Bibliography
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Found 672 entries in the Bibliography.
Showing entries from 101 through 150
| 2021 |
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The geomagnetic storm that occurred on 25 August 25 2018, that is, during the minimum of solar cycle 24, is currently the strongest ever probed by the first China Seismo-Electromagnetic Satellite (CSES-01). By integrating the in situ measurements provided by CSES-01 (orbiting at altitude of 507 km) and by Swarm A satellite (orbiting at ca., 460 km) with ground-based observations (ionosondes, magnetometers, and Global Navigation Satellite System receivers), we investigate the ionospheric response at lower- and mid-latitudes over Brazil. Specifically, we investigate the electrodynamic disturbances driven by solar wind changes, by focusing on the disturbances driving modifications of the equatorial electrojet (EEJ). Our proposed multisensor technique analysis mainly highlights the variations in the topside and bottomside ionosphere, and the interplay between prompt penetrating electric fields and disturbance dynamo electric fields resulting in EEJ variations. Thanks to this approach and leveraging on the newly available CSES-01 data, we complement and extend what recently investigated in the Western South American sector, by highlighting the significant longitudinal differences, which mainly come from the occurrence of a daytime counter-EEJ during both 25 and 26 August at Braziliian longitudes and during part of 26 August only in the Peruvian sector. In addition, the increased thermospheric circulation driven by the storm has an impact on the EEJ during the recovery phase of the storm. The observations at the CSES-01/Swarm altitudes integrated with the ground-based observation recorded signatures of equatorial ionospheric anomaly crests formation and modification during daytime coupled with the positive ionospheric storm effects at midlatitude. Spogli, L.; Sabbagh, D.; Regi, M.; Cesaroni, C.; Perrone, L.; Alfonsi, L.; Di Mauro, D.; Lepidi, S.; Campuzano, S.; Marchetti, D.; De Santis, A.; Malagnini, A.; Scotto, C.; Cianchini, G.; Shen, Xu; Piscini, A.; Ippolito, A.; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2021 DOI: 10.1029/2020JA028368 Geomagnetic storms; Equatorial Electrojet; in situ plasma density; ionospheric elctroduamics; Ionospheric storms; low-latitude ionosphere |
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Traveling ionospheric disturbances (TIDs) and their neutral counterparts known as traveling atmospheric disturbances (TADs) are believed to play a role in communicating inputs to other locations in the fluid. While these two phenomena are believed to be connected, they may not have a one-to-one correspondence as the geomagnetic field influences the TID but has no direct impact on the TAD. The relative amplitudes of the perturbations seen in the ionosphere and atmosphere have been observed but rarely together. This study reports results from a 3-day campaign to observe TIDs and TADs simultaneously over a broad latitudinal region over the eastern United States using a combination of Global-scale Observations of the Limb and Disk (GOLD) and a distributed network of ground-based Global Navigation Satellite System (GNSS) receivers. These results demonstrate that GOLD and the ground-based total electron content (TEC) observations can see the atmospheric and ionospheric portions of a large-scale traveling disturbance. The phase difference in the perturbations to the GOLD airglow brightness, O/N2 and thermospheric disk temperature are consistent with an atmospheric gravity wave moving through this region. The ionospheric signatures move at the same rate as those in the atmosphere, but their amplitudes do not have a simple correspondence to the amplitude of the signal seen in the atmosphere. This campaign demonstrates a proof-of-concept that this combination of observations is able to provide information on TIDs and TADs, including quantifying their impact on the temperature and chemical composition of the upper atmosphere. England, Scott; Greer, Katelynn; Zhang, Shun-Rong; Evans, Scott; Solomon, Stanley; Eastes, Richard; McClintock, William; Burns, Alan; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2021 DOI: 10.1029/2021JA029248 |
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We analyze horizontal plasma drifts measured by the Defense Meteorological Satellite Program satellites during two intense magnetic storms. It is found, for the first time, that westward plasma flows associated with subauroral polarization streams (SAPS) in the dusk-evening sector penetrate continuously to equatorial latitudes. The westward ion drifts between subauroral and equatorial latitudes occur nearly simultaneously. The latitudinal profile of the westward ion drifts at low latitudes (approximately within ±30° magnetic latitude [MLat]) is relatively flat, and the westward ion drifts at the magnetic equator reach 200–300 m s−1. In the dawn-morning sector, eastward ion drifts at subauroral latitudes are also SAPS. The storm-time dawnside auroral boundary moves to ∼±55° MLat, and the dawnside SAPS penetrate to ∼±20° MLat at 0930 local time. A dawnside SAPS flow channel appears to exist, although it is not as well defined as the duskside SAPS flow channel. Thermospheric wind data measured by the Challenging Minisatellite Payload satellite are analyzed, and zonal disturbance winds are derived. Disturbance winds can reach equatorial latitudes rapidly near midnight but are limited to ±40° geographic latitude or higher near noon. The effects of disturbance winds on the zonal ion drifts at middle and low latitudes are discussed. It is suggested that both the westward ion drifts at middle and low latitudes in the dusk-evening sector and the eastward ion drifts at middle and lower latitudes in the dawn-morning sector are caused primarily by penetration of the SAPS and auroral electric fields. Huang, Chao-Song; Zhang, Yongliang; Wang, Wenbin; Lin, Dong; Wu, Qian; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2021 DOI: 10.1029/2021JA030001 Electric field; Ionosphere; ionospheric plasma drift; penetration electric field; Subauroral Polarization Streams; thermospheric wind |
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Global Effects of a Polar Solar Eclipse on the Coupled Magnetosphere-Ionosphere System It is well-known that solar eclipses can significantly impact the ionosphere and thermosphere, but how an eclipse influences the magnetosphere-ionosphere system is still unknown. Using a coupled magnetosphere-ionosphere-thermosphere model, we examined the impact on geospace of the northern polar-region eclipse that occurred on June 10, 2021. The simulations reveal that the eclipse-induced reduction in polar ionospheric conductivity causes large changes in field-aligned current, cross-polar cap potential and auroral activity. While such effects are expected in the northern hemisphere where solar obscuration occurred, they also occurred in the southern hemisphere through electrodynamic coupling. Eclipse-induced changes in monoenergetic auroral precipitation differ significantly between the northern hemisphere and southern hemisphere while diffuse auroral precipitation is interhemispherically symmetric. This study demonstrates that the geospace response to a polar-region solar eclipse is not limited just to the eclipse region but has global implications. Chen, Xuetao; Dang, Tong; Zhang, Binzheng; Lotko, William; Pham, Kevin; Wang, Wenbin; Lin, Dong; Sorathia, Kareem; Merkin, Viacheslav; Luan, Xiaoli; Dou, Xiankang; Luo, Bingxian; Lei, Jiuhou; Published by: Geophysical Research Letters Published on: YEAR: 2021 DOI: 10.1029/2021GL096471 auroral activity; magnetosphere-ionosphere coupling; polar solar eclipse |
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SABER Observation of Storm-Time Hemispheric Asymmetry in Nitric Oxide Radiative Emission The nitric oxide (NO) 5.3 μm radiative emission is the dominating and most efficient cooling agent in the thermosphere above 100 km. The NO 5.3 μm radiative cooling is an important Bag, Tikemani; Li, Zheng; Rout, Diptiranjan; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2021 DOI: 10.1029/2020JA028849 |
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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 |
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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 |
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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 |
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We present an analysis of the ionosphere and thermosphere response to Solar Proton Events (SPE) and magnetospheric proton precipitation in January 2005, which was carried out Bessarab, Fedor; Sukhodolov, Timofei; Klimenko, Maxim; Klimenko, Vladimir; Korenkov, Yu; Funke, Bernd; Zakharenkova, Irina; Wissing, Jan; Rozanov, EV; Published by: Advances in Space Research Published on: YEAR: 2021 DOI: 10.1016/j.asr.2020.10.026 |
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We present an analysis of the ionosphere and thermosphere response to Solar Proton Events (SPE) and magnetospheric proton precipitation in January 2005, which was carried out Bessarab, Fedor; Sukhodolov, Timofei; Klimenko, Maxim; Klimenko, Vladimir; Korenkov, Yu; Funke, Bernd; Zakharenkova, Irina; Wissing, Jan; Rozanov, EV; Published by: Advances in Space Research Published on: YEAR: 2021 DOI: 10.1016/j.asr.2020.10.026 |
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Recent attention has been given to mesoscale phenomena across geospace (∼10 s km to 500 km in the ionosphere or ∼0.5 RE to several RE in the magnetosphere), as their contributions to the system global response are important yet remain uncharacterized mostly due to limitations in data resolution and coverage as well as in computational power. As data and models improve, it becomes increasingly valuable to advance understanding of the role of mesoscale phenomena contributions—specifically, in magnetosphere-ionosphere coupling. This paper describes a new method that utilizes the 2D array of Time History of Events and Macroscale Interactions during Substorms (THEMIS) white-light all-sky-imagers (ASI), in conjunction with meridian scanning photometers, to estimate the auroral scale sizes of intense precipitating energy fluxes and the associated Hall conductances. As an example of the technique, we investigated the role of precipitated energy flux and average energy on mesoscales as contrasted to large-scales for two back-to-back substorms, finding that mesoscale aurora contributes up to ∼80\% (∼60\%) of the total energy flux immediately after onset during the early expansion phase of the first (second) substorm, and continues to contribute ∼30–55\% throughout the remainder of the substorm. The average energy estimated from the ASI mosaic field of view also peaked during the initial expansion phase. Using the measured energy flux and tables produced from the Boltzmann Three Constituent (B3C) auroral transport code (Strickland et al., 1976; 1993), we also estimated the 2D Hall conductance and compared it to Poker Flat Incoherent Scatter Radar conductance values, finding good agreement for both discrete and diffuse aurora. Gabrielse, Christine; Nishimura, Toshi; Chen, Margaret; Hecht, James; Kaeppler, Stephen; Gillies, Megan; Reimer, Ashton; Lyons, Larry; Deng, Yue; Donovan, Eric; Evans, Scott; Published by: Frontiers in Physics Published on: |
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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 |
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We use the \textlessi\textgreateram\textlessi/\textgreater, \textlessi\textgreateran, as\textlessi/\textgreater and the \textlessi\textgreateraσ\textlessi/\textgreater geomagnetic indices to the explore a previously overlooked factor in magnetospheric electrodynamics, namely the inductive effect of diurnal motions of the Earth’s magnetic poles toward and away from the Sun caused by Earth’s rotation. Because the offset of the (eccentric dipole) geomagnetic pole from the rotational axis is roughly twice as large in the southern hemisphere compared to the northern, the effects there are predicted to be roughly twice the amplitude of those in the northern hemisphere. Hemispheric differences have previously been discussed in terms of polar ionospheric conductivities generated by solar photoionization, effects which we allow for by looking at the dipole tilt effect on the time-of-year variations of the indices. The electric field induced in a geocentric frame is shown to also be a significant factor and gives a modulation of the voltage applied by the solar wind flow in the southern hemisphere that is typically a ±30\% diurnal modulation for disturbed intervals rising to ±76\% in quiet times. For the northern hemisphere these are 15\% and 38\% modulations. Motion away from/towards the Sun reduces/enhances the directly-driven ionospheric voltages and reduces/enhances the magnetic energy stored in the tail and we estimate that approximately 10\% of the effect appears in directly driven ionospheric voltages and 90\% in changes of the rate of energy storage or release in the near-Earth tail. The hemispheric asymmetry in the geomagnetic pole offsets from the rotational axis is shown to be the dominant factor in driving Universal Time (\textlessi\textgreaterUT\textlessi/\textgreater) variations and hemispheric differences in geomagnetic activity. Combined with the effect of solar wind dynamic pressure and dipole tilt on the pressure balance in the near-Earth tail, the effect provides an excellent explanation of how the observed Russell-McPherron pattern with time-of-year \textlessi\textgreaterF\textlessi/\textgreater and \textlessi\textgreaterUT\textlessi/\textgreater in the driving power input into the magnetosphere is converted into the equinoctial \textlessi\textgreaterF\textlessi/\textgreater-\textlessi\textgreaterUT\textlessi/\textgreater pattern in average geomagnetic activity (after correction is made for dipole tilt effects on ionospheric conductivity), added to a pronounced \textlessi\textgreaterUT\textlessi/\textgreater variation with minimum at 02–10 UT. In addition, we show that the predicted and observed \textlessi\textgreaterUT\textlessi/\textgreater variations in average geomagnetic activity has implications for the occurrence of the largest events that also show the nett \textlessi\textgreaterUT\textlessi/\textgreater variation. Lockwood, Mike; Haines, Carl; Barnard, Luke; Owens, Mathew; Scott, Chris; Chambodut, Aude; McWilliams, Kathryn; Published by: Journal of Space Weather and Space Climate Published on: YEAR: 2021 DOI: 10.1051/swsc/2020077 |
| 2020 |
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Multi-scale ionosphere responses to the May 2017 magnetic storm over the Asian sector We investigate multi-scale ionospheric responses to the May 27, 2017, geomagnetic storm over the Asian sector by using multi-instrumental observations, including ground-based global navigation satellite systems (GNSS) network, constellation observing system for meteorology, ionosphere and climate radio occultation, the FengYun-3C (FY-3C) GNSS occultation sounder electron density profiles and in situ plasma density observations provided by both Swarm and defense meteorological satellite program missions. This geomagnetic storm was an intense storm with the minimum symmetric horizontal component reaching - 150\ nT and was caused by a coronal mass ejection released on May 23. The main observations are summarized below: (1) two ionospheric positive storm periods were observed. The first one was observed in the noon\textendashafternoon sector during the main phase of the storm on May 28, with nearly 120\% TEC enhancement. The second one was of a smaller scale and occurred on the nightside during the recovery phase of the storm on May 29. The first dayside positive storm was initiated by the interplanetary magnetic field (IMF) Bz southward turning and eastward penetration electric field, while the second nightside one was terminated by a later southward turning of the IMF Bz since the Asian sector was on the nightside and the penetration electric field changed westward. (2) A negative storm occurred from 00:00 to 12:00 UT on May 30 over the Asian sector, nearly 2\ days after the main phase, which was due to the thermospheric composition change, i.e., decrease in the O/N2 ratio, as shown in the TIMED/GUVI measurements. (3) A band-like TEC enhancement was observed aligning in the northwest\textendashsoutheast direction and propagated slowly southwestward from 15:00 to 20:00 UT (23:00\textendash04:00 LT, near midnight) on May 28 during the recovery phase of the storm. In situ density observations from the Swarm B and DMSP F15\&16 satellites confirmed the density enhancement at 510\ km and 850\ km, respectively, and revealed that this band-like TEC enhancement structure resembles the so-called plasma blob. The similarities of the observed plasma blob characteristics in terms of spatial structure, propagation trend and temporal evolution with the nighttime traveling ionospheric disturbance (TID) are consistent with the TID-blob theory. Liu, Lei; Zou, Shasha; Yao, Yibin; Aa, Ercha; Published by: GPS Solutions Published on: 12/2019 YEAR: 2020 DOI: 10.1007/s10291-019-0940-1 Blob structure; Positive and negative ionosphere responses; TID; Geomagnetic storms |
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The onset of substorms is associated with bursty enhancements of Alfv\ en wave power throughout the magnetotail. While impossible to assess the total Alfv\ en wave power in the entire magnetotail, we have instead monitored waves that are funneled into the auroral acceleration region, in order to assess the temporal evolution of Alfv\ en wave power above the nightside auroral zone in relation to substorm phases. The substorms were grouped by three conditions: nonstorm periods, storm periods, and all (unconditioned) periods. Using superposed epoch analysis, we found that the global magnetohydrodynamic Alfv\ en wave power increased significantly at onset for all three conditions, while a power decrease to pre-onset values occurred within 2 h. Specifically, the peak inflowing power during the expansion phase was 5.7 GW for unconditioned substorms, 5.6 GW for nonstorm-time substorms, and 7.8 GW for storm-time substorms. These results correspond to power increases with respect to pre-onset values of 138\%, 366\%, and 200\%, respectively. Additional analysis in relation to the aurora was performed for nonstorm-time substorms only. During the expansion phase, about 50\% of the Alfv\ en wave power over the entire nightside auroral zone is collocated with the auroral bulge region. Furthermore, the total inflowing Alfv\ en wave power over the entire nightside auroral zone is 17\% of the conjugate auroral power, while the inflowing power over the auroral bulge region is 32\% of the conjugate aurora. However, allowing for a finite absorption efficiency inside the auroral acceleration region, the likely average Alfv\ enic contributions to the aurora are approximately 10\% and 18\%,respectively. Keiling, Andreas; Thaller, Scott; Dombeck, John; Wygant, John; Published by: Journal of Geophysical Research: Space Physics Published on: 03/2020 YEAR: 2020 DOI: 10.1029/2019JA027444 Alfven wave; Alfvenic electron; AURORA; auroral acceleration; magnetotail; Substorm |
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Modeled IMF B y Effects on the Polar Ionosphere and Thermosphere Coupling There is still an inadequate understanding of how the interplanetary magnetic field (IMF) east-west component (By) affects thermospheric composition, and other ionospheric and thermospheric fields in a systematic way. Utilizing the state-of-art first-principles Coupled Magnetosphere Ionosphere Thermosphere (CMIT) modeling and TIMED/Global Ultraviolet Imager (GUVI)-observed ΣO/N2 covering an entire solar cycle (year 2002\textendash2016), as well as a neutral parcel trajectory tracing technique, we emphasize that not only the direction of By, but also its strength relative to the IMF north-south component (Bz) that has important effects on high latitude convection, Joule heating, electron density, neutral winds, and neutral composition patterns in the upper thermosphere. The Northern Hemisphere convection pattern becomes more twisted for positive By cases than negative cases: the dusk cell becomes more rounded compared with the dawn cell. Consequently, equatorward neutral winds are stronger during postmidnight hours in negative By cases than in positive By cases, creating a favorable condition for neutral composition disturbances (characterized by low ΣO/N2) to expand to lower latitudes. This may lead to a more elongated ΣO/N2 depletion area along the morning-premidnight direction for negative By conditions compared with the positive By conditions. Backward neutral parcel trajectories indicate that a lower ΣO/N2 parcel in negative By cases comes from lower altitudes, as compared with that for positive By cases, leading to larger enhancements of N2 in the former case. Liu, Jing; Burns, Alan; Wang, Wenbin; Zhang, Yongliang; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2020 YEAR: 2020 DOI: 10.1029/2019JA026949 |
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Real-Time Thermospheric Density Estimation via Two-Line Element Data Assimilation Inaccurate estimates of the thermospheric density are a major source of error in low Earth orbit prediction. Therefore, real-time density estimation is required to improve orbit prediction. In this work, we develop a dynamic reduced-order model for the thermospheric density that enables real-time density estimation using two-line element (TLE) data. For this, the global thermospheric density is represented by the main spatial modes of the atmosphere and a time-varying low-dimensional state and a linear model is derived for the dynamics. Three different models are developed based on density data from the TIE-GCM, NRLMSISE-00, and JB2008 thermosphere models and are valid from 100 to maximum 800 km altitude. Using the models and TLE data, the global density is estimated by simultaneously estimating the density and the orbits and ballistic coefficients of several objects using a Kalman filter. The sequential estimation provides both estimates of the density and corresponding uncertainty. Accurate density estimation using the TLEs of 17 objects is demonstrated and validated against CHAMP and GRACE accelerometer-derived densities. The estimated densities are shown to be significantly more accurate and less biased than NRLMSISE-00 and JB2008 modeled densities. The uncertainty in the density estimates is quantified and shown to be dependent on the geographical location, solar activity, and objects used for estimation. In addition, the data assimilation capability of the model is highlighted by assimilating CHAMP accelerometer-derived density data together with TLE data to obtain more accurate global density estimates. Finally, the dynamic thermosphere model is used to forecast the density. Gondelach, David; Linares, Richard; Published by: Space Weather Published on: 01/2020 YEAR: 2020 DOI: 10.1029/2019SW002356 density estimation; reduced-order modeling; satellite drag; thermospheric density modeling; two-line element data |
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Understanding the Behavior of the Ionosphere—Thermosphere—Mesosphere at Solar Minimum I Paxton, Larry; Deng, Yue; Liu, Huixin; Fang, Tzu-Wei; Published by: Published on: |
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Seasonal variation of O/N2 on different pressure levels from GUVI limb measurements Yu, Tingting; Ren, Zhipeng; Le, Huijun; Wan, Weixing; Wang, Wenbin; Cai, Xuguang; Li, Xing; Published by: Journal of Geophysical Research: Space Physics Published on: |
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Neutral exospheric temperatures from the GOLD mission Evans, JS; Lumpe, JD; Correira, J; , Veibell; Kyrwonos, A; McClintock, WE; Solomon, SC; Eastes, RW; Published by: Journal of Geophysical Research: Space Physics Published on: |
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Hemispheric asymmetry of the dayside aurora due to imbalanced solar insolation Liou, Kan; Mitchell, Elizabeth; Published by: Scientific Reports Published on: |
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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 |
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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 |
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Li, Qiaoling; Huang, Fuqing; Zhong, Jiahao; Zhang, Ruilong; Kuai, Jiawei; Lei, Jiuhou; Liu, Libo; Ren, Dexin; Ma, Han; Yoshikawa, Akimasa; , others; Published by: Journal of geophysical research: space physics Published on: |
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Li, Qiaoling; Huang, Fuqing; Zhong, Jiahao; Zhang, Ruilong; Kuai, Jiawei; Lei, Jiuhou; Liu, Libo; Ren, Dexin; Ma, Han; Yoshikawa, Akimasa; , others; Published by: Journal of geophysical research: space physics Published on: |
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Wang, Zihan; Zou, Shasha; Ren, Jiaen; Aa, Ercha; Liu, Lei; Published by: Published on: |
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Karan, Deepak; Daniell, Robert; England, Scott; Martinis, Carlos; Eastes, Richard; Burns, Alan; McClintock, William; Published by: Journal of Geophysical Research: Space Physics Published on: |
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Immel, Thomas; Greer, Katelynn; Lieberman, Ruth; Paxton, Larry; Published by: Published on: |
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Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Brückner, Marlen; Lonardi, Michael; Ehrlich, Andr\; Wendisch, Manfred; Jäkel, Evelyn; Schäfer, Michael; Quaas, Johannes; Kalesse, Heike; Published by: Published on: |
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Immel, Thomas; Greer, Katelynn; Lieberman, Ruth; Paxton, Larry; Published by: Published on: |
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Paxton, Larry; Provornikova, Elena; Roelof, Edmond; emerais, Eric; Izmodenov, Vladislav; Katushkina, Olga; Mierkiewicz, Edwin; Baliukin, Igor; Gruntman, Mike; Taguchi, Makoto; , others; Published by: Published on: |
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Lissa, D; Srinivasu, VKD; Prasad, DSVVD; Niranjan, K; Published by: Advances in Space Research Published on: |
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A comparison of thermospheric FUV radiance and composition from TIMED, GOLD and ICON Zhang, Y; Paxton, LJ; Schaefer, RK; Eastes, R; McClintock, WE; Immel, TJ; Published by: Published on: |
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Variations of lower thermospheric FUV emissions based on GOLD observations and GLOW modeling Greer, KR; Eastes, Richard; Solomon, Stan; McClintock, William; Burns, Alan; Rusch, David; Published by: Journal of Geophysical Research: Space Physics Published on: |
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Modeled IMF By effects on the polar ionosphere and thermosphere coupling Liu, Jing; Burns, Alan; Wang, Wenbin; Zhang, Yongliang; Published by: Journal of Geophysical Research: Space Physics Published on: |
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O 2 aurora is one kind of important molecular aurorae that is not fully understood yet. It is hard to be investigated due to the contamination by nightglow. In this work, we studied O 2 Gao, Hong; Xu, JiYao; Chen, Guang-Ming; Zhu, Yajun; Liu, Weijun; Wang, Chi; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2020JA028302 |
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First results of UV radiation measurements made by AURA detector onboard VDNH-80 cubesat GUVI experiment data Chernov, DV; Glinkin, EV; Klimov, PA; Murashov, AS; Published by: Advances in the Astronautical Sciences Published on: |
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First results of UV radiation measurements made by AURA detector onboard VDNH-80 cubesat GUVI experiment data Chernov, DV; Glinkin, EV; Klimov, PA; Murashov, AS; Published by: Advances in the Astronautical Sciences Published on: |
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In this paper we provide a comprehensive comparison of in situ electron density (Ne) and temperature (Te) measured by Langmuir probe (LAP) on board the China Seismo‐ Yan, Rui; Zhima, Zeren; Xiong, Chao; Shen, Xuhui; Huang, Jianping; Guan, Yibing; Zhu, Xinghong; Liu, Chao; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2019JA027747 |
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Prominent daytime TEC enhancements under the quiescent condition of January 2017 UltraViolet Imager (GUVI) for the longitude and latitude bins of 30 and 10, respectively. However, as shown in Figure 3c, the O/N 2 ratio from Global UltraViolet Imager (GUVI) had no Huang, Fuqing; Lei, Jiuhou; Zhang, Ruilong; Li, Na; Gu, Shengyang; Yu, You; Liu, Libo; Owolabi, Charles; Ning, Baiqi; Li, Guozhu; , others; Published by: Geophysical Research Letters Published on: YEAR: 2020 DOI: 10.1029/2020GL088398 |
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Prominent daytime TEC enhancements under the quiescent condition of January 2017 UltraViolet Imager (GUVI) for the longitude and latitude bins of 30 and 10, respectively. However, as shown in Figure 3c, the O/N 2 ratio from Global UltraViolet Imager (GUVI) had no Huang, Fuqing; Lei, Jiuhou; Zhang, Ruilong; Li, Na; Gu, Shengyang; Yu, You; Liu, Libo; Owolabi, Charles; Ning, Baiqi; Li, Guozhu; , others; Published by: Geophysical Research Letters Published on: YEAR: 2020 DOI: 10.1029/2020GL088398 |
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Prominent daytime TEC enhancements under the quiescent condition of January 2017 UltraViolet Imager (GUVI) for the longitude and latitude bins of 30 and 10, respectively. However, as shown in Figure 3c, the O/N 2 ratio from Global UltraViolet Imager (GUVI) had no Huang, Fuqing; Lei, Jiuhou; Zhang, Ruilong; Li, Na; Gu, Shengyang; Yu, You; Liu, Libo; Owolabi, Charles; Ning, Baiqi; Li, Guozhu; , others; Published by: Geophysical Research Letters Published on: YEAR: 2020 DOI: 10.1029/2020GL088398 |
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Comparison of GOLD nighttime measurements with total electron content: Preliminary results The National Aeronautics and Space Administration (NASA) Global‐scale Observations of the Limb and Disk (GOLD) has been imaging the thermosphere and ionosphere since Cai, Xuguang; Burns, Alan; Wang, Wenbin; Coster, Anthea; Qian, Liying; Liu, Jing; Solomon, Stanley; Eastes, Richard; Daniell, Robert; McClintock, William; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2019JA027767 |
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Comparison of GOLD nighttime measurements with total electron content: Preliminary results The National Aeronautics and Space Administration (NASA) Global‐scale Observations of the Limb and Disk (GOLD) has been imaging the thermosphere and ionosphere since Cai, Xuguang; Burns, Alan; Wang, Wenbin; Coster, Anthea; Qian, Liying; Liu, Jing; Solomon, Stanley; Eastes, Richard; Daniell, Robert; McClintock, William; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2019JA027767 |
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the South American longitudinal sector, which was also observed by GUVI data (Kil et al., 2004); This result was also observed by GUVI in Kil et al. (2004), ROCSAT-1 in Y. Chen et al. Guo, Bing; Xu, JiYao; Sun, Longchang; Lin, Yingjun; Yuan, Wei; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2019JA027764 |
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Recent ionospheric investigations in China (2018—2019) (a) and (c) TIMED/GUVI data superimposed on the 557.7 nm ASI data at 19:55 UT and 21:33 UT, and the overpass of DMSP F13 crossing the PCA superimposed on the image, shown Published by: Earth and Planetary Physics Published on: YEAR: 2020 DOI: 10.26464/epp2020028 |
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Initial observations by the GOLD mission Given that previous measurements of ΔΣO/N 2 from low Earth orbit (LEO) have proven invaluable in advancing our understanding of the TI system (eg, TIMED/GUVI), GOLD data have Eastes, RW; McClintock, WE; Burns, AG; Anderson, DN; Andersson, L; Aryal, S; Budzien, SA; Cai, X; Codrescu, MV; Correira, JT; , others; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2020JA027823 |
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The auroral oval boundary represents an important physical process with implications for the ionosphere and magnetosphere. An automatic auroral oval boundary prediction method Han, Yiyuan; Han, Bing; Hu, Zejun; Gao, Xinbo; Zhang, Lixia; Yang, Huigen; Li, Bin; Published by: Nonlinear Processes in Geophysics Published on: YEAR: 2020 DOI: 10.5194/npg-27-11-2020 |
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This paper focuses on unique aspects of the ionospheric response at conjugate locations over Europe and South Africa during the 7–8 September 2017 geomagnetic storm including Habarulema, John; Katamzi-Joseph, Zama; a, Dalia; Nndanganeni, Rendani; Matamba, Tshimangadzo; Tshisaphungo, Mpho; Buchert, Stephan; Kosch, Michael; Lotz, Stefan; Cilliers, Pierre; , others; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2020JA028307 |
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In this article, we present a study of the perturbations occurring in the Earth’s environment on 7 October 2015. We use a multi-instrument approach, including space and ground Molina, Maria; Dasso, S; Mansilla, G; Namour, Jorge; Cabrera, Miguel; Zuccheretti, Enrico; Published by: Solar Physics Published on: YEAR: 2020 DOI: 10.1007/s11207-020-01728-7 |