Advances in Ionospheric Space Weather by Using FORMOSAT-7/COSMIC-2 GNSS Radio Occultations

Jann-Yenq Liu; Chien-Hung Lin; Panthalingal Krishnanunni Rajesh; Chi-Yen Lin; Fu-Yuan Chang; I-Te Lee; Tzu-Wei Fang; Dominic Fuller-Rowell; Shih-Ping Chen

doi:10.3390/atmos13060858

Atmosphere (May 2022)

Advances in Ionospheric Space Weather by Using FORMOSAT-7/COSMIC-2 GNSS Radio Occultations

Jann-Yenq Liu,
Chien-Hung Lin,
Panthalingal Krishnanunni Rajesh,
Chi-Yen Lin,
Fu-Yuan Chang,
I-Te Lee,
Tzu-Wei Fang,
Dominic Fuller-Rowell,
Shih-Ping Chen

Affiliations

Jann-Yenq Liu: Center for Astronautical Physics and Engineering, National Central University, Taoyuan City 320317, Taiwan
Chien-Hung Lin: Department of Earth Sciences, National Cheng Kung University, Tainan City 70101, Taiwan
Panthalingal Krishnanunni Rajesh: Department of Earth Sciences, National Cheng Kung University, Tainan City 70101, Taiwan
Chi-Yen Lin: Center for Astronautical Physics and Engineering, National Central University, Taoyuan City 320317, Taiwan
Fu-Yuan Chang: Center for Astronautical Physics and Engineering, National Central University, Taoyuan City 320317, Taiwan
I-Te Lee: Space Weather Operation Office, Central Weather Bureau, Taipei City 100006, Taiwan
Tzu-Wei Fang: NOAA Space Weather Prediction Center, Boulder, CO 80305, USA
Dominic Fuller-Rowell: NOAA Space Weather Prediction Center, Boulder, CO 80305, USA
Shih-Ping Chen: Department of Earth Sciences, National Cheng Kung University, Tainan City 70101, Taiwan

DOI: https://doi.org/10.3390/atmos13060858
Journal volume & issue: Vol. 13, no. 6
p. 858

Abstract

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This paper provides an overview of the contributions of the space-based global navigation satellite system (GNSS) radio occultation (RO) measurements from the FORMOSAT-7/COSMIC2 (F7/C2) mission in advancing our understanding of ionospheric plasma physics in the purview of space weather. The global positioning system (GPS) occultation experiment (GOX) onboard FORMOSAT-3/COSMIC (F3/C), with more than four and half million ionospheric RO soundings during April 2006–May 2020, offered a unique three-dimensional (3D) perspective to examine the global electron density distribution and unravel the underlying physical processes. The current F7/C2 carries TGRS (Tri-GNSS radio occultation system) has tracked more than 4000 RO profiles within ±35° latitudes per day since 25 June 2019. Taking advantage of the larger number of low-latitude soundings, the F7/C2 TGRS observations were used here to examine the 3D electron density structures and electrodynamics of the equatorial ionization anomaly, plasma depletion bays, and four-peaked patterns, as well as the S4 index of GNSS signal scintillations in the equatorial and low-latitude ionosphere, which have been previously investigated by using F3/C measurements. The results demonstrated that the denser low-latitude soundings enable the construction of monthly global electron density maps as well the altitude-latitude profiles with higher spatial and temporal resolution windows, and revealed longitudinal and seasonal characteristics in greater detail. The enhanced F7/C2 RO observations were further applied by the Central Weather Bureau/Space Weather Operation Office (CWB/SWOO) in Taiwan and the National Oceanic and Atmospheric Administration/Space Weather Prediction Center (NOAA/SWPC) in the United States to specify the ionospheric conditions for issuing alerts and warnings for positioning, navigation, and communication customers. A brief description of the two models is also provided.

Published in Atmosphere

ISSN: 2073-4433 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Physics: Meteorology. Climatology
Website: http://www.mdpi.com/journal/atmosphere/

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