Simultaneous equatorial plasma bubble observation using amplitude scintillations from GNSS and LEO satellites in low-latitude region

Earth, Planets and Space

Full Paper

Susumu Saito¹  Kornyanat Hozumi²  Michi Nishioka²  Mamoru Yamamoto³  Pornchai Supnithi⁴  Lin Min Min Myint⁴  Khanitin Seechai⁴ 

[1] Electronic Navigation Research Institute, National Institute of Maritime, Port and Aviation Technology, 182-0012, Tokyo, Japan;National Institute of Information and Communications Technology, 184-8795, Koganei, Tokyo, Japan;Research Institute for Sustainable Humanosphere, Kyoto University, 611-011, Uji, Kyoto, Japan;School of Engineering, King Mongkut’s Institute of Technology Ladkrabang, 10520, Bangkok, Thailand;

关键词: Space weather;    Global Navigation Satellite System;    Low earth orbit satellites;    TEC;    Ionospheric irregularity;    Equatorial plasma bubble;    Amplitude scintillation index;   

DOI  :  10.1186/s40623-023-01877-6

 received in 2023-05-13, accepted in 2023-07-30,  发布年份 2023

来源: Springer

【 摘 要 】

This study estimates the scale sizes of the plasma density irregularities and the longitudinal width associated with equatorial plasma bubbles (EPBs) in equatorial and low-latitude regions. By analyzing amplitude scintillation S4 indices and total electron content (TEC) measured from low earth orbit (LEO) satellite’s beacon signals with 400 MHz and Global Navigation Satellite System (GNSS) L1/E1 signals with 1575.42 MHz, recorded by receivers at the KMITL station in Bangkok, Thailand (geographic; 13.73° N, 100.77°E, magnetic: 7.26°N), we investigate the characteristics of these irregularities. We collected data of 154 LEO satellite pass events during nighttime on 21 disturbed days in four equinoctial months in 2021. Based on the presence or absence of the scintillation effects on GNSS and LEO beacon signals, the events are categorized into four classes to estimate the scale size of the plasma density irregularities. The analysis suggests that events with both GNSS and LEO scintillations, as well as events with GNSS scintillation alone, occur predominantly before midnight assuming the presence of the small-scale size of the irregularities within EPB. However, events with only LEO scintillation occur throughout the whole night and some events are observed before the events with both GNSS and LEO scintillations. Post-sunset LEO scintillation alone may be attributed to the onset of EPBs developing at low altitude, while post-midnight LEO scintillation events near the magnetic equator, observed during periods of low GNSS Rate of TEC Index (ROTI) values, are associated with bottom-side ionospheric irregularities but are not linked with EPB. The findings are consistent with previous researches on the generation and decay of electron density irregularities within plasma bubbles. However, this study provides new insights by using specific data sets and analysis techniques, offering a more comprehensive understanding of the association of LEO scintillations with bottom-side ionospheric irregularities near the magnetic equator, not observed in the ROTI map.Graphical Abstract

【 授权许可】

CC BY   
© The Society of Geomagnetism and Earth, Planetary and Space Sciences / The Seismological Society of Japan / The Volcanological Society of Japan / The Geodetic Society of Japan / The Japanese Society for Planetary Sciences 2023

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