a one-dimensional time physical model of polar ionospheric heating and a full-wave model, we analyzed the features of extremely low frequency waves over Tromsø (69.59°N, 19.23°E). The results showed that extremely low frequency waves on the ground are different from lower ionospheric modulation, i.e., radiation of polar electrojet antenna. Furthermore, effective radiated power (ERP), modulated frequency, and ionospheric background, have significant influence on the generated extremely low frequency wave.