Bibliography

The origin of midlatitude plasma depletions detected during the 12 February 2000 and 29 October 2003 geomagnetic storms

Kil, Hyosub; Chang, Hyeyeon; Lee, Woo; Paxton, Larry; Sun, Andrew; Lee, Jiyun;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2022     DOI:

Ionospheric Disturbances in Low- and Midlatitudes During the Geomagnetic Storm on 26 August 2018

Plasma density depletions at midlatitudes during geomagnetic storms are often understood in terms of equatorial plasma bubbles (EPBs) due to their morphological similarity. However, our study reports the observations that reveal the generation of plasma depletions at midlatitudes by local sources. During the geomagnetic storm on 26 August 2018, the Defense Meteorological Satellite Program and Swarm satellites detected plasma depletions at midlatitudes in the Asian sector in the absence of EPBs in the equatorial region. This observation and the total electron content (TEC) maps over Japan demonstrate that traveling ionospheric disturbances (TIDs) are the sources of midlatitude plasma depletions in the Asian sector. Near the west coast of the United States, the development of a narrow TEC depletion band was identified from TEC maps. The TEC depletion band, which is elongated in the northwest–southeast direction, moves toward the west with a velocity of approximately 240 m/s. The TEC at the TEC depletion band is about 5 TEC units (1016 m−2) smaller than the ambient TEC. As this band is confined to the midlatitudes, this phenomenon is not associated with an EPB. The characteristics of the TEC depletion band are consistent with those of medium-scale TIDs. Observations in the Asian sector and the TEC depletion band over the United States demonstrate that plasma depletions can develop at midlatitudes by local sources. Therefore, the morphological similarity between midlatitude irregularities and EPBs or their coincident occurrence does not provide corroborating evidence of their connection.

Chang, Hyeyeon; Kil, Hyosub; Sun, Andrew; Zhang, Shun-Rong; Lee, Jiyun;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2022     DOI: 10.1029/2021JA029879

Retrospect and prospect of ionospheric weather observed by FORMOSAT-3/COSMIC and FORMOSAT-7/COSMIC-2

FORMOSAT-3/COSMIC (F3/C) constellation of six micro-satellites was launched into the circular low-earth orbit at 800 km altitude with a 72-degree inclination angle on 15 April 2006

Liu, Tiger; Lin, Charles; Lin, Chi-Yen; Lee, I-Te; Sun, Yang-Yi; Chen, Shih-Ping; Chang, Fu-Yuan; Rajesh, Panthalingal; Hsu, Chih-Ting; Matsuo, Tomoko; , others;

Published by: Terrestrial, Atmospheric and Oceanic Sciences      Published on:

YEAR: 2022     DOI: 10.1007/s44195-022-00019-x

Implication of Tidal Forcing Effects on the Zonal Variation of Solstice Equatorial Plasma Bubbles

Equatorial plasma bubbles (EPBs) are plasma depletions that can occur in the nighttime ionospheric F region, causing scintillation in satellite navigation and communications signals. Past research has shown that EPB occurrence rates are higher during the equinoxes in most longitude zones. An exception is over the central Pacific and African sectors, where EPB activity has been found to maximize during solstice. Tsunoda et al. (2015) hypothesized that the solstice maxima in these two sectors could be driven by a zonal wavenumber 2 atmospheric tide in the lower thermosphere. In this study, we utilize satellite observations to examine evidence of such a wave-2 feature preconditioning the nighttime ionosphere to favor higher EPB growth rates over these two regions. We find the postsunset total electron content (TEC) observed by FORMOSAT-3/COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) during boreal summer from 2007 to 2012 exhibits a wave-2 zonal distribution, consistent with elevated vertical plasma gradients favorable for EPB formation. Numerical experiments are also carried out to determine whether such an ionospheric wave-2 can be produced as a result of vertical coupling from atmospheric tides with zonal wavenumber 2 in the local time frame. We find that forcing from these tidal components produced increases in the Rayleigh-Taylor growth rate over both sectors during solar maximum and minimum, as well as wave-2 modulations on vertical ion drift, ion flux convergence, and nighttime TEC. Our results are consistent with the aforementioned hypothesis over both regions with vertical coupling effects from atmospheric tides preconditioning the nighttime ionosphere to favor higher EPB growth rates.

Chang, Loren; Salinas, Cornelius; Chiu, Yi-Chung; , Jones; Rajesh, P.; Chao, Chi-Kuang; Liu, Jann-Yenq; Lin, Charles; Hsiao, Tung-Yuan;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA028295

Ionosphere; Atmospheric tides; equatorial plasma bubble; scintillation; vertical coupling; wind dynamo

Planetary Waves and Their Impact on the Mesosphere, Thermosphere, and Ionosphere

Large-scale planetary waves (also known as Rossby waves), such as the Quasi-two day wave, 5 day wave and Kelvin wave, play crucial roles in coupling the lower and middle atmosphere to the mesosphere, thermosphere and ionosphere. Upward propagation and global structure of planetary waves in the stratosphere and mesosphere are affected by the zonal mean winds. Baroclinic or barotropic instability of the background mesospheric winds can amplify the waves en route to the upper atmosphere. Fast traveling planetary waves with deep vertical wavelengths, such as Kelvin waves, are able to reach the upper thermosphere and modulate air density and winds. More commonly, planetary waves influence the thermosphere-ionosphere system by modulating the E-region and F-region dynamo electric fields. Dissipation of planetary waves in the lower thermosphere modifies the background winds, and induces extra meridional circulation, consequently altering thermospheric constituents, such as O/N2, and ionospheric electron densities. Interactions between planetary waves and tides not only provide an additional source of traveling planetary waves in the mesosphere, but are key sources of variability in E-region dynamo electric fields and plasma drift.

Yue, Jia; Lieberman, Ruth; Chang, Loren;

Published by:       Published on:

YEAR: 2021     DOI: 10.1002/9781119815631.ch10

barotropic instability; E-region dynamo electric fields; F-region dynamo electric fields; Kelvin waves; mesosphere; planetary waves; plasma drift; thermosphere-ionosphere system

Plasma depletion bays in the equatorial ionosphere observed by FORMOSAT-3/COSMIC during 2007--2014

A new feature of plasma depletion bay (PDB) on the longitudinal structure over the equatorial and low latitudes is observed by the FORMOSAT-3/COSMIC (F3/C) electron density profiles. The existence of the PDB feature is confirmed by the OI 135.6 nm radiance from TIMED/GUVI, which together with F3/C electron density shows that one North PDB extending to the Southern Hemisphere prominently appears over Southwest America while three South PDBs extending to the Northern Hemisphere occur over North Atlantic, India Ocean, and Southeast Asia. Three-dimensional F3/C ionospheric electron densities are further used to examine PDB structures at various local times, seasons, solar activities, and altitudes during 2007−2014.

Chang, FY; Liu, JY; Fang, TW; Rajesh, PK; Lin, CH;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2020     DOI: 10.1029/2019JA027501

Modeling study of the ionospheric responses to the quasi-biennial oscillations of the sun and stratosphere

Reconstruction the Ionospheric Responses to the October-November 2003 Halloween Super Storm: A Data Assimilation Approach

Chang, Yu-Shan; Chen, Chia-Hung; Lin, Charles; Chu, Hung-Hsuan; Matsuo, Tomoko;

Published by:       Published on:

YEAR: 2018     DOI:

Tidal and Ionospheric Contributions in GUVI O/N2 wave-4 Signals and Implications for F-region Plasma Density Variability

Oberheide, Jens; Krier, Christopher; Gan, Quan; Nischal, Nirmal; Zhang, Yongliang; Chang, Loren;

Published by:       Published on:

YEAR: 2017     DOI:

Impacts of SABER CO ₂ -based eddy diffusion coefficients in the lower thermosphere on the ionosphere/thermosphere

This work estimates global-mean K_zz using Sounding of the Atmosphere using Broadband Emission Radiometry/Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics monthly global-mean CO₂ profiles and a one-dimensional transport model. It is then specified as a lower boundary into the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM). Results first show that global-mean CO₂ in the mesosphere and lower thermosphere region has annual and semiannual oscillations (AO and SAO) with maxima during solstice seasons along with a primary maximum in boreal summer. Our calculated AO and SAO in global-mean CO₂ are then modeled by AO and SAO in global-mean K_zz. It is then shown that our estimated global-mean K_zz is lower in magnitude than the suggested global-mean K_zz from Qian et al. (2009) that can model the observed AO and SAO in the ionosphere/thermosphere (IT) region. However, our estimated global-mean K_zz is similar in magnitude with recent suggestions of global-mean K_zz in models with explicit gravity wave parameterization. Our work therefore concludes that global-mean K_zz from global-mean CO₂ profiles cannot model the observed AO and SAO in the IT region because our estimated global-mean K_zz may only be representing eddy diffusion due to gravity wave breaking. The difference between our estimated global-mean K_zz and the global-mean K_zz from Qian et al. (2009) thus represents diffusion and mixing from other nongravity wave sources not directly accounted for in the TIE-GCM lower boundary conditions. These other sources may well be the more dominant lower atmospheric forcing behind the AO and SAO in the IT region.

Salinas, Cornelius; Chang, Loren; Liang, Mao-Chang; Yue, Jia; Russell, James; Mlynczak, Martin;

Published by: Journal of Geophysical Research: Space Physics      Published on: 11/2016

YEAR: 2016     DOI: 10.1002/2016JA023161

Coherent seasonal, annual, and quasi-biennial variations in ionospheric tidal/SPW amplitudes

In this study, we examine the coherent spatial and temporal modes dominating the variation of selected ionospheric tidal and stationary planetary wave (SPW) signatures from 2007 to 2013 FORMOSAT-3/COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) total electron content observations using multidimensional ensemble empirical mode decomposition (MEEMD) from the Hilbert-Huang Transform. We examine the DW1, SW2, DE3, and SPW4 components, which are driven by a variety of in situ and vertical coupling sources. The intrinsic mode functions (IMFs) resolved by MEEMD analysis allows for the isolation of the dominant modes of variability for prominent ionospheric tidal/SPW signatures in a manner not previously used, allowing the effects of specific drivers to be examined individually. The time scales of the individual IMFs isolated for all tidal/SPW signatures correspond to a semiannual variation at equatorial ionization anomaly (EIA) latitudes maximizing at the equinoxes, as well as annual oscillations at the EIA crests and troughs. All tidal/SPW signatures show one IMF isolating an ionospheric quasi-biennial oscillation (QBO) in the equatorial latitudes maximizing around January of odd-numbered years. This total electron content QBO variation is in phase with a similar QBO variation isolated in both the Global Ultraviolet Imager (GUVI) zonal mean column O/N₂ density ratio (ΣO/N₂) and the F_10.7 solar radio flux index around solar maximum, while showing temporal variation more similar to that of GUVI ΣO/N₂ during the time around the 2008/2009 extended solar minimum. These results point to both quasi-biennial variations in solar irradiance and thermosphere/ionosphere composition as a generation mechanism for the ionospheric QBO.

Chang, Loren; Sun, Yan-Yi; Yue, Jia; Wang, Jack; Chien, Shih-Han;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2016

YEAR: 2016     DOI: 10.1002/2015JA022249

Impacts of SABER CO2-based eddy diffusion coefficients in the lower thermosphere on the ionosphere/thermosphere

This work estimates global‐mean K zz using Sounding of the Atmosphere using Broadband Emission Radiometry/Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics

Salinas, Cornelius; Chang, Loren; Liang, Mao-Chang; Yue, Jia; , Russell; Mlynczak, Martin;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2016     DOI: 10.1002/2016JA023161

Observations of thermosphere and ionosphere changes due to the dissipative 6.5-day wave in the lower thermosphere

In the current work, temperature and wind data from the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite during the years 2002\textendash2007 were used to describe the seasonal variations of the westward propagating 6.5-day planetary wave in the mesosphere and lower thermosphere (MLT). Thermospheric composition data from the TIMED satellite and ionospheric total electron content (TEC) from the International Global Navigation Satellite System (GNSS) Service were then employed to carry out two case studies on the effect of this dissipating wave on the thermosphere/ionosphere. In both cases, there were westward anomalies of ~ 30\textendash40 m s-1\ in zonal wind in the MLT region that were caused by momentum deposition of the 6.5-day wave, which had peak activity during equinoxes. The westward zonal wind anomalies led to extra poleward meridional flows in both hemispheres. Meanwhile, there were evident overall reductions of thermospheric column density O / N2\ ratio and ionospheric TEC with magnitudes of up to 16\textendash24 \% during these two strong 6.5-day wave events. Based on the temporal correlation between O / N2\ and TEC reductions, as well as the extra poleward meridional circulations associated with the 6.5-day waves, we conclude that the dissipative 6.5-day wave in the lower thermosphere can cause changes in the thermosphere/ionosphere via the mixing effect, similar to the quasi-two-day wave (QTDW) as predicted by Yue and Wang (2014).

Gan, Q.; Yue, J.; Chang, L.; Wang, W.; Zhang, S.; Du, J.;

Published by: Annales Geophysicae      Published on: 01/2015

YEAR: 2015     DOI: 10.5194/angeo-33-913-2015

Quasi two day wave-related variability in the background dynamics and composition of the mesosphere/thermosphere and the ionosphere

Dissipating planetary waves in the mesosphere/lower thermosphere (MLT) region may cause changes in the background dynamics of that region, subsequently driving variability throughout the broader thermosphere/ionosphere system via mixing due to the induced circulation changes. We report the results of case studies examining the possibility of such coupling during the northern winter in the context of the quasi two day wave (QTDW)\textemdasha planetary wave that recurrently grows to large amplitudes from the summer MLT during the postsolstice period. Six distinct QTDW events between 2003 and 2011 are identified in the MLT using Sounding of the Atmosphere using Broadband Emission Radiometry temperature observations. Concurrent changes to the background zonal winds, zonal mean column O/N₂ density ratio, and ionospheric total electron content (TEC) are examined using data sets from Thermosphere Ionosphere Mesosphere Energetics and Dynamics Doppler Interferometer, Global Ultraviolet Imager, and Global Ionospheric Maps, respectively. We find that in the 5\textendash10 days following a QTDW event, the background zonal winds in the MLT show patterns of eastward and westward anomalies in the low and middle latitudes consistent with past modeling studies on QTDW-induced mean wind forcing, both below and at turbopause altitudes. This is accompanied by potentially related decreases in zonal mean thermospheric column O/N₂, as well as to low-latitude TECs. The recurrent nature of the above changes during the six QTDW events examined point to an avenue for vertical coupling via background dynamics and chemistry of the thermosphere/ionosphere not previously observed.

Chang, Loren; Yue, Jia; Wang, Wenbin; Wu, Qian; Meier, R.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2014

YEAR: 2014     DOI: 10.1002/jgra.v119.610.1002/2014JA019936

composition; Ionosphere; mesosphere; quasi two day wave; thermosphere

Correction of astigmatism and coma using analytic theory of aberrations in imaging spectrometer based on concentric off-axis dual reflector system

A specific imaging spectrometer based on a concentric off-axis dual reflector system is proposed, free of astigmatism and coma. The described imaging spectrometer consists of four spherical mirrors and a plane grating. The analytic theory of aberrations and the optical path-length concept are used to derive the astigmatism elimination and coma removal. It is shown that the astigmatism in these imaging spectrometers is eliminated by characterizing three angles, and the coma is corrected when unequal mirror radii are configured in collimating and condensing optics. The developed aberration principle is verified by comparing the performance of the astigmatism-eliminated spectrometer with the spectrometer which has neither astigmatism nor coma.

Chen, Ting; Tang, Yi; Zhang, Li; Chang, Yue; Zheng, Cheng;

Published by: Applied Optics      Published on: 01/2014

YEAR: 2014     DOI: 10.1364/AO.53.000565

On the fast zonal transport of the STS-121 space shuttle exhaust plume in the lower thermosphere

Meier et al. (2011) reported rapid eastward transport of the STS-121 space shuttle (launch: July 4, 2006) main engine plume in the lower thermosphere, observed in hydrogen Lyman α images by the GUVI instrument onboard the TIMED satellite. In order to study the mechanism of the rapid zonal transport, diagnostic tracer calculations are performed using winds from the Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model (TIME-GCM) simulation of July, 2006. It is found that the strong eastward jet at heights of 100\textendash110\ km, where the exhaust plume was deposited, results in a persistent eastward tracer motion with an average velocity of 45\ m/s. This is generally consistent with, though faster than, the prevailing eastward shuttle plume movement with daily mean velocity of 30\ m/s deduced from the STS-121 GUVI observation. The quasi-two-day wave (QTDW) was not included in the numerical simulation because it was found not to be large. Its absence, however, might be partially responsible for insufficient meridional transport to move the tracers away from the fast jet in the simulation. The current study and our model results from Yue and Liu (2010) explain two very different shuttle plume transport scenarios (STS-121 and STS-107 (launch: January 16, 2003), respectively): we conclude that lower thermospheric dynamics is sufficient to account for both very fast zonal motion (zonal jet in the case of STS-121) and very fast meridional motion to polar regions (large QTDW in the case of STS-107).

Yue, Jia; Liu, Han-Li; Meier, R.R.; Chang, Loren; Gu, Sheng-Yang; , Russell;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: Jan-03-2013

YEAR: 2013     DOI: 10.1016/j.jastp.2012.12.017

Modeling; thermosphere; Transport; Wind jet

Thermospheric tidal effects on the ionospheric midlatitude summer nighttime anomaly using SAMI3 and TIEGCM

This paper is the first study to employ a three-dimensional physics-based ionosphere model, SAMI3, coupled with the National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) and Global Scale Wave Model to simulate the mesospheric and lower thermospheric tidal effects on the development of midlatitude summer nighttime anomaly (MSNA). Using this coupled model, the diurnal variation of MSNA electron densities at 300 km altitude is simulated on both June solstice (day of year (DOY) 167) and December solstice (DOY 350) in 2007. Results show successful reproduction of the southern hemisphere MSNA structure including the eastward drift feature of the southern MSNA, which is not reproduced by the default SAMI3 runs using the neutral winds provided by the empirical Horizontal Wind Model 93 neutral wind model. A linear least squares algorithm for extracting tidal components is utilized to examine the major tidal component affecting the variation of southern MSNA. Results show that the standing diurnal oscillation component dominates the vertical neutral wind manifesting as a diurnal eastward wave-1 drift of the southern MSNA in the local time frame. We also find that the stationary planetary wave-1 component of vertical neutral wind can cause diurnal variation of the summer nighttime electron density enhancement around the midlatitude ionosphere.

Chen, C.; Lin, C.; Chang, L.; Huba, J.; Lin, J.; Saito, A.; Liu, J;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2013

YEAR: 2013     DOI: 10.1002/jgra.50340

MSNA; SAMI3; tidal effect; TIEGCM

Plasma Depletion Bay in the Summer Nighttime Equatorial Ionosphere

Chang, F; Liu, JG;

Published by:       Published on:

YEAR: 2013     DOI:

Observations of global ionospheric responses to the 2009 stratospheric sudden warming event by FORMOSAT-3/COSMIC

The global ionospheric response to a stratospheric sudden warming (SSW) is studied using three-dimensional electron density maps derived from radio occultation observations of FORMOSAT-3/COSMIC during the 2009 SSW periods. Results show that the ionospheric electron density at EIA crests exhibit a morning/early afternoon increase followed by an afternoon decrease and an evening increase, indicative of a semidiurnal component during the SSW period, which is consistent with recent studies. The latitude-altitude electron density slice maps show that the SSW related modifications of the equatorial plasma fountain interact with the existing summer-to-winter neutral winds and resulting in a north\textendashsouth asymmetry. The global ionospheric response shows a clear longitudinal dependence in the equatorial plasma fountain enhancement during morning/early afternoon, inferred from the duration of the equatorial ionization anomaly (EIA) enhancement. Following the enhancement, prominent global EIA reductions resulting from the equatorial plasma fountain weakening in the afternoon sector are seen. The ionospheric response to the 2009 SSW event is also compared with the usual seasonal variation during January\textendashFebruary 2007. Instead of showing the electron density increase in the northern hemisphere and decrease in the southern hemisphere as the usual seasonal variation does, the SSW period ionosphere shows prominent global electron density reductions in the afternoon period during the 2009 SSW event.

Lin, C.; Lin, J.; Chang, L.; Liu, J; Chen, C.; Chen, W.; Huang, H.; Liu, C.;

Published by: Journal of Geophysical Research      Published on: 06/2012

YEAR: 2012     DOI: 10.1029/2011JA017230

FORMOSAT-3/COSMIC; ionospheric responses to stratospheric sudden warming

Global Ionospheric Structure Imaged by FORMOSAT-3/COSMIC: Early Results.

A new era of study ing the ion o spheric space weather ef fects has come af ter launch of the in no va tive sat el lite con stel la tion, named as Formosa Sat el lite 3 or Con stel la tion Ob

Lin, Chien-Hung; Liu, Jann-Yenq; Hsiao, Chun-Chieh; Liu, Chao-Han; Cheng, Chio-Zong; Chang, Po-Ya; Tsai, Ho-Fang; Fang, Tzu-Wei; Chen, Chia-Hung; Hsu, Mei-Lan;

Published by: Terrestrial, Atmospheric \& Oceanic Sciences      Published on:

YEAR: 2009     DOI:

First terrestrial soft X-ray auroral observation by the Chandra X-ray Observatory

Bhardwaj, Anil; Gladstone, Randall; Elsner, Ronald; Ostgaard, Nikolai; Waite, Hunter; Cravens, Thomas; Chang, Shen-Wu; Majeed, Tariq; Metzger, Albert;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: Jan-02-2007

YEAR: 2007     DOI: 10.1016/j.jastp.2006.07.011

Motions of the equatorial ionization anomaly crests imaged by FORMOSAT-3/COSMIC

Lin, C.; Liu, J; Fang, T.; Chang, P; Tsai, H.; Chen, C.; Hsiao, C.;

Published by: Geophysical Research Letters      Published on: Jan-01-2007

YEAR: 2007     DOI: 10.1029/2007GL030741