Bibliography

Pronounced Suppression and X-Pattern Merging of Equatorial Ionization Anomalies After the 2022 Tonga Volcano Eruption

Following the 2022 Tonga Volcano eruption, dramatic suppression and deformation of the equatorial ionization anomaly (EIA) crests occurred in the American sector ∼14,000 km away from the epicenter. The EIA crests variations and associated ionosphere-thermosphere disturbances were investigated using Global Navigation Satellite System total electron content data, Global-scale Observations of the Limb and Disk ultraviolet images, Ionospheric Connection Explorer wind data, and ionosonde observations. The main results are as follows: (a) Following the eastward passage of expected eruption-induced atmospheric disturbances, daytime EIA crests, especially the southern one, showed severe suppression of more than 10 TEC Unit and collapsed equatorward over 10° latitudes, forming a single band of enhanced density near the geomagnetic equator around 14–17 UT, (b) Evening EIA crests experienced a drastic deformation around 22 UT, forming a unique X-pattern in a limited longitudinal area between 20 and 40°W. (c) Thermospheric horizontal winds, especially the zonal winds, showed long-lasting quasi-periodic fluctuations between ±200 m/s for 7–8 hr after the passage of volcano-induced Lamb waves. The EIA suppression and X-pattern merging was consistent with a westward equatorial zonal dynamo electric field induced by the strong zonal wind oscillation with a westward reversal.

Aa, Ercha; Zhang, Shun-Rong; Wang, Wenbin; Erickson, Philip; Qian, Liying; Eastes, Richard; Harding, Brian; Immel, Thomas; Karan, Deepak; Daniell, Robert; Coster, Anthea; Goncharenko, Larisa; Vierinen, Juha; Cai, Xuguang; Spicher, Andres;

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

YEAR: 2022     DOI: 10.1029/2022JA030527

EIA suppression and X-pattern; Equatorial ionization anomaly; GNSS TEC; GOLD UV images; ICON MIGHTI neutral wind; Tonga volcano eruption

The nighttime ionospheric response and occurrence of equatorial plasma irregularities during geomagnetic storms: a case study

Recent studies revealed that the long-lasting daytime ionospheric enhancements of Total Electron Content (TEC) were sometimes observed in the Asian sector during the recovery phase of geomagnetic storms (e.g., Lei (J Geophys Res Space Phys 123: 3217–3232, 2018), Li (J Geophys Res Space Phys 125: e2020JA028238, 2020). However, they focused only on the dayside ionosphere, and no dedicated studies have been performed to investigate the nighttime ionospheric behavior during such kinds of storm recovery phases. In this study, we focused on two geomagnetic storms that happened on 7–8 September 2017 and 25–26 August 2018, which showed the prominent daytime TEC enhancements in the Asian sector during their recovery phases, to explore the nighttime large-scale ionospheric responses as well as the small-scale Equatorial Plasma Irregularities (EPIs). It is found that during the September 2017 storm recovery phase, the nighttime ionosphere in the American sector is largely depressed, which is similar to the daytime ionospheric response in the same longitude sector; while in the Asian sector, only a small TEC increase is observed at nighttime, which is much weaker than the prominent daytime TEC enhancement in this longitude sector. During the recovery phase of the August 2018 storm, a slight TEC increase is observed on the night side at all longitudes, which is also weaker than the prominent daytime TEC enhancement. For the small-scale EPIs, they are enhanced and extended to higher latitudes during the main phase of both storms. However, during the recovery phases of the first storm, the EPIs are largely enhanced and suppressed in the Asian and American sectors, respectively, while no prominent nighttime EPIs are observed during the second storm recovery phase. The clear north–south asymmetry of equatorial ionization anomaly crests during the second storm should be responsible for the suppression of EPIs during this storm. In addition, our results also suggest that the dusk side ionospheric response could be affected by the daytime ionospheric plasma density/TEC variations during the recovery phase of geomagnetic storms, which further modulates the vertical plasma drift and plasma gradient. As a result, the growth rate of post-sunset EPIs will be enhanced or inhibited.

Wan, Xin; Xiong, Chao; Gao, Shunzu; Huang, Fuqing; Liu, Yiwen; Aa, Ercha; Yin, Fan; Cai, Hongtao;

Published by: Satellite Navigation      Published on: nov

YEAR: 2021     DOI: 10.1186/s43020-021-00055-x

Equatorial plasma irregularity; Geomagneitc storm; Ionospheric response; longitudinal variations; Storm recovery phase

Comparison of ionospheric anomalies over African equatorial/low-latitude region with IRI-2016 model predictions during the maximum phase of solar cycle 24

The capability of IRI-2016 in reproducing the hemispheric asymmetry, the winter and semiannual anomalies has been assessed over the equatorial ionization anomaly (EIA) during quiet periods of years 2013–2014. The EIA reconstructed using Total Electron Content (TEC) derived from Global Navigation Satellite System was compared with that computed using IRI-2016 along longitude 25° − 40oE. These were analyzed along with hemispheric changes in the neutral wind derived from the horizontal wind model and the TIMED GUVI columnar O/N2 data. IRI-2016 clearly captured the hemispheric asymmetry of the anomaly during all seasons albeit with some discrepancies in the magnitude and location of the crests. The winter anomaly in TEC which corresponded with greater O/N2 in the winter hemisphere was also predicted by IRI-2016 during December solstice. The model also captured the semiannual anomaly with stronger crests in the northern hemisphere. Furthermore, it reproduced the variation trend of the asymmetry index (A) in December solstice and equinox during noon. However, in June solstice the model failed to capture the winter anomaly and misrepresented the variation of A. This was linked with its inability to accurately predict the pattern of the neutral wind, the maximum height of the F2 layer and the changes in O/N2 in both hemispheres. The difference between the variations of EUV and F10.7 fluxes was also a potential source of errors in IRI-2016. The results highlight the significance of the inclusion of wind data in IRI-2016 in order to enhance its performance over East Africa.

Amaechi, Paul; Oyeyemi, Elijah; Akala, Andrew; Kaab, Mohamed; Younas, Waqar; Benkhaldoun, Zouhair; Khan, Majid; Mazaudier, Christine-Amory;

Published by: Advances in Space Research      Published on: aug

YEAR: 2021     DOI: 10.1016/j.asr.2021.03.040

Equatorial ionization anomaly; hemispheric asymmetry; IRI-2016; Semiannual anomaly; Winter anomaly

Hemispheric Asymmetries in the Mid-latitude Ionosphere During the September 7--8, 2017 Storm: Multi-instrument Observations

Hemispheric asymmetries of the Vertical Total Electron Content (VTEC) were observed during the first recovery phase of the geomagnetic storm on September 7–8, 2017. These asymmetries occurred at the mid latitudes at two different local times simultaneously: In the European-African sector (early morning), the storm time VTEC in the southern/northern hemisphere was higher/lower than the quiet time value, suggesting the southern/northern hemisphere entered the positive/negative phase (N−S+). In the East Asian-Australian sector (afternoon), the storm time VTEC change was positive in the northern hemisphere, but negative in the southern hemisphere (N+S−). The electron density profiles from digisondes demonstrated that the asymmetries appeared in the F region density as well. The plasma drifts data from digisondes, the column-integrated [O]/[N2] ratio from GUVI onboard the TIMED satellite, and the detrended VTEC were utilized to study the drivers of the asymmetries. Traveling Ionospheric Disturbance (TID) signatures were identified in the digisonde drift and detrended VTEC data before the appearance of the asymmetry. The magnitude of TIDs was larger in the hemisphere where the negative phase occurred later. The storm time [O]/[N2] ratio change was positive in Africa (S+) and negative in Europe (N−). However, the [O]/[N2] measurements were not available in the East Asian-Australian sector during the focused period. The hemispheric differences in the vertical drifts were also observed in both sectors. Therefore, the observed hemispheric asymmetries in both sectors are suggested to be due to the hemispheric asymmetries in the thermospheric composition change, vertical drift, and TID activity.

Wang, Zihan; Zou, Shasha; Liu, Lei; Ren, Jiaen; Aa, Ercha;

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

YEAR: 2021     DOI: 10.1029/2020JA028829

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

Local Time Dependant Hemispheric Asymmetry of the Ionosphere During the September 7-8 2017 Storm: Multi-Instrument Observations

Wang, Zihan; Zou, Shasha; Ren, Jiaen; Aa, Ercha; Liu, Lei;

Published by:       Published on:

YEAR: 2020     DOI:

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:

YEAR: 2020     DOI:

Analysis of the Impact of Long-Term Changes in the Geomagnetic Field on the Spatial Pattern of the Weddell Sea Anomaly

We simulated the impact of long‐term changes in the geomagnetic field on the spatial pattern of the Weddell Sea Anomaly (WSA). The Weddell Sea Anomaly, belonging to the region

Slominska, Ewa; Strumik, Marek; Slominski, Jan; Haagmans, Roger; Floberghagen, Rune;

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

YEAR: 2020     DOI: 10.1029/2019JA027528

North—south asymmetries in earth’s magnetic field

The solar-wind magnetosphere interaction primarily occurs at altitudes where the dipole component of Earth’s magnetic field is dominating. The disturbances that are created in this interaction propagate along magnetic field lines and interact with the ionosphere–thermosphere system. At ionospheric altitudes, the Earth’s field deviates significantly from a dipole. North–South asymmetries in the magnetic field imply that the magnetosphere–ionosphere–thermosphere (M–I–T) coupling is different in the two hemispheres. In this paper we review the primary differences in the magnetic field at polar latitudes, and the consequences that these have for the M–I–T coupling. We focus on two interhemispheric differences which are thought to have the strongest effects: 1) A difference in the offset between magnetic and geographic poles in the Northern and Southern Hemispheres, and 2) differences in the magnetic field strength at magnetically conjugate regions. These asymmetries lead to differences in plasma convection, neutral winds, total electron content, ion outflow, ionospheric currents and auroral precipitation.

Laundal, Karl; Cnossen, Ingrid; Milan, Stephen; Haaland, SE; Coxon, John; Pedatella, NM; Förster, Matthias; Reistad, Jone;

Published by: Space Science Reviews      Published on:

YEAR: 2017     DOI: 10.1007/s11214-016-0273-0

SSUSI-lite: next generation far-ultraviolet sensor for characterizing geospace

Paxton, Larry; Hicks, John; Grey, Matthew; Parker, Charles; Hourani, Ramsay; Marcotte, Kathryn; Carlsson, Uno; Kerem, Samuel; Osterman, Steven; Maas, Bryan; , others;

Published by:       Published on:

YEAR: 2016     DOI:

Solar illumination control of ionospheric outflow above polar cap arcs

We measure the flux density, composition, and energy of outflowing ions above the polar cap, accelerated by quasi-static electric fields parallel to the magnetic field and associated with polar cap arcs, using Cluster. Mapping the spacecraft position to its ionospheric foot point, we analyze the dependence of these parameters on the solar zenith angle (SZA). We find a clear transition at SZA between \~94\textdegree and \~107\textdegree, with the O⁺ flux higher above the sunlit ionosphere. This dependence on the illumination of the local ionosphere indicates that significant O⁺ upflow occurs locally above the polar ionosphere. The same is found for H⁺, but to a lesser extent. This effect can result in a seasonal variation of the total ion upflow from the polar ionosphere. Furthermore, we show that low-magnitude field-aligned potential drops are preferentially observed above the sunlit ionosphere, suggesting a feedback effect of ionospheric conductivity.

Maes, L.; Maggiolo, R.; De Keyser, J.; Dandouras, I.; Fear, R.; Fontaine, D.; Haaland, S.;

Published by: Geophysical Research Letters      Published on: 03/2015

YEAR: 2015     DOI: 10.1002/2014GL062972

cold ion outflow; ion upflow; polar cap arc; polar ionosphere; polar wind; solar illumination

Solar filament impact on 21 January 2005: Geospace consequences

On 21 January 2005, a moderate magnetic storm produced a number of anomalous features, some seen more typically during superstorms. The aim of this study is to establish the differences in the space environment from what we expect (and normally observe) for a storm of this intensity, which make it behave in some ways like a superstorm. The storm was driven by one of the fastest interplanetary coronal mass ejections in solar cycle 23, containing a piece of the dense erupting solar filament material. The momentum of the massive solar filament caused it to push its way through the flux rope as the interplanetary coronal mass ejection decelerated moving toward 1 AU creating the appearance of an eroded flux rope (see companion paper by Manchester et al. (2014)) and, in this case, limiting the intensity of the resulting geomagnetic storm. On impact, the solar filament further disrupted the partial ring current shielding in existence at the time, creating a brief superfountain in the equatorial ionosphere\textemdashan unusual occurrence for a moderate storm. Within 1 h after impact, a cold dense plasma sheet (CDPS) formed out of the filament material. As the interplanetary magnetic field (IMF) rotated from obliquely to more purely northward, the magnetotail transformed from an open to a closed configuration and the CDPS evolved from warmer to cooler temperatures. Plasma sheet densities reached tens per cubic centimeter along the flanks\textemdashhigh enough to inflate the magnetotail in the simulation under northward IMF conditions despite the cool temperatures. Observational evidence for this stretching was provided by a corresponding expansion and intensification of both the auroral oval and ring current precipitation zones linked to magnetotail stretching by field line curvature scattering. Strong Joule heating in the cusps, a by-product of the CDPS formation process, contributed to an equatorward neutral wind surge that reached low latitudes within 1\textendash2 h and intensified the equatorial ionization anomaly. Understanding the geospace consequences of extremes in density and pressure is important because some of the largest and most damaging space weather events ever observed contained similar intervals of dense solar material.

Kozyra, J.; Liemohn, M.; Cattell, C.; De Zeeuw, D.; Escoubet, C.; Evans, D.; Fang, X.; Fok, M.-C.; Frey, H.; Gonzalez, W.; Hairston, M.; Heelis, R.; Lu, G.; Manchester, W.; Mende, S.; Paxton, L.; Rastaetter, L.; Ridley, A.; Sandanger, M.; Soraas, F.; Sotirelis, T.; Thomsen, M.; Tsurutani, B.; Verkhoglyadova, O.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2014

YEAR: 2014     DOI: 10.1002/2013JA019748

cold dense plasma sheet; Equatorial anomaly; magnetotail; precipitation; prompt penetration electric field; solar filament

Improving Discoverability of Geophysical Data using Location Based Services

Morrison, Daniel; Barnes, Robin; Potter, Matthew; Nylund, Stuart; Patrone, Dennis; Weiss, Michele; Talaat, Elsayed; Sarris, Theodore; Smith, Daniel;

Published by:       Published on:

YEAR: 2014     DOI:

The quiet nighttime low-latitude ionosphere as observed by TIMED/GUVI

In this paper, we examine the nighttime ionosphere climatology structure in the low latitude region and discrepancies between Global Ultraviolet Imager (GUVI) observations and the IRI model predictions using (1) the magnetic zonal mean of electron number density as a function of altitude and magnetic latitude, (2) vertical electron density profiles at various levels of F10.7 index, (3) nighttime descent and magnitude decrease of the ionosphere, (4) point-to-point comparisons of F-peak height (hmF2) and density (NmF2), and (5) the magnetic longitudinal variations of hmF2 and NmF2. The data collected from the Thermosphere, Ionosphere, Mesosphere, Energetics, and Dynamics (TIMED) mission since its launch in December 2001 have provided great opportunities for many scientific investigations of the ionosphere. In this analysis, we investigate the climatology of the nighttime low-latitude ionosphere under low geomagnetic activity (kp\ ⩽\ 4) using the electron density profiles inferred from the airglow measurements obtained by the GUVI aboard the TIMED spacecraft and compared with the results obtained from IRI (International Reference Ionosphere) model-2001. The observed climatology is an essential tool for further understanding the electrodynamics in the low-latitude region and improving the model\textquoterights prediction capability. The time range of the GUVI data used in this study is from 2002 (day 053) to 2006 (day 304), and the IRI model predictions were produced at every GUVI location. The ionosphere observed is generally of greater density than what IRI predicts throughout the night for all four seasons for low and moderate solar activity while the model over-predicts the electron density near the F-region peak at high solar activity before midnight. Observations show that the height of the F-region peak has a steep descent from dusk to midnight and near midnight the height of layer is insensitive to solar conditions, significantly different than what is predicted by IRI. Longitudinal features shown in GUVI data are present in the low-latitude ionosphere after sunset and continue through to midnight after which the low-latitude ionosphere is largely zonally symmetric.

Talaat, E.R.; Yee, J.-H.; Hsieh, S.-Y.; Paxton, L.J.; DeMajistre, R.; Christensen, A.B.; Bilitza, D.;

Published by: Advances in Space Research      Published on: 02/2013

YEAR: 2013     DOI: 10.1016/j.asr.2012.11.012

Electron density; GUVI; Ionosphere; IRI; TIMED

Global propagation of gravity waves generated with the whole atmosphere transfer function model

Mayr, Hans; Talaat, Elsayed; Wolven, Brian;

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

YEAR: 2013     DOI:

VITMO: A Case Study in Virtual Observatories as Data Portals and Development of Web Services as Search Tools

Smith, D; Barnes, RJ; Morrison, D; Talaat, ER; Potter, M; Patrone, D; Weiss, M; Sarris, T;

Published by:       Published on:

YEAR: 2013     DOI:

An exploration of ionospheric and thermospheric properties and morphology during extreme solar minimum

During the sun s 11 year cycle, the thermosphere and ionosphere of the Earth react considerably to the changing levels of solar activity. It is commonly understood that as the solar

Haaser, Robert;

Published by:       Published on:

YEAR: 2012     DOI:

Propagation of plasma bubbles observed in Brazil from GPS and airglow data

Haase, J.S.; Dautermann, T.; Taylor, M.J.; Chapagain, N.; Calais, E.; Pautet, D.;

Published by: Advances in Space Research      Published on: Jan-05-2011

YEAR: 2011     DOI: 10.1016/j.asr.2010.09.025

The source of the longitudinal asymmetry in the ionospheric tidal structure

Kil, H.; Kwak, Y.-S.; Oh, S.-J.; Talaat, E.; Paxton, L.; Zhang, Y.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2011

YEAR: 2011     DOI: 10.1029/2011JA016781

Electrified MSTIDs at Low Latitudes

Miller, ES; Kil, H; Makela, JJ; Paxton, LJ; Talaat, ER;

Published by:       Published on:

YEAR: 2011     DOI:

A Dataset Conjunction Locator Service for the Virtual ITM Observatory and Other VxOs

Morrison, D; Barnes, RJ; Potter, M; Talaat, ER; Weiss, M;

Published by:       Published on:

YEAR: 2011     DOI:

Interhemispheric observations of emerging polar cap asymmetries

Laundal, K.; Ostgaard, N.; Snekvik, K.; Frey, H.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2010

YEAR: 2010     DOI: 10.1029/2009JA015160

Direct observations of nonmigrating diurnal tides in the equatorial thermosphere

Talaat, ER; Lieberman, RS;

Published by: Geophysical research letters      Published on:

YEAR: 2010     DOI:

LWS FST: Determine and Quantify the Responses of Atmospheric/Ionospheric Composition and Temperature to Solar XUV Spectral Variability and Energetic Particles

Talaat, Elsayed; Fuller-Rowell, Tim; Qian, Liying; Richards, Phil; Ridley, Aaron; Burns, Alan; Bernstein, Dennis; Chamberlin, Phillip; Fedrizzi, Mariangel; Hsieh, Syau-Yun; , others;

Published by: 38th COSPAR Scientific Assembly      Published on:

YEAR: 2010     DOI:

Night-side mid-latitude 135.6 nm intensity enhancements: TIMED/GUVI observations

Zhang, Y; Paxton, LJ; Talaat, ER; Kil, H;

Published by:       Published on:

YEAR: 2010     DOI:

Overview and summary of the Spread F Experiment (SpreadFEx)

We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx) performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI) and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian sector and included ground-based optical, radar, digisonde, and GPS measurements at a number of fixed and temporary sites. Related data on convection and plasma bubble structures were also collected by GOES 12, and the GUVI instrument aboard the TIMED satellite.\ 

Initial results of our SpreadFEx analyses are described separately by Fritts et al. (2009). Further analyses of these data provide additional evidence of 1) gravity wave (GW) activity near the mesopause apparently linked to deep convection predominantly to the west of our measurement sites, 2) small-scale GWs largely confined to lower altitudes, 3) larger-scale GWs apparently penetrating to much higher altitudes, 4) substantial GW amplitudes implied by digisonde electron densities, and 5) apparent influences of these perturbations in the lower F-region on the formation of equatorial spread F, RTI, and plasma bubbles extending to much higher altitudes. Other efforts with SpreadFEx data have also yielded 6) the occurrence, locations, and scales of deep convection, 7) the spatial and temporal evolutions of plasma bubbles, 8) 2-D (height-resolved) structures in electron density fluctuations and equatorial spread F at lower altitudes and plasma bubbles above, and 9) the occurrence of substantial tidal perturbations to the large-scale wind and temperature fields extending to bottomside F-layer and higher altitudes. Collectively, our various SpreadFEx analyses suggest direct links between deep tropical convection and large GW perturbations at large spatial scales at the bottomside F-layer and their likely contributions to the excitation of RTI and plasma bubbles extending to much higher altitudes.

Fritts, D.; Abdu, M.; Batista, B.; Batista, I.; Batista, P.; Buriti, R.; Clemesha, B.; Dautermann, T.; de Paula, E.; Fechine, B.; Fejer, B.; Gobbi, D.; Haase, J.; Kamalabadi, F.; Kherani, E.; Laughman, B.; Lima, P.; Liu, H.-L.; Medeiros, A.; Pautet, P.-D.; Riggin, D.; Rodrigues, F.; Sabbas, F.; Sobral, J.; Stamus, P.; Takahashi, H.; Taylor, M.; Vadas, S.; Vargas, F.; Wrasse, C.;

Published by: Annales Geophysicae      Published on: Jan-01-2009

YEAR: 2009     DOI: 10.5194/angeo-27-2141-2009

The Spread F Experiment (SpreadFEx): Program overview and first results

Fritts, D.; Abdu, M.; Batista, B.; Batista, I.; Batista, P.; Buriti, R.; Clemesha, B.; Dautermann, T.; de Paula, E.; Fechine, B.; Fejer, B.; Gobbi, D.; Haase, J.; Kamalabadi, F.; Kherani, E.; Laughman, B.; Lima, J.; Liu, H.-L.; Medeiros, A.; Pautet, P.-D.; Riggin, D.; Rodrigues, F.; Sabbas, Sao; Sobral, J.; Stamus, P.; Takahasi, H.; Taylor, M.; Vadas, S.; Vargas, F.; Wrasse, C.;

Published by: Earth Planets Space      Published on:

YEAR: 2009     DOI:

The causal link of the DE-3 tide, vertical drift, and plasma density

Kil, Hyosub; Talaat, Elsayed; Paxton, Larry; Fang, Tzu-Wei; Oh, Seung-Jun;

Published by:       Published on:

YEAR: 2009     DOI:

The effect of solar cycle on the coupling between the lower atmosphere and ionosphere

Talaat, ER;

Published by:       Published on:

YEAR: 2009     DOI:

SOLAR CYCLE EFFECTS ON THE COUPLING BETWEEN THE LOWER ATMOSPHERE AND IONOSPHERE

Talaat, ER;

Published by:       Published on:

YEAR: 2009     DOI:

Wave structures of the plasma density and vertical E$\times$ B drift in low-latitude F region

We investigate the seasonal, longitudinal, local time (LT), and altitudinal variations of the F region morphology at low latitudes using data from the first Republic of China satellite (ROCSAT-1), Global Ultraviolet Imager (GUVI), on board the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite, and the Defense Meteorological Satellite Program (DMSP) F13 and F15 satellites. Signatures of the longitudinally periodic plasma density structure emerge before 0900 LT. The wave structure is established before noon and further amplified in the afternoon. The amplitudes of the wave structure start to diminish in the evening. The wave-4 structure is clearly distinguishable during equinox and northern hemisphere summer. During northern hemisphere winter, the density structure can be characterized to either wave-4 or wave-3 structure owing to marginal separation of the two peaks in 180°–300°E. Observations of similar density structures from ROCSAT-1 (600 km) and DMSP (840 km) at 0930 and 1800 LT indicate the extension of the wave structure to altitudes greater than 840 km. The daytime wave structure persists into the night during the equinoxes but is significantly modified during the solstices. The modification is more significant at higher altitudes and is attributed to the effects of interhemispheric winds and the prereversal enhancement. The formation of the wavelike density structure in the morning and its temporal evolution in the afternoon show a close association with the vertical E × B drift. We conclude that the E × B drift during 0900–1200 LT determines the formation of the wavelike density structure.

Kil, H.; Talaat, E.; Oh, S.-J.; Paxton, L.; England, S.; Su, S.-Y.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2008

YEAR: 2008     DOI: 10.1029/2008JA013106

Equatorial ionosphere; wave structure; atmospheric tide

Lower Atmosphere Wave Effects on Ionospheric Variability

Talaat, Elsayed; Yee, Jeng-Hwa; Paxton, Larry; DeMajistre, Robert; Christensen, Andrew; Mlynczak, MG; , Russell; Zhu, Xun; Sotirelis, Thomas; Kil, Hyosub;

Published by: 37th COSPAR Scientific Assembly      Published on:

YEAR: 2008     DOI:

Wave structures of the plasma density and vertical E$\times$ B drift in low-latitude F region

Kil, H; Talaat, ER; Oh, S-J; Paxton, LJ; England, SL; Su, S-Y;

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

YEAR: 2008     DOI:

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

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

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

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

Overview of TIMED CEDAR observations showing the MLTI system response to changing drivers from solar maximum to solar minimum

Kozyra, JU; Crowley, G; Doe, RA; Mlynczak, MG; Paxton, LJ; Skinner, WR; Solomon, SC; Talaat, E; Woods, TN; Wu, Q; , others;

Published by:       Published on:

YEAR: 2007     DOI:

Longitudinal structure of the vertical E$\times$ B drift and ion density seen from ROCSAT-1

Kil, Hyosub; Oh, S-J; Kelley, MC; Paxton, LJ; England, SL; Talaat, E; Min, K-W; Su, S-Y;

Published by: Geophysical Research Letters      Published on:

YEAR: 2007     DOI:

The effect of the vertical ExB drift on the longitudinal plasma density structure in low-mid latitudes

Kil, H; Oh, S; Paxton, LJ; Talaat, E;

Published by:       Published on:

YEAR: 2007     DOI:

The Variabilities of the Mesosphere and Lower Thermosphere as observed by TIMED

Yee, J; Talaat, E; Zhu, X; Russell, J; Mlynczak, M; SKINNER, W; Paxton, L;

Published by:       Published on:

YEAR: 2007     DOI:

Inter-annual and long-term variations observed in the ITM system

Talaat, ER; Yee, J; Ruohoniemi, JM; Zhu, X; DeMajistre, R; Russell, J; Mlynczak, M; Paxton, L; Christensen, A;

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YEAR: 2007     DOI:

Global inventory of precipitating populations during the 15-30 January 2005 long-duration flares and magnetic storms: Relative efficacy at ozone destruction

Kozyra, JU; Cattell, CA; Clilverd, M; Evans, DS; Kavanagh, A; Liemohn, MW; Mende, SB; Paxton, LJ; Ridley, A; Soraas, F;

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YEAR: 2007     DOI:

The low-latitude ionosphere as observed by TIMED/GUVI and TOPEX/Jason and comparisons with the IRI model

Hsieh, SW; Talaat, ER; Bilitza, D; DeMajistre, R; Paxton, L; Christensen, A; Yee, J;

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YEAR: 2007     DOI:

VITMO: A Virtual Observatory for the ITM Community

Morrison, D; Weiss, M; Daley, R; Immer, L; Nylund, S; Yee, J; Talaat, E; Russell, J; Heelis, R; Kozyra, J; , others;

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YEAR: 2006     DOI:

Analyses of solar activity effects on the low-latitude ionosphere

Wolven, BC; Talaat, ER; Yee, J; DeMajistre, R; Paxton, LJ; Christensen, A; Sotirelis, T; Smith, DC; Bilitza, D; Azeem, I;

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YEAR: 2006     DOI:

The effects of solar activity on the low-latitude ionosphere as observed from space

Talaat, ER; Yee, J-H; DeMajistre, R; Paxton, LJ; Christensen, A; Sotirelis, T; Smith, DC; Bilitza, D;

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YEAR: 2006     DOI:

Geophysical Monograph SeriesRecurrent Magnetic Storms: Corotating Solar Wind StreamsResponse of the upper/middle atmosphere to coronal holes and powerful high-speed solar wind streams in 2003

Kozyra, J.; Crowley, G.; Emery, B.; Fang, X.; Maris, G.; Mlynczak, M.; Niciejewski, R.; Palo, S.; Paxton, L.; Randall, C.; Rong, P.-P.; Russell, J.; Skinner, W.; Solomon, S.; Talaat, E.; Wu, Q.; Yee, J.-H.;

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YEAR: 2006     DOI: 10.1029/GM16710.1029/167GM24

Lower Atmosphere Effects on Thermospheric and Ionospheric Variability

Talaat, ER; Yee, J; Paxton, L; DeMajistre, R; Christensen, A; Russell, J; Mlynczak, M; Zhu, X; Sotirelis, T; Smith, D;

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YEAR: 2006     DOI:

Developing cyber-infrastructure for addressing grand challenge questions in Sun-Earth system science: First results of a testbed worldwide online conference series

Kozyra, JU; Barnes, R; Fox, NJ; Fox, PA; Kuznetsova, MM; Morrison, D; Pallamraju, D; , Papitashvili; Ridley, A; Talaat, ER; , others;

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YEAR: 2006     DOI:

The climatology of the quiet nighttime low-latitude ionosphere

Talaat, ER; Yee, J; DeMajistre, R; Paxton, L; Kil, H; Zhang, Y; Sotirelis, T; Christensen, A; Palo, S; Azeem, I; , others;

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YEAR: 2005     DOI:

Simultaneous observations of the auroral ovals in both hemispheres under varying conditions

Stubbs, TJ; Vondrak, RR; Ostgaard, N; Sigwarth, JB; Frank, LA;

Published by: Geophysical research letters      Published on:

YEAR: 2005     DOI:

TIMED Contributions to the NASA Sun-Solar System Connections Great Observatory

Christensen, AB; Kozyra, J; Paxton, L; Talaat, E; Yee, J;

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YEAR: 2005     DOI: