Simultaneous ground‐ and satellite‐based observation of MF/HF auroral radio emissions
Simultaneous ground‐ and satellite‐based observation of MF/HF auroral radio emissions
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对中频/高频极光无线电发射进行地面和卫星同步观测
DOI：
10.1002/2015ja022101
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Yasunobu Ogawa
中科院分区：
文献类型：
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作者：
Yuka Sato;Atsushi Kumamoto;Yuto Katoh;Atsuki Shinbori;Akira Kadokura;Yasunobu Ogawa
我们报告了首次使用地面和卫星仪器同时测量中高频(MF/HF)极光射电辐射(1 MHz以上)的情况。观测数据是通过冰岛和斯瓦尔巴群岛的地面被动接收器以及安装在Akebono卫星上的等离子体波和探测仪实验(PWS)获得的。我们观测到了两个同时出现的事件，在这两个事件期间，地面探测到的极光咆哮和中频爆发的频率与Akebono卫星通过地面站观测到的地面百米辐射(THR)的频率不同。这种频率差异证实了极光咆哮和Thr是在F峰的不同高度产生的。我们没有同时观察到任何表明极光咆哮和Thr产生相同区域的同步观测。在大多数情况下，中频/高频极光射电发射只由地面探测器或卫星探测器观测到，即使卫星正从地面站上空经过。从太空观察到的探测率高于从地面观察到的探测率。这主要是因为Akebono卫星可以探测到来自更大区域的THR辐射，而且在底部F区域产生的相当大一部分极光射电辐射被与极光电子和太阳紫外线辐射有关的电离区域的电离层吸收和屏蔽所掩盖。
We report on the first simultaneous measurements of medium‐high frequency (MF/HF) auroral radio emissions (above 1 MHz) by ground‐ and satellite‐based instruments. Observational data were obtained by the ground‐based passive receivers in Iceland and Svalbard, and by the Plasma Waves and Sounder experiment (PWS) mounted on the Akebono satellite. We observed two simultaneous appearance events, during which the frequencies of the auroral roar and MF bursts detected at ground level were different from those of the terrestrial hectometric radiation (THR) observed by the Akebono satellite passing over the ground‐based stations. This frequency difference confirms that auroral roar and THR are generated at different altitudes across theFpeak. We did not observe any simultaneous observations that indicated an identical generation region of auroral roar and THR. In most cases, MF/HF auroral radio emissions were observed only by the ground‐based detector, or by the satellite‐based detector, even when the satellite was passing directly over the ground‐based stations. A higher detection rate was observed from space than from ground level. This can primarily be explained in terms of the idea that the Akebono satellite can detect THR emissions coming from a wider region, and because a considerable portion of auroral radio emissions generated in the bottomsideFregion are masked by ionospheric absorption and screening in theD/Eregions associated with ionization which results from auroral electrons and solar UV radiation.