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Advances in Ionospheric Space Weather by Using FORMOSAT-7/COSMIC-2 GNSS Radio Occultations. ATMOSPHERE 2022. [DOI: 10.3390/atmos13060858] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
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.
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Forbes JM, Zhang X, Heelis R, Stoneback R, Englert CR, Harlander JM, Harding BJ, Marr KD, Makela JJ, Immel TJ. Atmosphere-Ionosphere (A-I) Coupling as Viewed by ICON: Day-to-Day Variability Due to Planetary Wave (PW)-Tide Interactions. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2021; 126:e2020JA028927. [PMID: 34650898 PMCID: PMC8507145 DOI: 10.1029/2020ja028927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 05/24/2021] [Indexed: 06/13/2023]
Abstract
Coincident Ionospheric Connections Explorer (ICON) measurements of neutral winds, plasma drifts and total ion densities (:=Ne, electron density) are analyzed during January 1-21, 2020 to reveal the relationship between neutral winds and ionospheric variability on a day-to-day basis. Atmosphere-ionosphere (A-I) connectivity inevitably involves a spectrum of planetary waves (PWs), tides and secondary waves due to wave-wave nonlinear interactions. To provide a definitive attribution of dynamical origins, the current study focuses on a time interval when the longitudinal wave-4 component of the E-region winds is dominated by the eastward-propagating diurnal tide with zonal wavenumber s = -3 (DE3). DE3 is identified in winds and ionospheric parameters through its characteristic dependence on local solar time and longitude as ICON's orbit precesses. Superimposed on this trend are large variations in low-latitude DE3 wave-4 zonal winds (±40 ms-1) and topside F-region equatorial vertical drifts at periods consistent with 2-days and 6-days PWs, and a ~3-day ultra-fast Kelvin wave (UFKW), coexisting during this time interval; the DE3 winds, dynamo electric fields, and drifts are modulated by these waves. Wave-4 variability in Ne is of order 25%-35%, but the origins are more complex, likely additionally reflecting transport by ~20-25 ms-1 wave-4 in-situ winds containing strong signatures of DE3 interactions with ambient diurnal Sun-synchronous winds and ion drag. These results are the first to show a direct link between day-to-day wave-4 variability in contemporaneously measured E-region neutral winds and F-region ionospheric drifts and electron densities.
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Affiliation(s)
- Jeffrey M Forbes
- Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA
| | - Xiaoli Zhang
- Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA
| | - Roderick Heelis
- William B. Hanson Center for Space Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Russell Stoneback
- William B. Hanson Center for Space Sciences, University of Texas at Dallas, Richardson, TX, USA
| | | | | | - Brian J Harding
- Space Sciences Laboratory, University of California Berkeley, Berkeley, CA, USA
| | - Kenneth D Marr
- Space Science Division, U.S. Naval Research Laboratory, Washington, DC, USA
| | - Jonathan J Makela
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Thomas J Immel
- Space Sciences Laboratory, University of California Berkeley, Berkeley, CA, USA
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Kil H, Lee WK, Paxton LJ. Origin and Distribution of Daytime Electron Density Irregularities in the Low-Latitude F Region. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2020; 125:e2020JA028343. [PMID: 32999808 PMCID: PMC7507783 DOI: 10.1029/2020ja028343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/22/2020] [Accepted: 07/31/2020] [Indexed: 06/11/2023]
Abstract
Electron density irregularities on the dayside in the low-latitude F region are understood as remnants (or fossils) of nighttime plasma bubbles. We provide observational evidence of the connection of daytime irregularities to nighttime bubbles and the transport of the daytime irregularities by the vertical motion of the background ionosphere. The distributions of irregularities are derived using the measurements of the ion density by the first Republic of China satellite from March 1999 to June 2004. The seasonal and longitudinal distributions of daytime and nighttime irregularities in low latitudes show a close similarity. The high occurrence rate of daytime irregularities at the longitudes where strong irregularities occur frequently at night provides strong evidence of the association of daytime irregularities with nighttime bubbles. Nighttime irregularities are concentrated in the equatorial region, whereas daytime irregularities spread over broader latitudes. The seasonal and longitudinal variation of the latitudinal spread of daytime irregularities is consistent with the morphologies of plasma density and vertical plasma velocity. The zonal wave number 4 pattern, which corresponds to that in plasma density, is identified in the distribution of daytime irregularities. These observations lead to the conclusion that the morphology of daytime irregularities in the low-latitude F region is dominated by the morphology of bubbles at night and the ionospheric fountain process on the dayside.
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Affiliation(s)
- Hyosub Kil
- The Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
| | | | - Larry J. Paxton
- The Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
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Greer KR, Eastes R, Solomon S, McClintock W, Burns A, Rusch D. Variations of Lower Thermospheric FUV Emissions Based on GOLD Observations and GLOW Modeling. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2020; 125:e2020JA027810. [PMID: 32728510 PMCID: PMC7380304 DOI: 10.1029/2020ja027810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 06/11/2023]
Abstract
Here we compare the global-scale morphology of Earth's the Far-Ultraviolet (FUV) emissions observed by NASA's Global-scale Observations of Limb and Disk (GOLD) mission to those modeled using the Global Airglow (GLOW) code with atmospheric parameters provided by Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM). The O 5S oxygen (135.6 nm) and N2 Lyman-Birge-Hopfield (LBH) emissions are observed over the Western hemisphere every 30 min by the GOLD instrument. The FUV brightness of the thermosphere-ionosphere is expected to vary in systemic ways with respect to geophysical parameters, solar energy input from above, and terrestrial weather input from below. In this paper we examine the O 5S oxygen emission and the N2 LBH emission brightnesses with local time, latitude, season, tides, geomagnetic activity, and solar activity based on GOLD observations and GLOW modeling. Early GOLD observations indicate that the model effectively reproduces the brightness variations with local time and latitude but is biased low in magnitude. However, the TIEGCM is unable to accurately represent the extraordinary nighttime equatorial ionization anomaly observed by GOLD. It is also expected from these results that the signal from geomagnetic storms may obscure tidal signals.
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Affiliation(s)
- K R Greer
- University of Colorado Boulder-LASP Boulder CO USA
| | | | - Stan Solomon
- National Center for Atmospheric Research-HAO Boulder CO USA
| | | | - Alan Burns
- National Center for Atmospheric Research-HAO Boulder CO USA
| | - David Rusch
- University of Colorado Boulder-LASP Boulder CO USA
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A New Empirical Model of NmF2 Based on CHAMP, GRACE, and COSMIC Radio Occultation. REMOTE SENSING 2019. [DOI: 10.3390/rs11111386] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To facilitate F2-layer peak density (NmF2) modeling, a nonlinear polynomial model approach based on global NmF2 observational data from ionospheric radio occultation (IRO) measurements onboard the CHAMP, GRACE, and COSMIC satellites, is presented in this paper. We divided the globe into 63 slices from 80°S to 80°N according to geomagnetic latitude. A Nonlinear Polynomial Peak Density Model (NPPDM) was constructed by a multivariable least squares fitting to NmF2 measurements in each latitude slice and the dependencies of NmF2 on solar activity, geographical longitude, universal time, and day of year were described. The model was designed for quiet and moderate geomagnetic conditions (Ap ≤ 32). Using independent radio occultation data, quantitative analysis was made. The correlation coefficients between NPPDM predictions and IRO data were 0.91 in 2002 and 0.82 in 2005. The results show that NPPDM performs better than IRI2016 and Neustrelitz Peak Density Model (NPDM) under low solar activity, while it undergoes performance degradation under high solar activity. Using data from twelve ionosonde stations, the accuracy of NPPDM was found to be better than that of NPDM and comparable to that of IRI2016. Additionally, NPPDM can well simulate the variations and distributions of NmF2 and describe some ionospheric features, including the equatorial ionization anomaly, the mid-latitude trough, and the wavenumber-four longitudinal structure.
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Abstract
To better understand the ionospheric morphology response to lithospheric activities, we study the global location preference of the positive and negative total electron content (TEC) anomalies persisting continuously for longer than 24 h at middle and low latitudes (within ±60° N geomagnetic latitudes). The TEC is obtained from the global ionospheric map (GIM) of Center for Orbit Determination in Europe (CODE) under the geomagnetic quiet condition of Kp ≤ 3o during the period of 2005 to 2018. There are a few (less than 4%) TEC anomalies that can persist over 24 h. The conjugate phenomenon is most significant in the eastern Asia to Australia longitudinal sector. The result shows the persistence of the positive TEC anomaly along the ring of fire on the western edge of the Pacific Ocean. The high persistence of the TEC anomalies at midlatitudes suggests that thermospheric neutral wind contributes to the anomaly formation.
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Maute A. Thermosphere-Ionosphere-Electrodynamics General Circulation Model for the Ionospheric Connection Explorer: TIEGCM-ICON. SPACE SCIENCE REVIEWS 2017; 212:523-551. [PMID: 30026634 PMCID: PMC6047070 DOI: 10.1007/s11214-017-0330-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/04/2017] [Indexed: 05/24/2023]
Abstract
The NASA Ionospheric Connection explorer (ICON) will study the coupling between the thermosphere and ionosphere at low- and mid-latitudes by measuring the key parameters. The ICON mission will also employ numerical modeling to support the interpretation of the observations, and examine the importance of different vertical coupling mechanisms by conducting numerical experiments. One of these models is the Thermosphere-Ionosphere-Electrodynamics General Circulation Model-ICON (TIEGCM-ICON) which will be driven by tidal perturbations derived from ICON observations using the Hough Mode Extension method (HME) and at high latitude by ion convection and auroral particle precipitation patterns from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE). The TIEGCM-ICON will simulate the thermosphere-ionosphere (TI) system during the period of the ICON mission. In this report the TIEGCM-ICON is introduced, and the focus is on examining the effect of the lower boundary on the TI-system to provide some guidance for interpreting future ICON model results.
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Jin H, Miyoshi Y, Fujiwara H, Shinagawa H, Terada K, Terada N, Ishii M, Otsuka Y, Saito A. Vertical connection from the tropospheric activities to the ionospheric longitudinal structure simulated by a new Earth's whole atmosphere-ionosphere coupled model. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010ja015925] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- H. Jin
- National Institute of Information and Communications Technology; Koganei Japan
| | - Y. Miyoshi
- Department of Earth and Planetary Sciences; Kyushu University; Fukuoka Japan
| | - H. Fujiwara
- Department of Geophysics, Graduate School of Science; Tohoku University; Sendai Japan
| | - H. Shinagawa
- National Institute of Information and Communications Technology; Koganei Japan
| | - K. Terada
- Department of Geophysics, Graduate School of Science; Tohoku University; Sendai Japan
| | - N. Terada
- Department of Geophysics, Graduate School of Science; Tohoku University; Sendai Japan
| | - M. Ishii
- National Institute of Information and Communications Technology; Koganei Japan
| | - Y. Otsuka
- Solar-Terrestrial Environment Laboratory; Nagoya University; Nagoya Japan
| | - A. Saito
- Graduate School of Science; Kyoto University; Kyoto Japan
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Liu L, He M, Yue X, Ning B, Wan W. Ionosphere around equinoxes during low solar activity. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010ja015318] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Libo Liu
- Beijing National Observatory of Space Environment, Institute of Geology and Geophysics; Chinese Academy of Sciences; Beijing China
| | - Maosheng He
- Beijing National Observatory of Space Environment, Institute of Geology and Geophysics; Chinese Academy of Sciences; Beijing China
| | - Xin'an Yue
- Beijing National Observatory of Space Environment, Institute of Geology and Geophysics; Chinese Academy of Sciences; Beijing China
| | - Baiqi Ning
- Beijing National Observatory of Space Environment, Institute of Geology and Geophysics; Chinese Academy of Sciences; Beijing China
| | - Weixing Wan
- Beijing National Observatory of Space Environment, Institute of Geology and Geophysics; Chinese Academy of Sciences; Beijing China
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England SL, Immel TJ, Huba JD, Hagan ME, Maute A, DeMajistre R. Modeling of multiple effects of atmospheric tides on the ionosphere: An examination of possible coupling mechanisms responsible for the longitudinal structure of the equatorial ionosphere. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009ja014894] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- S. L. England
- Space Sciences Laboratory; University of California; Berkeley California USA
| | - T. J. Immel
- Space Sciences Laboratory; University of California; Berkeley California USA
| | - J. D. Huba
- Plasma Physics Division; Naval Research Laboratory; Washington, D. C. USA
| | - M. E. Hagan
- High Altitude Observatory; National Center for Atmospheric Research; Boulder Colorado USA
| | - A. Maute
- High Altitude Observatory; National Center for Atmospheric Research; Boulder Colorado USA
| | - R. DeMajistre
- Johns Hopkins University Applied Physics Laboratory; Laurel Maryland USA
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Liu L, Zhao B, Wan W, Ning B, Zhang ML, He M. Seasonal variations of the ionospheric electron densities retrieved from Constellation Observing System for Meteorology, Ionosphere, and Climate mission radio occultation measurements. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008ja013819] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Libo Liu
- Beijing National Observatory of Space Environment; Institute of Geology and Geophysics, Chinese Academy of Sciences; Beijing China
| | - Biqiang Zhao
- Beijing National Observatory of Space Environment; Institute of Geology and Geophysics, Chinese Academy of Sciences; Beijing China
| | - Weixing Wan
- Beijing National Observatory of Space Environment; Institute of Geology and Geophysics, Chinese Academy of Sciences; Beijing China
| | - Baiqi Ning
- Beijing National Observatory of Space Environment; Institute of Geology and Geophysics, Chinese Academy of Sciences; Beijing China
| | - Man-Lian Zhang
- Beijing National Observatory of Space Environment; Institute of Geology and Geophysics, Chinese Academy of Sciences; Beijing China
| | - Maosheng He
- Beijing National Observatory of Space Environment; Institute of Geology and Geophysics, Chinese Academy of Sciences; Beijing China
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Jin H, Miyoshi Y, Fujiwara H, Shinagawa H. Electrodynamics of the formation of ionospheric wave number 4 longitudinal structure. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2008ja013301] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- H. Jin
- National Institute of Information and Communications Technology; Koganei, Tokyo Japan
| | - Y. Miyoshi
- Department of Earth and Planetary Sciences; Kyushu University; Fukuoka Japan
| | - H. Fujiwara
- Department of Geophysics, Graduate School of Science; Tohoku University; Sendai Japan
| | - H. Shinagawa
- National Institute of Information and Communications Technology; Koganei, Tokyo Japan
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