GUVI Biblio





Notice:

  • Clicking on the title will open a new window with all details of the bibliographic entry.
  • Clicking on the DOI link will open a new window with the original bibliographic entry from the publisher.
  • Clicking on a single author will show all publications by the selected author.
  • Clicking on a single keyword, will show all publications by the selected keyword.



Found 233 entries in the Bibliography.


Showing entries from 51 through 100


2016

Midlatitude ionospheric changes to four great geomagnetic storms of solar cycle 23 in Southern and Northern Hemispheres

This paper presents an investigation of ionospheric response to great (Dst<=\textendash350 nT) geomagnetic storms that occurred during solar cycle 23. The storm periods analyzed are 29 March to 2 April 2001, 27\textendash31 October 2003, 18\textendash23 November 2003, and 6\textendash11 November 2004. Global Navigation Satellite System, total electron content (TEC), and ionosonde critical frequency of F 2 layer (f o F 2 ) data over Southern Hemisphere (African sector) and Northern Hemisphere (European sector) midlatitudes ...

Matamba, Tshimangadzo; Habarulema, John; a, Dalia;

Published by: Space Weather      Published on: 12/2016

YEAR: 2016     DOI: 10.1002/swe.v14.1210.1002/2016SW001516

Long-lasting negative ionospheric storm effects in low and middle latitudes during the recovery phase of the 17 March 2013 geomagnetic storm

In this paper, an ionospheric electron density reanalysis algorithm was used to generate global optimized electron density during the 17\textendash18 March 2013 geomagnetic storm by assimilating ~10 low Earth orbit satellites based and ~450 ground global navigation satellite system receiver-based total electron content into a background ionospheric model. The reanalyzed electron density could identify the large-scale ionospheric features quite well during storm time, including the storm-enhanced density, the positive iono ...

Yue, Xinan; Wang, Wenbin; Lei, Jiuhou; Burns, Alan; Zhang, Yongliang; Wan, Weixing; Liu, Libo; Hu, Lianhuan; Zhao, Biqiang; Schreiner, William;

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

YEAR: 2016     DOI: 10.1002/jgra.v121.910.1002/2016JA022984

Conjugate hemisphere ionospheric response to the St. Patrick\textquoterights Day storms of 2013 and 2015 in the 100\textdegreeE longitude sector

The effects of the St. Patrick\textquoterights Day geomagnetic storms of 2013 and 2015 in the equatorial and low-latitude regions of both hemispheres in the 100\textdegreeE longitude sector is investigated and compared with the response in the Indian sector at 77\textdegreeE. The data from a chain of ionosondes and GPS/Global Navigation Satellite Systems receivers at magnetic conjugate locations in the 100\textdegreeE sector have been used. The perturbation in the equatorial zonal electric field due to the prompt penetrat ...

Kalita, Bitap; Hazarika, Rumajyoti; Kakoti, Geetashree; Bhuyan, P.; Chakrabarty, D.; Seemala, G.; Wang, K.; Sharma, S.; Yokoyama, T.; Supnithi, P.; Komolmis, T.; Yatini, C; Le Huy, M.; Roy, P.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 10/2016

YEAR: 2016     DOI: 10.1002/2016JA023119

Ionospheric effects of magnetospheric and thermospheric disturbances on March 17\textendash19, 2015

Using vertical and oblique radio-sounding data, we analyze the ionospheric and thermospheric disturbances during the magnetic storm that occurred in northeastern Russia on March 17\textendash19, 2015. We consider the heliospheric sources that induced the magnetic storm. During the main and early recovery phases, the midlatitude stations are characterized by extremely low values of electron density at the F2 layer maximum. Using oblique sounding data, we recorded signals that propagated outside the great circle ar ...

Polekh, N.; Zolotukhina, N.; Romanova, E.; Ponomarchuk, S.; Kurkin, V.; Podlesnyi, A.;

Published by: Geomagnetism and Aeronomy      Published on: 09/2016

YEAR: 2016     DOI: 10.1134/S0016793216040174

Ionospheric effects of magnetospheric and thermospheric disturbances on March 17\textendash19, 2015

Using vertical and oblique radio-sounding data, we analyze the ionospheric and thermospheric disturbances during the magnetic storm that occurred in northeastern Russia on March 17\textendash19, 2015. We consider the heliospheric sources that induced the magnetic storm. During the main and early recovery phases, the midlatitude stations are characterized by extremely low values of electron density at the F2 layer maximum. Using oblique sounding data, we recorded signals that propagated outside the great circle ar ...

Polekh, N.; Zolotukhina, N.; Romanova, E.; Ponomarchuk, S.; Kurkin, V.; Podlesnyi, A.;

Published by: Geomagnetism and Aeronomy      Published on: 09/2016

YEAR: 2016     DOI: 10.1134/S0016793216040174

Long-term variations in the neutral gas composition of the thermosphere over Norilsk (2003\textendash2013)

Kushnarenko, Galina; Yakovleva, O.E.; Kuznetsova, G.M.;

Published by: Solnechno-Zemnaya Fizika      Published on: 08/2016

YEAR: 2016     DOI: 10.12737/issue_58e1a5fe7dc198.3567233310.12737/21465

Ionospheric data assimilation with thermosphere-ionosphere-electrodynamics general circulation model and GPS-TEC during geomagnetic storm conditions

The main purpose of this paper is to investigate the effects of rapid assimilation-forecast cycling on the performance of ionospheric data assimilation during geomagnetic storm conditions. An ensemble Kalman filter software developed by the National Center for Atmospheric Research (NCAR), called Data Assimilation Research Testbed, is applied to assimilate ground-based GPS total electron content (TEC) observations into a theoretical numerical model of the thermosphere and ionosphere (NCAR thermosphere-ionosphere-electrodyn ...

Chen, C.; Lin, C.; Matsuo, T.; Chen, W.; Lee, I.; Liu, J; Lin, J.; Hsu, C.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 05/2016

YEAR: 2016     DOI: 10.1002/2015JA021787

Long-duration depletion in the topside ionospheric total electron content during the recovery phase of the March 2015 strong storm

Topside ionospheric total electron content (TEC) observations from multiple low-Earth orbit (LEO) satellites have been used to investigate the local time, altitudinal, and longitudinal dependence of the topside ionospheric storm effect during both the main and recovery phases of the March 2015 geomagnetic storm. The results of this study show, for the first time, that there was a persistent topside TEC depletion that lasted for more than 3 days after the storm main phase at most longitudes, except in the Pacific Ocean reg ...

Zhong, Jiahao; Wang, Wenbin; Yue, Xinan; Burns, Alan; Dou, Xiankang; Lei, Jiuhou;

Published by: Journal of Geophysical Research: Space Physics      Published on: 04/2016

YEAR: 2016     DOI: 10.1002/2016JA022469

Middle- and low-latitude ionosphere response to 2015 St. Patrick\textquoterights Day geomagnetic storm

This paper presents a study of the St Patrick\textquoterights Day storm of 2015, with its ionospheric response at middle and low latitudes. The effects of the storm in each longitudinal sector (Asian, African, American, and Pacific) are characterized using global and regional electron content. At the beginning of the storm, one or two ionospheric positive storm effects are observed depending on the longitudinal zones. After the main phase of the storm, a strong decrease in ionization is observed at all longitudes, lasting ...

Nava, B.; iguez-Zuluaga, Rodr\; Alazo-Cuartas, K.; Kashcheyev, A.; e, Migoya-Oru\; Radicella, S.M.; Amory-Mazaudier, C.; Fleury, R.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 03/2016

YEAR: 2016     DOI: 10.1002/2015JA022299

Ionosphere-thermosphere (IT) response to solar wind forcing during magnetic storms

During magnetic storms, there is a strong response in the ionosphere and thermosphere which occurs at polar latitudes. Energy input in the form of Poynting flux and energetic particle precipitation, and energy output in the form of heated ions and neutrals have been detected at different altitudes and all local times. We have analyzed a number of storms, using satellite data from the Defense Meteorological Satellite Program (DMSP), the Gravity Recovery and Climate Experiment (GRACE), Gravity field and steady-state Ocean C ...

Huang, Cheryl; Huang, Yanshi; Su, Yi-Jiun; Sutton, Eric; Hairston, Marc; Coley, William;

Published by: Journal of Space Weather and Space Climate      Published on: 01/2016

YEAR: 2016     DOI: 10.1051/swsc/2015041

Energy distribution; Ionosphere; polar cap; solar wind; thermosphere

2015

Statistical analysis of the ionospheric response during geomagnetic storm conditions over South Africa using ionosonde and GPS data

This paper presents a statistical analysis of ionospheric response over ionosonde stations Grahamstown (33.3\textdegreeS, 26.5\textdegreeE, geographic) and Madimbo (22.4\textdegreeS, 30.9\textdegreeE, geographic), South Africa, during geomagnetic storm conditions which occurred during the period 1996\textendash2011. Such a climatological study is important in establishing local ionospheric behavior trend which later forms a basis for accurate modeling and forecasting electron density and critical frequency of the\ 

Matamba, Tshimangadzo; Habarulema, John; McKinnell, Lee-Anne;

Published by: Space Weather      Published on: 09/2015

YEAR: 2015     DOI: 10.1002/swe.v13.910.1002/2015SW001218

Geomagnetic storms; ionospheric storm effects; midlatitude ionosphere

Ionosphere equatorial ionization anomaly observed by GPS radio occultations during 2006\textendash2014

A large number of Global Position System (GPS) radio occultation (RO) observations have been accumulated in the University Corporation for Atmospheric Research (UCAR) Constellation Observation System for Meteorology, Ionosphere and Climate (COSMIC) Data Analysis and Archive Center (CDAAC) especially since the launch of COSMIC mission. This study made use of these RO data to study the morphology of ionosphere equatorial ionization anomaly (EIA) statistically during 2006\textendash2014. The ionospheric peak density (NmF2) a ...

Yue, Xinan; Schreiner, William; Kuo, Ying-Hwa; Lei, Jiuhou;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 07/2015

YEAR: 2015     DOI: 10.1016/j.jastp.2015.04.004

Ionospheric effects of solar flares and their associated particle ejections in March 2012

Flares of March 4\textendash9, 2012 were accompanied by an intensification of solar electromagnetic and corpuscular radiations and five coronal mass ejections. Bursts of X-rays and increased solar cosmic ray fluxes caused an increase in ionospheric absorption manifesting itself in data from vertical sounding stations as enhancements of the lowest frequency of reflections up to 4\textendash6\ MHz at the daytime and as the disappearance of reflections in the ionograms of high latitude stations. Interplanetary coronal m ...

Zolotukhina, N.; Polekh, N.; Kurkin, V.; Romanova, E.;

Published by: Advances in Space Research      Published on: 06/2015

YEAR: 2015     DOI: 10.1016/j.asr.2015.03.004

Ionospheric disturbance; Magnetic storm; X-ray flare; Solar cosmic rays; Coronal mass ejection

Global ionospheric response to the 2009 sudden stratospheric warming event using Ionospheric Data Assimilation Four-Dimensional (IDA4D) algorithm

A data assimilation algorithm is used to delineate the time-dependent three-dimensional ionospheric response to the 2009 sudden stratospheric warming (SSW) event. We use the Ionospheric Data Assimilation Four-Dimensional (IDA4D) algorithm to study the global ionospheric response to the 2009 SSW. This is the first study to utilize global ionospheric measurements in a data assimilation framework to unambiguously characterize atmosphere-ionosphere coupling via tidal modifications during the 2009 SSW event. Model results reve ...

Azeem, I.; Crowley, G.; Honniball, C.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 05/2015

YEAR: 2015     DOI: 10.1002/2015JA020993

Atmospheric tides; data assimilation; ionosphere/atmosphere interactions; sudden stratospheric warming

Radar observations of simultaneous traveling ionospheric disturbances and atmospheric gravity waves

Simultaneous observations of atmospheric gravity waves (AGWs) and traveling ionospheric disturbances (TIDs) measured by an incoherent scatter radar at high latitudes are shown. The measurements were made using a beam swing experiment of the EISCAT UHF radar. The\ F\ region TID is seen as wavefronts in electron density, whereas the\ E\ region AGW is seen in the oscillations of the neutral wind. The wave vector of the TID has a downward component indicating that energy propagates upward ...

en, Nygr\; Aikio, A.; Voiculescu, M.; Cai, L.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 05/2015

YEAR: 2015     DOI: 10.1002/2014JA020794

atmospheric gravity wave; incoherent scatter; solar terminator; traveling ionospheric disturbance

Transpolar arc observation after solar wind entry into the high-latitude magnetosphere

Recently, Cluster observations have revealed the presence of new regions of solar wind plasma entry at the high-latitude magnetospheric lobes tailward of the cusp region, mostly during periods of northward interplanetary magnetic field. In this study, observations from the Global Ultraviolet Imager (GUVI) experiment on board the TIMED spacecraft and Wideband Imaging Camera imager on board the IMAGE satellite are used to investigate a possible link between solar wind entry and the formation of transpolar arcs in the polar ...

Mailyan, B.; Shi, Q.; Kullen, A.; Maggiolo, R.; Zhang, Y.; Fear, R.; Zong, Q.-G.; Fu, S; Gou, X.; Cao, X.; Yao, Z.; Sun, W.; Wei, Y.; Pu, Z;

Published by: Journal of Geophysical Research: Space Physics      Published on: 05/2015

YEAR: 2015     DOI: 10.1002/2014JA020912

magnetosphere-ionosphere coupling; transpolar arcs; in situ measurements

Characteristics and mechanisms of the annual asymmetry of thermospheric mass density

In this paper, globally-averaged, thermospheric total mass density, derived from the orbits of \~5000 objects at 250, 400, and 550 km that were tracked from 1967 to 2006, has been used to quantitatively study the annual asymmetry of thermospheric mass density and its mechanism(s). The results show that thermospheric mass density had a significant annual asymmetry, which changed from year to year. The annual asymmetry at the three altitudes varied synchronously and its absolute value increased with altitudes. The results s ...

Ma, RuiPing; Xu, JiYao; Wang, Wenbin; Chen, GuangMing; Yuan, Wei; Lei, Jiuhou; Burns, Alan; Jiang, Guoying;

Published by: Science China Earth Sciences      Published on: 04/2015

YEAR: 2015     DOI: 10.1007/s11430-014-5020-3

annual asymmetry of thermospheric mass density; solar EUV radiation; Sun-Earth distance

Seasonal variability in global eddy diffusion and the effect on neutral density

We describe a method for making single-satellite estimates of the seasonal variability in global-average eddy diffusion coefficients. Eddy diffusion values as a function of time were estimated from residuals of neutral density measurements made by the Challenging Minisatellite Payload (CHAMP) and simulations made using the thermosphere-ionosphere-mesosphere electrodynamics global circulation model (TIME-GCM). The eddy diffusion coefficient results are quantitatively consistent with previous estimates based on satellite dr ...

Pilinski, M.; Crowley, G.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 04/2015

YEAR: 2015     DOI: 10.1002/2015JA021084

annual; eddy diffusion; neutral density; satellite drag; seasonal variability; semiannual

Electron precipitation models in global magnetosphere simulations

General methods for improving the specification of electron precipitation in global simulations are described and implemented in the Lyon-Fedder-Mobarry (LFM) global simulation model, and the quality of its predictions for precipitation is assessed. LFM\textquoterights existing diffuse and monoenergetic electron precipitation models are improved, and new models are developed for lower energy, broadband, and direct-entry cusp precipitation. The LFM simulation results for combined diffuse plus monoenergetic electron precipi ...

Zhang, B.; Lotko, W.; Brambles, O.; Wiltberger, M.; Lyon, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 02/2015

YEAR: 2015     DOI: 10.1002/2014JA020615

electron precipitation; global magnetosphere simulation; magnetosphere-ionosphere coupling

Link between pre-midnight second harmonic poloidal waves and auroral undulations: Conjugate observations with a Van Allen Probes spacecraft and a THEMIS all-sky imager

We report, for the first time, an auroral undulation event on 1 May 2013 observed by an all-sky imager (ASI) at Athabasca (L = 4.6), Canada, for which in situ field and particle measurements in the conjugate magnetosphere were available from a Van Allen Probes spacecraft. The ASI observed a train of auroral undulation structures emerging spontaneously in the pre-midnight subauroral ionosphere, during the growth phase of a substorm. The undulations had an azimuthal wavelength of ~180 km and propagated westward at ...

Motoba, T.; Takahashi, K.; Ukhorskiy, A.; Gkioulidou, M.; Mitchell, D.; Lanzerotti, L.; Korotova, G.; Donovan, E.; Wygant, J.; Kletzing, C.; Kurth, W.; Blake, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 02/2015

YEAR: 2015     DOI: 10.1002/2014JA020863

The long-duration positive storm effects in the equatorial ionosphere over Jicamarca

The long-duration positive storm (LPS) in the equatorial regions is relatively poorly understood. In this report, we conducted a statistical analysis of the LPS effects in the equatorial ionosphere over Jicamarca (12.0\textdegreeS, 283.2\textdegreeE) in 1998\textendash2010. There are 250 geomagnetic storms (minimum Dst \< -50 nT) in 1998\textendash2010, but the ionosonde observations at Jicamarca are available only for 204 storms. A total of 46 LPSs are identified in terms of the criterion that the storm time ...

Kuai, Jiawei; Liu, Libo; Liu, Jing; Zhao, Biqiang; Chen, Yiding; Le, Huijun; Wan, Weixing;

Published by: Journal of Geophysical Research: Space Physics      Published on: 02/2015

YEAR: 2015     DOI: 10.1002/2014JA020552

ionospheric long-duration positive storms

A new technique for remote sensing of O 2 density from 140 to 180 km

Observations of molecular oxygen are difficult to make in the Earth\textquoterights atmosphere between 140 and 200 km altitude. Perhaps the most accurate measurements to date have been obtained from satellite instruments that measure solar occultations of the limb. These do provide height-resolved O2 density measurements, but the nature of this technique is such that the temporal/spatial distribution of the measurements is uneven. Here a new space-based technique is described that utilizes two bright dayglow em ...

Hecht, James; Christensen, Andrew; Yee, Jeng-Hwa; Crowley, Geoff; Bishop, Rebeeca; Budzien, Scott; Stephan, Andrew; Evans, Scott;

Published by: Geophysical Research Letters      Published on: 01/2015

YEAR: 2015     DOI: 10.1002/2014GL062355

composition; technique; thermosphere

Remote Sensing of Earth\textquoterights Limb by TIMED/GUVI: Retrieval of thermospheric composition and temperature

The Global Ultraviolet Imager (GUVI) onboard the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite senses far ultraviolet emissions from O and N2 in the thermosphere. Transformation of far ultraviolet radiances measured on the Earth limb into O, N2, and O2 number densities and temperature quantifies these responses and demonstrates the value of simultaneous altitude and geographic information. Composition and temperature variations are available from 2002 to 2007 ...

Meier, R.; Picone, J.; Drob, D.; Bishop, J.; Emmert, J.; Lean, J.; Stephan, A.; Strickland, D.; Christensen, A.; Paxton, L.; Morrison, D.; Kil, H.; Wolven, B.; Woods, Thomas; Crowley, G.; Gibson, S.;

Published by: Earth and Space Science      Published on: 01/2015

YEAR: 2015     DOI: 10.1002/2014EA000035

airglow and aurora; remote sensing; thermosphere: composition and chemistry; thermosphere: energy deposition

Remote Sensing of Earth\textquoterights Limb by TIMED/GUVI: Retrieval of thermospheric composition and temperature

The Global Ultraviolet Imager (GUVI) onboard the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite senses far ultraviolet emissions from O and N2 in the thermosphere. Transformation of far ultraviolet radiances measured on the Earth limb into O, N2, and O2 number densities and temperature quantifies these responses and demonstrates the value of simultaneous altitude and geographic information. Composition and temperature variations are available from 2002 to 2007 ...

Meier, R.; Picone, J.; Drob, D.; Bishop, J.; Emmert, J.; Lean, J.; Stephan, A.; Strickland, D.; Christensen, A.; Paxton, L.; Morrison, D.; Kil, H.; Wolven, B.; Woods, Thomas; Crowley, G.; Gibson, S.;

Published by: Earth and Space Science      Published on: 01/2015

YEAR: 2015     DOI: 10.1002/2014EA000035

airglow and aurora; remote sensing; thermosphere: composition and chemistry; thermosphere: energy deposition

SPIE ProceedingsSSUSI-Lite: a far-ultraviolet hyper-spectral imager for space weather remote sensing

SSUSI-Lite is a far-ultraviolet (115-180nm) hyperspectral imager for monitoring space weather. The SSUSI and GUVI sensors, its predecessors, have demonstrated their value as space weather monitors. SSUSI-Lite is a refresh of the Special Sensor Ultraviolet Spectrographic Imager (SSUSI) design that has flown on the Defense Meteorological Satellite Program (DMSP) spacecraft F16 through F19. The refresh updates the 25-year-old design and insures that the next generation of SSUSI/GUVI sensors can be accommodated on any number ...

Ogorzalek, Bernard; Osterman, Steven; Carlsson, Uno; Grey, Matthew; Hicks, John; Hourani, Ramsey; Kerem, Samuel; Marcotte, Kathryn; Parker, Charles; Paxton, Larry;

Published by:       Published on:

YEAR: 2015     DOI: 10.1117/12.2191701

2014

Hemispheric distributions and interannual variability of NO y produced by energetic particle precipitation in 2002-2012

We investigate the interannual variability and hemispheric differences of reactive odd nitrogen produced by energetic particle precipitation (EPP-NOy) and transported into the stratosphere and lower mesosphere during polar winters in 2002\textendash2012. For this purpose, EPP-NOy amounts derived from observations of the Michelson Interferometer for Passive Atmospheric Sounding by means of a tracer correlation method have been used. Southern hemispheric (SH) seasonal maximum EPP-NO

Funke, B.; opez-Puertas, M.; Holt, L.; Randall, C.; Stiller, G.; von Clarmann, T.;

Published by: Journal of Geophysical Research: Atmospheres      Published on: 11/2014

YEAR: 2014     DOI: 10.1002/2014JD022423

Attribution of interminima changes in the global thermosphere and ionosphere

We present a statistical attribution analysis of the changes in global annual average thermospheric mass density and ionospheric total electron content (TEC) between the cycle 22/23 solar minimum (which occurred at epoch 1996.4) and the prolonged cycle 23/24 minimum (2008.8). The mass density data are derived from orbital drag, and the TEC data are derived from ground-based GPS receivers. The interminima change in mass density was -36\% relative to the 1996.4 yearly average. Considering each multiplicative forcing indepen ...

Emmert, J.; McDonald, S.; Drob, D.; Meier, R.; Lean, J.; Picone, J.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 08/2014

YEAR: 2014     DOI: 10.1002/2013JA019484

ionosphere total electron content; solar minimum; thermosphere mass density

Interplanetary magnetic field By control of prompt total electron content increases during superstorms

Large magnitude increases in ionospheric total electron content (TEC) that occur over 1\textendash3\ h on the dayside are a significant manifestation of the main phases of superstorms. For the largest superstorms of solar cycle 23 (based on the Dst index), ground networks of GPS receivers measured peak total electron content increases greater than a factor of 2 relative to quiet time TEC averaged over the broad latitude band \textpm40\textdegree for local times 1200\textendash1600\ LT. Near 30\textdegre ...

Mannucci, A.J.; Crowley, G.; Tsurutani, B.T.; Verkhoglyadova, O.P.; Komjathy, A.; Stephens, P.;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 08/2014

YEAR: 2014     DOI: 10.1016/j.jastp.2014.01.001

Geomagnetic storms; Ionosphere

The responses of ionospheric topside diffusive fluxes to two geomagnetic storms in October 2002

O+ field-aligned ambipolar diffusive velocities Vd and fluxes Фd in the topside ionosphere have been calculated from the observed profiles of electron density, ion, and electron temperatures during a 30 day incoherent scatter radar experiment conducted at Millstone Hill (288.5\textdegreeE, 42.6\textdegreeN) from 4 October to 4 November 2002. Two geomagnetic storms took place during this period. During the negative phases (depleted electron densities) of these two storms, ...

Chen, Guang-Ming; Xu, JiYao; Wang, Wenbin; Lei, Jiuhou; Zhang, Shun-Rong;

Published by: Journal of Geophysical Research: Space Physics      Published on: 08/2014

YEAR: 2014     DOI: 10.1002/2014JA020013

diffusion; geomagnetic storm; scale height; topside ionosphere

Seasonal trends of nighttime plasma density enhancements in the topside ionosphere

In situ registrations of electron density from the Langmuir probe on board Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions satellite are used to study spatial and temporal evolution of nighttime plasma density enhancements (NPDEs). The study introduces the normalized density difference index INDD in order to provide global estimates of the phenomenon. In the validation test, in situ data are compared with synthetic data set generated with the International Reference Ionosphe ...

Slominska, Ewa; Blecki, Jan; Lebreton, Jean-Pierre; Parrot, Michel; Slominski, Jan;

Published by: Journal of Geophysical Research: Space Physics      Published on: 08/2014

YEAR: 2014     DOI: 10.1002/2014JA020181

Electron density; Ionosphere; Langmuir probe; Weddell Sea Anomaly

Seasonal trends of nighttime plasma density enhancements in the topside ionosphere

In situ registrations of electron density from the Langmuir probe on board Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions satellite are used to study spatial and temporal evolution of nighttime plasma density enhancements (NPDEs). The study introduces the normalized density difference index INDD in order to provide global estimates of the phenomenon. In the validation test, in situ data are compared with synthetic data set generated with the International Reference Ionosphe ...

Slominska, Ewa; Blecki, Jan; Lebreton, Jean-Pierre; Parrot, Michel; Slominski, Jan;

Published by: Journal of Geophysical Research: Space Physics      Published on: 08/2014

YEAR: 2014     DOI: 10.1002/2014JA020181

Electron density; Ionosphere; Langmuir probe; Weddell Sea Anomaly

Simulations of the equatorial thermosphere anomaly: Geomagnetic activity modulation

The modulation of geomagnetic activity on the equatorial thermosphere anomaly (ETA) in thermospheric temperature under the high solar activity condition is investigated using the Thermosphere Ionosphere Electrodynamics General Circulation Model simulations. The model simulations during the geomagnetically disturbed interval, when the north-south component of the interplanetary magnetic field (Bz) oscillates between southward and northward directions, are analyzed and also compared with those under the ...

Lei, Jiuhou; Wang, Wenbin; Thayer, Jeffrey; Luan, Xiaoli; Dou, Xiankang; Burns, Alan; Solomon, Stanley;

Published by: Journal of Geophysical Research: Space Physics      Published on: 08/2014

YEAR: 2014     DOI: 10.1002/2014JA020152

equatorial thermosphere anomaly; geomagnetic activity; ion-neutral coupling; positive ionospheric storm

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 mas ...

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

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 mas ...

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

Responses of the lower thermospheric temperature to the 9 day and 13.5 day oscillations of recurrent geomagnetic activity

Responses of the lower thermospheric temperature to the 9 day and 13.5 day oscillations of recurrent geomagnetic activity and solar EUV radiation have been investigated using neutral temperature data observed by the TIMED/SABER (Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry) instrument and numerical experiments by the NCAR-TIME-GCM (National Center for Atmospheric Research\textendashthermosphere-ionosphere-mesosphere electrodynamics\textendashgene ...

Jiang, Guoying; Wang, Wenbin; Xu, JiYao; Yue, Jia; Burns, Alan; Lei, Jiuhou; Mlynczak, Martin; Rusell, James;

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

YEAR: 2014     DOI: 10.1002/jgra.v119.610.1002/2013JA019406

13.5 day variation; 9 day variation; Joule heating; lower thermospheric temperature; recurrent geomagnetic activity; solar EUV radiation

Strong ionospheric field-aligned currents for radial interplanetary magnetic fields

The present work has investigated the configuration of field-aligned currents (FACs) during a long period of radial interplanetary magnetic field (IMF) on 19 May 2002 by using high-resolution and precise vector magnetic field measurements of CHAMP satellite. During the interest period IMF By and Bz are weakly positive and Bx keeps pointing to the Earth for almost 10 h. The geomagnetic indices Dst is about -40 ...

Wang, Hui; Lühr, Hermann; Shue, Jih-Hong; Frey, Harald.; Kervalishvili, Guram; Huang, Tao; Cao, Xue; Pi, Gilbert; Ridley, Aaron;

Published by: Journal of Geophysical Research: Space Physics      Published on: 05/2014

YEAR: 2014     DOI: 10.1002/2014JA019951

air upwelling; field-aligned currents; radial interplanetary magnetic field

Traveling ionospheric disturbances observed at South African midlatitudes during the 29\textendash31 October 2003 geomagnetically disturbed period

This paper presents traveling ionospheric disturbances (TIDs) observations from GPS measurements over the South African region during the geomagnetically disturbed period of 29\textendash31 October 2003. Two receiver arrays, which were along two distinct longitudinal sectors of about 18\textdegree-20\textdegree and 27\textdegree-28\textdegree were used in order to investigate the amplitude, periods and virtual propagation characteristics of the storm induced ionospheric disturbances. The study revealed a large sudden TEC ...

Katamzi, Zama; Habarulema, John;

Published by: Advances in Space Research      Published on: 01/2014

YEAR: 2014     DOI: 10.1016/j.asr.2013.10.019

geomagnetic storm; Substorm; Total electron content (TEC); Traveling ionospheric disturbances (TIDs)

Earthquake Prediction Research Using Radio Tomography of the Ionosphere

Under development since its invention in 1990 as an ancillary application of ionospheric radio-tomography (RT), a new earthquake (EQ) prediction system is being evaluated. It has already been deployed along the United States West Coast, from Vancouver in Canada to San Diego in Southern California, and is currently undergoing Beta testing. This Chapter addresses RT\textendashEQ prediction concepts, the underlying RT theory, evolution and implementation, and a few examples of the Beta test system\textquoterights performance ...

Kunitsyn, Vyacheslav; Andreeva, Elena; Nesterov, Ivan; Padokhin, Artem; Gribkov, Dmitrii; Rekenthaler, Douglas;

Published by:       Published on:

YEAR: 2014     DOI: 10.1007/978-3-319-02207-9_15

Modelling ionospheric effects for L band GNSS receivers at high latitudes

The main objective of this study was to figure out a relationship between space weather environment phenomena (linked to solar and geomagnetic activity) and ionospheric events that impact L-band operating satellite systems (scintillations, electron content gradients), especially satellite navigation services, in the Nordic European area. A simple empirical model to forecast index of rate of change of the total electron content (ROTI) at high latitude has been developed associated with Kp geomagnetic prediction and the use ...

Boscher, D.; Carvalho, F.; Fabbro, V.; Lemorton, J.; Fleury, R.;

Published by:       Published on:

YEAR: 2014     DOI: 10.1109/EuCAP.2014.6902380

high latitude; Ionosphere; radiowave propagation; scintillation; solar and geomagnetic activity

Modelling ionospheric effects for L band GNSS receivers at high latitudes

The main objective of this study was to figure out a relationship between space weather environment phenomena (linked to solar and geomagnetic activity) and ionospheric events that impact L-band operating satellite systems (scintillations, electron content gradients), especially satellite navigation services, in the Nordic European area. A simple empirical model to forecast index of rate of change of the total electron content (ROTI) at high latitude has been developed associated with Kp geomagnetic prediction and the use ...

Boscher, D.; Carvalho, F.; Fabbro, V.; Lemorton, J.; Fleury, R.;

Published by:       Published on:

YEAR: 2014     DOI: 10.1109/EuCAP.2014.6902380

high latitude; Ionosphere; radiowave propagation; scintillation; solar and geomagnetic activity

2013

The effect of the 135.6 nm emission originated from the ionosphere on the TIMED/GUVI O/N 2 ratio

The column number density ratio of atomic oxygen to molecular nitrogen (O/N2\ ratio) provided by the Global Ultraviolet Imager (GUVI) onboard the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) satellite has been used as a diagnostic of the thermospheric neutral composition. However, a recent study claimed that the GUVI O/N2\ ratio is not a pure thermospheric parameter in low latitudes during periods of low geomagnetic activity. This study quantifies the O/N2 ...

Kil, H.; Lee, W.; Shim, J.; Paxton, L.J.; Zhang, Y.;

Published by: Journal of Geophysical Research: Space Physics      Published on: Jan-02-2013

YEAR: 2013     DOI: 10.1029/2012JA018112

The effect of geomagnetic-storm-induced enhancements to ionospheric emissions on the interpretation of the TIMED/GUVI O/N 2 ratio

[1]\ We examine the consequence of enhanced atomic oxygen (OI) 135.6 nm emissions due to the recombination of O+ with electrons on the column number density ratio of atomic oxygen to molecular nitrogen (O/N2 ratio) provided by Global Ultraviolet Imager (GUVI) on board the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics satellite. GUVI O/N2 ratio is derived from the measurements of OI 135.6 nm and N2 Lyman-Birge-Hopfield airglow emissions. The OI 135.6 nm emissi ...

Lee, Woo; Kil, Hyosub; Paxton, Larry; Zhang, Yongliang; Shim, Ja;

Published by: Journal of Geophysical Research: Space Physics      Published on: 12/2013

YEAR: 2013     DOI: 10.1002/2013JA019132

geomagnetic storm; GUVI O/N2 ratio; ionospheric effect

Estimating the propagation characteristics of large-scale traveling ionospheric disturbances using ground-based and satellite data

In this article, the propagation characteristics of large-scale traveling ionospheric disturbances (LS TIDs) are estimated during the geomagnetic storm periods of 14\textendash16 May 2005 and 25\textendash27 September 2011 over South Africa. One and two GPS arrays have been independently considered for the storms of 15 May 2005 and 26 September 2011, respectively. The average periods of dominant modes (≈ 2.5\textendash3.5h) in the time series data were determined by applying wavelet analysis on both ionosonde and GPS da ...

Habarulema, John; Katamzi, Zama; McKinnell, Lee-Anne;

Published by: Journal of Geophysical Research: Space Physics      Published on: 12/2013

YEAR: 2013     DOI: 10.1002/2013JA018997

characteristics of large scale TIDs; Geomagnetic storms; ionospheric irregularities

The Ionospheric Bubble Index deduced from magnetic field and plasma observations onboard Swarm

In the post-sunset tropical ionospheric F-region plasma density often exhibits depletions, which are usually called equatorial plasma bubbles (EPBs). In this paper we give an overview of the Swarm Level 2 Ionospheric Bubble Index (IBI), which is a standard scientific data of the Swarm mission. This product called L2-IBI is generated from magnetic field and plasma observations onboard Swarm, and gives information as to whether a Swarm magnetic field observation is affected by EPBs. We validate the performance of the L2-IBI ...

Park, J.; Noja, M.; Stolle, C.; Lühr, H.;

Published by: Earth, Planets and Space      Published on: 11/2014

YEAR: 2013     DOI: 10.5047/eps.2013.08.005

Equatorial ionosphere; Plasma irregularity; topside ionosphere

Equatorial ionization anomaly development as studied by GPS TEC and foF2 over Brazil: A comparison of observations with model results from SUPIM and IRI-2012

The equatorial ionization anomaly (EIA) development is studied using the total electron content (TEC) observed by the Global Positioning System (GPS) satellites, the F2-layer critical frequency (foF2) as measured by digisondes operated in the Brazilian sector, and by model simulation using the SUPIM (Sheffield University Plasmasphere Ionosphere Model). We have used two indices based on foF2 and TEC to represent the strength of the EIA Southern Anomaly Crest (SAC), which are denoted, respectively, by SAC( ...

Nogueira, P.A.B.; Abdu, M.A.; Souza, J.R.; Batista, I.S.; Bailey, G.J.; Santos, A.M.; Takahashi, H.;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 11/2013

YEAR: 2013     DOI: 10.1016/j.jastp.2013.08.013

Equatorial anomaly; foF2; Ionospheric modeling; TEC

Ion-neutral coupling during deep solar minimum

The equatorial ionosphere under conditions of deep solar minimum exhibits structuring due to tidal forces. Data from instruments carried by the Communication/Navigation Outage Forecasting System (C/NOFS) which was launched in April 2008 have been analyzed for the first 2 years following launch. The Planar Langmuir Probe (PLP), Ion Velocity Meter (IVM) and Vector Electric Field Investigation (VEFI) all detect periodic structures during the 2008\textendash2010 period which appear to be tides. However when the tidal features ...

Huang, Cheryl; Roddy, Patrick; Sutton, Eric; Stoneback, Russell; Pfaff, Robert; Gentile, Louise; Delay, Susan;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 10/2013

YEAR: 2013     DOI: 10.1016/j.jastp.2012.11.009

Equatorial ionosphere; Nonmigrating tides; Plasma depletions; thermosphere

A comparative study of TEC response for the African equatorial and mid-latitudes during storm conditions

The solar wind effects on the Earth\textquoterights environment are studied for their basic scientific values and crucial practical impacts on technological systems. This paper reports results of Total Electron Content (TEC) changes during two successive ionospheric storms of 7\textendash12 November 2004 using GPS data derived from dual frequency receivers located at African equatorial and midlatitudes. In the geographic coordinate system, equatorial TEC variability is considered over Libreville (0.36\textdegreeN, 9.67\te ...

Habarulema, John; McKinnell, Lee-Anne; a, Dalia; Zhang, Yongliang; Seemala, Gopi; Ngwira, Chigomezyo; Chum, Jaroslav; Opperman, Ben;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 09/2013

YEAR: 2013     DOI: 10.1016/j.jastp.2013.05.008

African equatorial and midlatitude TEC dynamics; Magnetic storms; TIDs

Are plasma bubbles a prerequisite for the formation of broad plasma depletions in the equatorial F region?

Formation of broad plasma depletions (BPDs) at night in the equatorial F region is understood in association with plasma bubbles. However, we report BPDs that do not show a connection with bubbles. The characteristics of BPDs are investigated using the observations of the Communication/Navigation Outage Forecasting System (C/NOFS) satellite on 31 December 2008, 28 July 2010, and 1 February 2011. On those days, BPDs are detected in the longitude regions where C/NOFS did not detect bubbles prior to the detection of ...

Kil, Hyosub; Lee, Woo;

Published by: Geophysical Research Letters      Published on: 07/2014

YEAR: 2013     DOI: 10.1002/grl.50693

bubbles; Equatorial ionosphere; irregularities

Is Space Weather Different Over Africa, and If So, Why? An AGU Chapman Conference Report

With the increasing reliance on technology, the impact of space weather on engineered systems will certainly increase unless suitable protective measures are taken. Understanding the physics behind space weather impacts and improving the forecasting are the major objectives of the space science community. It is well recognized that many space weather impacts, especially on communications systems, arise from structures in the ionosphere. The equatorial ionosphere, in particular, is one of the most complex and is host to nu ...

Yizengaw, Endawoke; Doherty, Patricia; Fuller-Rowell, Tim;

Published by: Space Weather      Published on: 07/2013

YEAR: 2013     DOI: 10.1002/swe.20063

atmosphere ionosphere interactions; ionospheric irregularities; space weather

Storm time spatial variations in TEC during moderate geomagnetic storms in extremely low solar activity conditions (2007\textendash2009) over Indian region

The total electron content (TEC) measurements from a network of GPS receivers were analyzed to investigate the storm time spatial response of ionosphere over the Indian longitude sector. The GPS receivers from the GPS Aided Geo Augmented Navigation (GAGAN) network which are uniquely located around the \~77\textdegreeE longitude are used in the present study so as to get the complete latitudinal coverage from the magnetic equator to low mid-latitude region. We have selected the most intense storms but of moderate intensity ...

Sunda, Surendra; Vyas, B.M.; Khekale, P.V.;

Published by: Advances in Space Research      Published on: 07/2013

YEAR: 2013     DOI: 10.1016/j.asr.2013.03.006

Electrodynamics; Equatorial and low-latitude; geomagnetic storm; Total electron content (TEC)



  1      2      3      4      5