TY - JOUR
T1 - Propagation Mechanism of Medium Wave Broadcasting Waves Observed by the Arase Satellite
T2 - Hectometric Line Spectra
AU - Hashimoto, Kozo
AU - Shinbori, Atsuki
AU - Otsuka, Yuichi
AU - Tsuchiya, Fuminori
AU - Kumamoto, Atsushi
AU - Kasahara, Yoshiya
AU - Matsuoka, Ayako
AU - Nagano, Isamu
AU - Miyoshi, Yoshizumi
AU - Yokoyama, Tatsuhiro
N1 - Funding Information:
We thank Mamoru Yamamoto of Kyoto University for his useful comments. We thank all members of the ERG project and the ERG Science Center. This research was partially supported by a Grant‐in‐Aid for Scientific Research from the Japan Society for the Promotion of Science (21H01146).
Publisher Copyright:
© 2021. American Geophysical Union. All Rights Reserved.
PY - 2021/11
Y1 - 2021/11
N2 - A new type of terrestrial line spectra found by the Arase satellite was reported in 2018. These spectra are called “hectometric line spectra (HLS)”. They primarily consist of constant frequency narrowband components at frequencies between 525 kHz and 1,700 kHz, which originate and are sometimes amplified from AM broadcasting waves. In addition to these, other generated emissions are observed. Entrances and the mode conversion of the AM broadcasting waves into the equatorial and low-latitude ionosphere with plasma density depletion called plasma bubbles are observed. Electron density profiles and equatorial plasma bubbles are examined through Global Positioning System (GPS)-Total electron content (TEC) analyses. As a result, the Arase satellite which observed the HLS passed through the TEC depression region near the equatorial ionosphere associated with plasma bubbles. The scenario based on the mode conversion of the L-O mode to the Z mode and vice versa was confirmed with observations and GPS-TEC analyses. Another entrance when foF2 estimated from TEC is lower than 1,000 kHz instead of a plasma bubble is also found. No mode conversion is necessary, then.
AB - A new type of terrestrial line spectra found by the Arase satellite was reported in 2018. These spectra are called “hectometric line spectra (HLS)”. They primarily consist of constant frequency narrowband components at frequencies between 525 kHz and 1,700 kHz, which originate and are sometimes amplified from AM broadcasting waves. In addition to these, other generated emissions are observed. Entrances and the mode conversion of the AM broadcasting waves into the equatorial and low-latitude ionosphere with plasma density depletion called plasma bubbles are observed. Electron density profiles and equatorial plasma bubbles are examined through Global Positioning System (GPS)-Total electron content (TEC) analyses. As a result, the Arase satellite which observed the HLS passed through the TEC depression region near the equatorial ionosphere associated with plasma bubbles. The scenario based on the mode conversion of the L-O mode to the Z mode and vice versa was confirmed with observations and GPS-TEC analyses. Another entrance when foF2 estimated from TEC is lower than 1,000 kHz instead of a plasma bubble is also found. No mode conversion is necessary, then.
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U2 - 10.1029/2021JA029813
DO - 10.1029/2021JA029813
M3 - Article
AN - SCOPUS:85119673387
SN - 2169-9380
VL - 126
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
IS - 11
M1 - e2021JA029813
ER -