Bibliography

Validation of in-situ ionospheric density using FORMOSAT-7/COSMIC-2 IVM and ICON IVM

We investigate the validation of in-situ ion density measurements by the ion velocity meter (IVM) onboard F7/C2 and ICON, respectively, during the solar minimum condition of

Choi, Jong-Min; Lin, Charles; Rajesh, PK; Park, Jaeheung; Kwak, Young-Sil; Chen, Shih-Ping; Lin, Jia-Ting;

Published by:       Published on:

YEAR: 2022     DOI: 10.21203/rs.3.rs-1758637/v1

Validation of in-situ ionospheric density using FORMOSAT-7/COSMIC-2 IVM and ICON IVM

We investigate the validation of in-situ ion density measurements by the ion velocity meter (IVM) onboard F7/C2 and ICON, respectively, during the solar minimum condition of

Choi, Jong-Min; Lin, Charles; Rajesh, PK; Park, Jaeheung; Kwak, Young-Sil; Chen, Shih-Ping; Lin, Jia-Ting;

Published by:       Published on:

YEAR: 2022     DOI: 10.21203/rs.3.rs-1758637/v1

Satellite In Situ Electron Density Observations of the Midlatitude Storm Enhanced Density on the Noon Meridional Plane in the F Region During the 20 November 2003 Magnetic Storm

Ionospheric storm enhanced density (SED) has been extensively investigated using total electron content deduced from GPS ground and satellite-borne receivers. However, dayside in situ electron density measurements have not been analyzed in detail for SEDs yet. We report in situ electron density measurements of a SED event in the Northern Hemisphere (NH) at the noon meridian plane measured by the Challenging Minisatellite Payload (CHAMP) polar-orbiting satellite at about 390 km altitude during the 20 November 2003 magnetic storm. The CHAMP satellite measurements render rare documentation about the dayside SED s life cycle at a fixed magnetic local time (MLT) through multiple passes. Solar wind drivers triggered the SED onset and controlled its lifecycle through its growth and retreat phases. The SED electron density enhancement extended from the equatorial ionization anomaly to the noon cusp. The midlatitude electron density increased to a maximum at the end of the growth phase. Afterward, the dayside SED region retreated gradually to lower magnetic latitudes. The observations showed a hemisphere asymmetry, with the NH electron density exhibiting a more significant enhancement. The simulations using the Thermosphere Ionosphere Electrodynamic General Circulation model show a good agreement with the CHAMP observations. The simulations indicate that the dayside midlatitude electron density enhancement has a complicated dependence on vertical ion drift, neutral wind, magnetic latitude, MLT, and the height of the F2 layer. Finally, we discuss the notion of using the mean cross-polar cap electric field as a proxy for assessing the effects of solar wind drivers on producing midlatitude electron density enhancement.

Lin, Chin; Sutton, Eric; Wang, Wenbin; Cai, Xuguang; Liu, Guiping; Henney, Carl; Cooke, David;

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

YEAR: 2022     DOI: 10.1029/2021JA029831

in situ plasma density; ionospheric electron density; prompt penetration electric field; Storm enhanced density; tongue of ionization

Sounding Rocket Observation of Nitric Oxide in the Polar Night

An altitude profile of Nitric Oxide (NO) in the 80–110 km altitude range was measured in the polar night from a sounding rocket on 27 January 2020. The observations were made using the technique of stellar occultation with a UV spectrograph observing the γ (1,0) band of NO near 215 nm. The tangent point for the altitude profile was at 74° latitude, a location that had been in darkness for 80 days. The retrieved slant column density profile is interpreted using an assumed four-parameter analytic profile shape. Retrievals of the fitting parameters yield a profile with a peak NO concentration of 2.2 ± 0.7 × 108 cm−3 at 93.5 ± 4.1 km. The observations were made during a time of minimum solar and geomagnetic activity. The NO maximum retrieved from the rocket profile is significantly larger in abundance and lower in altitude than other observations on the same day at nearby latitudes just outside the polar night. These rocket-borne results are consistent with NO that is created over the course over the polar winter and is confined to high latitudes in the polar night by the mesospheric polar vortex. During the course of that confinement the abundance increases due to the lack of photodissociation, allowing the NO to descend. We show that the observed descent can be explained by eddy diffusion-driven transport, though vertical advection cannot be ruled out.

Bailey, Scott; McClintock, William; Carstens, Justin; Thurairajah, Brentha; Das, Saswati; Randall, Cora; Harvey, Lynn; Siskind, David; Stevens, Michael; Venkataramani, Karthik;

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

YEAR: 2022     DOI: 10.1029/2021JA030257

Lower thermosphere; mesosphere; nitric oxide; polar night; sounding rocket; stellar occultation

Interhemispheric Asymmetries in Ionospheric Electron Density Responses During Geomagnetic Storms: A Study Using Space-Based and Ground-Based GNSS and AMPERE Observations

We utilize Total Electron Content (TEC) measurements and electron density (Ne) retrieval profiles from Global Navigation Satellite System (GNSS) receivers onboard multiple Low Earth Orbit (LEO) satellites to characterize large-scale ionosphere-thermosphere system responses during geomagnetic storms. We also analyze TEC measurements from GNSS receivers in a worldwide ground-based network. Measurements from four storms during June and July 2012 (boreal summer months), December 2015 (austral summer month), and March 2015 (equinoctial month) are analyzed to study global ionospheric responses and the interhemispheric asymmetry of these responses. We find that the space-based and ground-based TECs and their responses are consistent in all four geomagnetic storms. The global 3D view from GNSS-Radio Occultation (RO) Ne observations captures enhancements and the uplifting of Ne structures at high latitudes during the initial and main phases. Subsequently, Ne depletion occurs at high latitudes and starts progressing into midlatitude and low latitude as the storm reaches its recovery phase. A clear time lag is evident in the storm-induced Ne perturbations at high latitudes between the summer and winter hemispheres. The interhemispheric asymmetry in TEC and Ne appears to be consistent with the magnitudes of the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) high latitude integrated field-aligned currents (FACs), which are 3–4 MA higher in the summer hemisphere than in the winter hemisphere during these storms. The ionospheric TEC and Ne responses combined with the AMPERE-observed FACs indicate that summer preconditioning in the ionosphere-thermosphere system plays a key role in the interhemispheric asymmetric storm responses.

Swarnalingam, N.; Wu, D.; Gopalswamy, N.;

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

YEAR: 2022     DOI: 10.1029/2021JA030247

Coordinated Observations of Rocket Exhaust Depletion: GOLD, Madrigal TEC, and Multiple Low-Earth-Orbit Satellites

A plasma density hole was created in the ionosphere by a rocket launch from Cape Canaveral, Florida near local sunset on 30 August 2020, which is called rocket exhaust depletion (RED). The hole persisted for several hours into the night and was observed in total electron content (TEC) maps, the Global-scale Observations of the Limb and Disk (GOLD) imager, and multiple low-earth-orbit satellites. The RED created a nightglow pit in the GOLD 135.6 nm image. Swarm satellites found that the RED exhibited insignificant changes in electron/ion temperature and field-aligned currents. On the other hand, magnetic field strength was enhanced inside the RED by a few tenths of a nanotesla. Assimilation data products of the Constellation Observing System for Meteorology, Ionosphere, and Climate 2 (COSMIC-2) mission reveal that ionospheric slab thickness increased at the center of the RED, which is supported by combined analyses of the GOLD and TEC data. The RED did not host conspicuous substructures that are stronger and longer-lasting than the ambient plasma did.

Park, Jaeheung; Rajesh, P.; Ivarsen, Magnus; Lin, Charles; Eastes, Richard; Chao, Chi; Coster, Anthea; Clausen, Lasse; Burchill, Johnathan;

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

YEAR: 2022     DOI: 10.1029/2021JA029909

GOLD; Madrigal TEC; COSMIC-2; Norsat-1; rocket exhaust depletion; swarm

Behaviors of Ionospheric Topside Ion Density, Ion Temperature, and Electron Temperature During the 20 November 2003 Superstorm

We identified a few new storm‐time ionospheric phenomena by analyzing disturbances in topside ion density, electron temperature, and ion temperature at ∼840 km altitude measured

Huang, Chao-Song; Zhang, Yongliang; Wang, Wenbin; Lin, Dong; Wu, Qian;

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

YEAR: 2022     DOI: 10.1029/2022JA030468

Satellite in-situ electron density observations of the midlatitude storm enhanced density on the noon meridional plane in the F region during the 20 November 2003 magnetic storm

The GUVI measurements indicated that the atomic oxygen (O) to molecular nitrogen (N2) (2021a) used the TIMED/GUVI limb measurements and TIEGCM simulations to investigate

Lin, Chin; Sutton, Eric; Wang, Wenbin; Cai, Xuguang; Liu, Guiping; Henney, Carl; Cooke, David;

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

YEAR: 2022     DOI: 10.1029/2021JA029831

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

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

Echo occurrence in the southern polar ionosphere for the SuperDARN Dome C East and Dome C North radars

In this paper, echo occurrence rates for the Dome C East (DCE) and the new Dome C North (DCN) radars are studied. We report the ionospheric and ground scatter echo occurrence rates for selected periods around equinoxes and solstices in the final part of the solar cycle XXIV. The occurrence maps built in Altitude Adjusted Corrected Geomagnetic latitude and Magnetic Local Time coordinates show peculiar patterns highly variable with season. The comparisons of the radar observations with the International Reference Ionosphere model electron density and with ray tracing simulations allow us to explain the major features of observed patterns in terms of electron density variations. The study shows the great potential of the DCE and DCN radar combination to the Super Dual Auroral Radar Network (SuperDARN) convection mapping in terms of monitoring key regions of the high-latitude ionosphere critical for understanding of the magnetospheric dynamics.

Marcucci, Maria; Coco, Igino; Massetti, Stefano; Pignalberi, Alessio; Forsythe, Victoriya; Pezzopane, Michael; Koustov, Alexander; Longo, Simona; Biondi, David; Simeoli, Enrico; Consolini, Giuseppe; Laurenza, Monica; Marchaudon, Aurélie; Satta, Andrea; Cirioni, Alessandro; De Simone, Angelo; Olivieri, Angelo; Baù, Alessandro; Salvati, Alberto;

Published by: Polar Science      Published on: jun

YEAR: 2021     DOI: 10.1016/j.polar.2021.100684

Echo occurrence; IRI model; Polar cap radars; Ray-tracing

Longitudinal variations of geomagnetic and ionospheric parameters in the Northern Hemisphere during magnetic storms according to multi-instrument observations

We present a joint analysis of longitude-temporal variations of ionospheric and geomagnetic parameters at middle and high latitudes in the Northern Hemisphere during the two severe magnetic storms in March and June 2015 by using data from the chains of magnetometers, ionosondes and GPS/GLONASS receivers. We identify the fixed longitudinal zones where the variability of the magnetic field is consistently high or low under quiet and disturbed geomagnetic conditions. The revealed longitudinal structure of the geomagnetic field variability in quiet geomagnetic conditions is caused by the discrepancy of the geographic and magnetic poles and by the spatial anomalies of different scales in the main magnetic field of the Earth. Variations of ionospheric parameters are shown to exhibit a pronounced longitudinal inhomogeneity with changing geomagnetic conditions. This inhomogeneity is associated with the longitudinal features of background and disturbed structure of the geomagnetic field. During the recovery phase of a storm, important role in dynamics of the mid-latitude ionosphere may belong to wave-like thermospheric disturbances of molecular gas, propagating westward for several days. Therefore, it is necessary to extend the time interval for studying the ionospheric effects of strong magnetic storms by a few days after the end of the magnetospheric source influence, while the disturbed regions in the thermosphere continues moving westward and causes the electron density decrease along the trajectories of propagation.

Chernigovskaya, M.; Shpynev, B.; Yasyukevich, A.; Khabituev, D.; Ratovsky, K.; Belinskaya, Yu.; Stepanov, A.; Bychkov, V.; Grigorieva, S.; Panchenko, V.; Kouba, D.; Mielich, J.;

Published by: Advances in Space Research      Published on: jan

YEAR: 2021     DOI: 10.1016/j.asr.2020.10.028

Chain of GPS/GLONASS receivers; Geomagnetic field variations; geomagnetic storm; Ionosonde chain; ionospheric disturbances

The Dynamics of the Alfvénic Oval

The auroral oval is a well-established concept, introduced more than five decades ago. The Alfvénic oval, on the other hand, is a very recent concept, which has been revealed in both observational and numerical studies. This is the first review of the global Alfvénic oval, while also defining primary, secondary and tertiary layers of the Alfvénic oval. The focus lies on the large-scale dynamic properties of the global Alfvénic oval in relation to the AE index, substorm phases, storm phases and solar wind/IMF conditions. Statistical data recorded above and below the nominal auroral acceleration region are reviewed, together with results from global simulation studies. The Alfvénic oval s relation to the auroral oval is also reviewed. This review demonstrates that the Alfvénic oval is well enough defined and investigated to give it its name, and it demonstrates that our understanding allows for the prediction of the Alfvénic oval under various conditions.

Keiling, Andreas;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: aug

YEAR: 2021     DOI: 10.1016/j.jastp.2021.105616

AURORA; Alfven wave; Energy transport; geomagnetic activity; magnetosphere-ionosphere coupling; Wave-particle interaction

Near Real-Time Global Plasma Irregularity Monitoring by FORMOSAT-7/COSMIC-2

This study presents initial results of the ionospheric scintillation in the F layer using the S4 index derived from the radio occultation experiment (RO-S4) on FORMOSAT-7/COSMIC-2 (F7/C2). With the sufficiently dense RO-S4 observations at low latitudes, it is possible to construct hourly, global scintillation maps to monitor equatorial plasma bubbles (EPBs). The preliminary F7/C2 RO-S4 during August 2019 to April 2020 show clear scintillation distributions around American and the Atlantic Ocean longitudes. The RO-S4 near Jicamarca are compared with range-time-intensity (RTI) maps of the 50 MHz radar, and the results show that the occurrence of intense RO-S4 in the range 0.125–0.5 are co-located with the bottomside of the spread-F patterns. Increases in RO-S4 at the upward phase of bottom-side oscillations is theoretically consistent with large-scale wave seeding of the EPBs. The locations and occurrences of the RO-S4 greater than 0.5 are consistent with airglows depletions from the NASA GOLD mission. Climatology analyses show that monthly occurrences of RO-S4 \textgreater 0.5 agree well with the monthly EPB occurrences in GOLD 135.6 nm image, and show a similar longitudinal distribution to that of DMSP and C/NOFS in-situ measurements. The results suggest that the RO-S4 intensities can be utilized to identify EPBs of specific scales.

Chen, Shih-Ping; Lin, Charles; Rajesh, Panthalingal; Liu, Jann-Yenq; Eastes, Richard; Chou, Min-Yang; Choi, Jong-Min;

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

YEAR: 2021     DOI: 10.1029/2020JA028339

equatorial plasma bubbles; FORMOSAT-7/COSMIC-2; global observation of limb and disk; GNSS scintillation; radio occultation; S4 index

Transpolar Arcs During a Prolonged Radial Interplanetary Magnetic Field Interval

Transpolar arcs (TPAs) are believed to predominantly occur under northward interplanetary magnetic field (IMF) conditions with their hemispheric asymmetry controlled by the Sun-Earth (radial) component of the IMF. In this study, we present observations of TPAs that appear in both the northern and southern hemispheres even during a prolonged interval of radially oriented IMF. The Defense Meteorological Satellite Program (DMSP) F16 and the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellites observed TPAs on the dawnside polar cap in both hemispheres (one TPA structure in the southern hemisphere and two in the northern hemisphere) during an interval of nearly earthward-oriented IMF on October 29, 2005. The southern hemisphere TPA and one of the northern hemisphere TPAs are associated with electron and ion precipitation and mostly sunward plasma flow (with shears) relative to their surroundings. Meanwhile, the other TPA in the northern hemisphere is associated with an electron-only precipitation and antisunward flow relative to its surroundings. Our observations indicate the following: (a) the TPA formation is not limited to northward IMF conditions; (b) the TPAs can be located on both closed field lines rooted in the polar cap of both hemispheres and open field lines connected to the northward field lines draped over one hemisphere of the magnetopause. We believe that the TPAs presented here are the result of both indirect and direct processes of solar wind energy transfer to the high-latitude ionosphere.

Park, Jong-Sun; Shi, Quan; Nowada, Motoharu; Shue, Jih-Hong; Kim, Khan-Hyuk; Lee, Dong-Hun; Zong, Qiu-Gang; Degeling, Alexander; Tian, An; Pitkänen, Timo; Zhang, Yongliang; Rae, Jonathan; Hairston, Marc;

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

YEAR: 2021     DOI: 10.1029/2021JA029197

radial IMF; solar wind-magnetosphere-ionosphere coupling; transpolar arc

Extreme Positive Ionosphere Storm Triggered by a Minor Magnetic Storm in Deep Solar Minimum Revealed by FORMOSAT-7/COSMIC-2 and GNSS Observations

This study examines an unexpected and extreme positive ionospheric response to a minor magnetic storm on August 5, 2019 by using global ionosphere specification (GIS) 3D electron density profiles obtained by assimilating radio occultation total electron content (TEC) measurements of the recently launched FORMOSAT-7/COSMIC-2 satellites, and ground-based global navigation satellite system (GNSS) TEC. The results reveal ∼300\% enhancement of equatorial ionization anomaly (EIA) crests, appearing over 200–300 km altitudes, and a much intense localized density enhancement over the European sector. These are the most intense ionospheric response that has ever been detected for a small magnetic storm with Dst ∼ −53 nT (SYM-H ∼ −64 nT). The enhancements are validated by using global ionosphere map (GIM) TEC and ground-based GNSS TEC. The GIS vertical electron density structures during the storm are examined to understand the physical processes giving rise to such an intense ionosphere response during deep solar minimum conditions when the background electron density is very low. Altitude variations and poleward shifts of the locations of the EIA crests indicate that prompt penetration electric fields (PPEF) play an important role in producing the observed positive storm responses, with the storm-induced equatorward circulation supporting the plasma accumulation against recombination losses. Additional physical mechanisms are required to fully explain the unexpected electron density enhancements for this minor storm event.

Rajesh, P.; Lin, C.; . Y. Lin, C; Chen, C.; . Y. Liu, J; Matsuo, T.; Chen, S.; Yeh, W.; . Y. Huang, C;

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

YEAR: 2021     DOI: 10.1029/2020JA028261

FORMOSAT-7/COSMIC-2; Global Ionospheric Specification; ionospheric data assimilation; ionospheric response to magnetic storm; magnetosphere-ionosphere coupling; minor magnetic storm

Extreme Positive Ionosphere Storm Triggered by a Minor Magnetic Storm in Deep Solar Minimum Revealed by FORMOSAT-7/COSMIC-2 and GNSS Observations

This study examines an unexpected and extreme positive ionospheric response to a minor magnetic storm on August 5, 2019 by using global ionosphere specification (GIS) 3D electron density profiles obtained by assimilating radio occultation total electron content (TEC) measurements of the recently launched FORMOSAT-7/COSMIC-2 satellites, and ground-based global navigation satellite system (GNSS) TEC. The results reveal ∼300\% enhancement of equatorial ionization anomaly (EIA) crests, appearing over 200–300 km altitudes, and a much intense localized density enhancement over the European sector. These are the most intense ionospheric response that has ever been detected for a small magnetic storm with Dst ∼ −53 nT (SYM-H ∼ −64 nT). The enhancements are validated by using global ionosphere map (GIM) TEC and ground-based GNSS TEC. The GIS vertical electron density structures during the storm are examined to understand the physical processes giving rise to such an intense ionosphere response during deep solar minimum conditions when the background electron density is very low. Altitude variations and poleward shifts of the locations of the EIA crests indicate that prompt penetration electric fields (PPEF) play an important role in producing the observed positive storm responses, with the storm-induced equatorward circulation supporting the plasma accumulation against recombination losses. Additional physical mechanisms are required to fully explain the unexpected electron density enhancements for this minor storm event.

Rajesh, P.; Lin, C.; . Y. Lin, C; Chen, C.; . Y. Liu, J; Matsuo, T.; Chen, S.; Yeh, W.; . Y. Huang, C;

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

YEAR: 2021     DOI: 10.1029/2020JA028261

FORMOSAT-7/COSMIC-2; Global Ionospheric Specification; ionospheric data assimilation; ionospheric response to magnetic storm; magnetosphere-ionosphere coupling; minor magnetic storm

Thermospheric Composition and Solar EUV Flux From the Global-Scale Observations of the Limb and Disk (GOLD) Mission

Observations of far-ultraviolet (FUV) dayglow by the Global-scale Observations of Limb and Disk (GOLD) mission provide a new opportunity to monitor relative composition changes in the upper atmosphere as well as solar extreme ultraviolet (EUV) variability. Relative composition changes are quantified by ΣO/N2, the column density ratio of atomic oxygen to molecular nitrogen, while QEUV provides a measure of the solar EUV energy flux from 1 to 45 nm into the upper atmosphere. This spectral range provides the ionizing radiation which ultimately results in FUV airglow emission produced by photodissociation and photoelectron impact. The quantities ΣO/N2 and QEUV are derived from GOLD FUV observations through lookup tables that are constructed using a first-principles photoelectron transport model. The two FUV emissions used are O I 135.6 nm and the N2 Lyman-Birge-Hopfield (LBH) bands. We present an overview of the theoretical basis for the algorithms and practical considerations for application to GOLD data. The effects of uncertainties in electron impact cross sections, off-nadir viewing, and instrument artifacts are reviewed. We also discuss GOLD Level 1C DAY, Level 2 data products ON2 and QEUV, and present representative samples of each.

Correira, J.; Evans, J.; Lumpe, J.; Krywonos, A.; Daniell, R.; Veibell, V.; McClintock, W.; Eastes, R.;

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

YEAR: 2021     DOI: 10.1029/2021JA029517

GOLD; neutral composition; ON2; QEUV; radiative recombination; thermosphere

First Comparison of Traveling Atmospheric Disturbances Observed in the Middle Thermosphere by Global-Scale Observations of the Limb and Disk to Traveling Ionospheric Disturbances Seen in Ground-Based Total Electron Content Observations

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

Ionosphere; thermosphere; airglow; atmospheric waves

Low-Latitude Zonal Ion Drifts and Their Relationship With Subauroral Polarization Streams and Auroral Return Flows During Intense Magnetic Storms

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

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

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

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

Temporal evolution of substorm-driven global Alfv\ en wave power above the auroral acceleration region

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

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

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:

YEAR: 2020     DOI:

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

First zonal drift velocity measurement of Equatorial Plasma Bubbles (EPBs) from a geostationary orbit using GOLD data

Karan, Deepak; Daniell, Robert; England, Scott; Martinis, Carlos; Eastes, Richard; Burns, Alan; McClintock, William;

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

YEAR: 2020     DOI:

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:

YEAR: 2020     DOI:

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:

YEAR: 2020     DOI:

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:

YEAR: 2020     DOI:

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

The seasonal and longitudinal variations of nighttime OI 135.6-nm emission at equatorial ionization anomaly crests observed by the DMSP/SSUSI

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

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

Consequences of a solar wind stream interaction region on the low latitude ionosphere: event of 7 October 2015

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

Global-scale observations and modeling of far-ultraviolet airglow during twilight

The NASA Global‐scale Observations of the Limb and Disk ultraviolet imaging spectrograph performs observations of upper atmosphere airglow from the sunlit disk and limb of the Earth

Solomon, Stanley; Andersson, Laila; Burns, Alan; Eastes, Richard; Martinis, Carlos; McClintock, William; Richmond, Arthur;

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

YEAR: 2020     DOI: 10.1029/2019JA027645

Daily Variability in the Terrestrial UV Airglow

New capability for observing conditions in the upper atmosphere comes with the implementation of global ultraviolet (UV) imaging from geosynchronous orbit. Observed by the NASA

Immel, Thomas; Eastes, Richard; McClintock, William; Mende, Steven; Frey, Harald; Triplett, Colin; England, Scott;

Published by: Atmosphere      Published on:

YEAR: 2020     DOI: 10.3390/atmos11101046

A new data set of thermospheric molecular oxygen from the Global-scale Observations of the Limb and Disk (GOLD) mission

The Global-scale Observations of the Limb and Disk (GOLD) instrument was launched on 25 January 2018 onboard the SES-14 commercial communications satellite and began nominal science operations in October 2018. Operating from geostationary orbit at 47.5°W longitude, GOLD images the Earth s thermosphere and ionosphere in the far-ultraviolet (132–162 nm), measuring critical geophysical parameters by continuously scanning the Earth s disk and limb 18 hours per day. GOLD also performs stellar occultation measurements using bright type O and B stars.

Lumpe, JD; McClintock, WE; Evans, JS; Correira, J; , Veibell; Beland, S; Eastes, R;

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

YEAR: 2020     DOI: 10.1029/2020JA027812

Global-scale Observations of the Equatorial Ionization Anomaly

Abstract The National Aeronautics and Space Administration Global-scale Observations of the Limb and Disk ultraviolet spectrograph has been imaging the equatorial ionization anomaly (EIA), regions of the ionosphere with enhanced electron density north and south of the magnetic equator, since October 2018. The initial 3 months of observations was during solar minimum conditions, and they included observations in December solstice of unanticipated variability and depleted regions. Depletions are seen on most nights, in contrast to expectations from previous space-based observations. The variety of scales and morphologies also pose challenges to understanding of the EIA. Abrupt changes in the EIA location, which could be related to in situ measurements of large-scale depletion regions, are observed on some nights. Such synoptic-scale disruptions have not been previously identified.

Eastes, R.; Solomon, S.; Daniell, R.; Anderson, D.; Burns, A.; England, S.; Martinis, C.; McClintock, W.;

Published by: Geophysical Research Letters      Published on:

YEAR: 2019     DOI: https://doi.org/10.1029/2019GL084199

Equatorial ionosphere; ionospheric irregularities; ionospheric dynamics; Ionospheric storms; forecasting; airglow and aurora

Simulation of ionospheric behavior in the Eastern Asia during magnetic storm on March 17--19, 2015

Based on numerical model of the ionosphere and plasmasphere, we simulated behavior of the ionospheric parameters during the main phase of the 17 March 2015 St. Patrick’s Day

Tashchilin, AV;

Published by:       Published on:

YEAR: 2019     DOI: 10.1117/12.2540705

Energy Transfer in the Solar Wind-Magnetosphere-Ionosphere System Under Radial Interplanetary Magnetic Field Conditions: Implication of Transpolar Arcs

Park, Jong-Sun; Shi, Quanqi; Nowada, Motoharu; Shue, Jih-Hong; Kim, Khan-Hyuk; Lee, Dong-Hun; Zong, Qiugang; Degeling, Alexander; Tian, Anmin; Pitkänen, Timo; , others;

Published by:       Published on:

YEAR: 2019     DOI:

Composition Changes Around the Equinoxes

Burns, Alan; Cai, Xuguang; Wang, Wenbin; Qian, Liying; Zhang, Yongliang; Eastes, Richard; McClintock, William;

Published by:       Published on:

YEAR: 2019     DOI:

Small structural differences between two ferrocenyl diphenols determine large discrepancies of reactivity and biological effects

Tonolo, Federica; Salmain, Michèle; Scalcon, Valeria; Top, Siden; Pigeon, Pascal; Folda, Alessandra; Caron, Benoit; Mcglinchey, Michael; Toillon, Robert-Alain; Bindoli, Alberto; , others;

Published by: ChemMedChem      Published on:

YEAR: 2019     DOI:

The ionosphere response to severe geomagnetic storm in March 2015 on the base of the data from Eurasian high-middle latitudes ionosonde chain

Comparison of the Thermospheric Nitric Oxide Emission Observations and the GITM Simulations: Sensitivity to Solar and Geomagnetic Activities

An accurate estimate of the energy budget (heating and cooling) of the ionosphere and thermosphere, especially during space weather events, has been a challenge. The abundance of Nitric Oxide (NO), a minor species in the thermosphere, is an important component of energy balance here because its production comes from energy sources able to break the strong bond of molecular nitrogen, and infrared emissions from NO play an important role in thermospheric cooling. Recent studies have significantly improved our understanding of NO chemistry and its relationship to energy deposition in the thermospheric photochemical reactions. In this study, the chemical scheme in the Global Ionosphere Thermosphere Model (GITM) is updated to better predict the lower thermospheric NO responses to solar and geomagnetic activity. We investigate the sensitivity of the 5.3-micron NO emission to F10.7 and Ap indices by comparing the global integrated emission from GITM with an empirical proxy derived from the Sounding of the Atmosphere using Broadband Emission Radiometry measurements. GITM\textquoterights total emission agrees well within 20\% of the empirical values. The updated chemistry scheme significantly elevates the level of integrated emission compared to the previous scheme. The inclusion of N2(A)-related production of NO contributes an additional 5-25\% to the emission. Localized enhancement of ~70\% in column density and a factor of three in column emission are simulated at a moderate geomagnetic level.

Lin, Cissi; Deng, Yue; Venkataramani, Karthik; Yonker, Justin; Bailey, Scott;

Published by: Journal of Geophysical Research: Space Physics      Published on: 10/2018

YEAR: 2018     DOI: 10.1029/2018JA025310

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

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

Global-scale Observations of the Limb and Disk (GOLD): science implementation

McClintock, William; Eastes, Richard; Andersson, Laila; Burns, Alan; Codrescu, Mihail; Daniell, Robert; England, Scott; Evans, Scott; Krywonos, Andrey; Lumpe, Jerry; , others;

Published by:       Published on:

YEAR: 2018     DOI:

How might the thermosphere and ionosphere react to an extreme space weather event?

This chapter explores how the thermosphere and ionosphere (T-I) might respond to extreme solar events. Three different scenarios are considered: (1) an increase in solar UV and EUV radiation for a number of days, (2) an extreme enhancement in the solar X-rays and EUV radiation associated with a flare, and (3) an extreme CME driving a geomagnetic storm. Estimating the response to the first two scenarios is reasonably well defined, and although they would certainly impact the T-I system, those impacts could potentially be mitigated. In contrast, the response to an extreme geomagnetic storm is significantly more complicated, making the response much more uncertain, and mitigation more challenging.

Fuller-Rowell, Tim; Emmert, John; Fedrizzi, Mariangel; Weimer, Daniel; Codrescu, Mihail; Pilinski, Marcin; Sutton, Eric; Viereck, Rodney; Raeder, Joachim; Doornbos, Eelco;

Published by:       Published on:

YEAR: 2018     DOI: 10.1016/B978-0-12-812700-1.00021-2

Comparison of the Thermospheric Nitric Oxide Emission Observations and the Global Ionosphere-Thermosphere Model (GITM) Simulations: Sensitivity to Solar and Geomagnetic Activities

The magnitude of enhancement observed in column density agrees well with the cases observed by TIMED/GUVI −8 W/m3) agree well with TIMED/SABER and GUVI measurements.

Lin, Cissi; Deng, Yue; Venkataramani, Karthik; Yonker, Justin; Bailey, Scott;

Published by: arXiv preprint arXiv:1807.01380      Published on:

YEAR: 2018     DOI: https://doi.org/10.48550/arXiv.1807.01380