| Autor: |
Kiyoka Murase, Ryuho Kataoka, Takanori Nishiyama, Koji Nishimura, Taishi Hashimoto, Yoshimasa Tanaka, Akira Kadokura, Yoshihiro Tomikawa, Masaki Tsutsumi, Yasunobu Ogawa, Herbert Akihito Uchida, Kaoru Sato, Satoshi Kasahara, Takefumi Mitani, Shoichiro Yokota, Tomoaki Hori, Kunihiro Keika, Takeshi Takashima, Yoshiya Kasahara, Shoya Matsuda, Masafumi Shoji, Ayako Matsuoka, Iku Shinohara, Yoshizumi Miyoshi, Tatsuhiko Sato, Yusuke Ebihara, Takashi Tanaka |
| Rok vydání: |
2022 |
| Předmět: |
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| Zdroj: |
Journal of Space Weather and Space Climate. 12:18 |
| ISSN: |
2115-7251 |
| DOI: |
10.1051/swsc/2022012 |
| Popis: |
Many studies have been conducted about the impact of energetic charged particles on the atmosphere during geomagnetically active times, while quiet time effects are poorly understood. We identified two energetic electron precipitation (EEP) events during the growth phase of moderate substorms and estimated the mesospheric ionization rate for an EEP event for which the most comprehensive dataset from ground-based and space-born instruments was available. The mesospheric ionization signature reached below 70 km altitude and continued for ~15 min until the substorm onset, as observed by the PANSY radar and imaging riometer at Syowa Station in the Antarctic region. We also used energetic electron flux observed by the Arase and POES 15 satellites as the input for the air-shower simulation code PHITS to quantitatively estimate the mesospheric ionization rate. The calculated ionization level due to the precipitating electrons is consistent with the observed value of cosmic noise absorption. The possible spatial extent of EEP is estimated to be ~8 h MLT in longitude and ~1.5° in latitude from a global magnetohydrodynamic simulation REPPU and the precipitating electron observations by the POES satellite, respectively. Such a significant duration and spatial extent of EEP events suggest a non-negligible contribution of the growth phase EEP to the mesospheric ionization. Combining the cutting-edge observations and simulations, we shed new light on the space weather impact of the EEP events during geomagnetically quiet times, which is important to understand the possible link between the space environment and climate. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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