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Found 665 entries in the Bibliography.
Showing entries from 201 through 250
| 2015 |
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Positive and negative ionospheric storms occurring during the 15 May 2005 geomagnetic superstorm This study focuses on the 15 May 2005 geomagnetic superstorm and aims to investigate the global variation of positive and negative storm phases and their development. Observations are provided by a series of global total electron content maps and multi-instrument line plots. Coupled Thermosphere-Ionosphere-Plasmasphere electrodynamics (CTIPe) simulations are also employed. Results reveal some sunward streaming plumes of storm-enhanced density (SED) over Asia and a well-developed midlatitude trough over North America formi ... Horvath, Ildiko; Lovell, Brian; YEAR: 2015 DOI: 10.1002/2015JA021206 CTIP/CTIPe simulations; Ionospheric storms; midlatitude trough; polar TOI; SED plume; thermospheric composition |
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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; YEAR: 2015 DOI: 10.1002/swe.v13.910.1002/2015SW001218 Geomagnetic storms; ionospheric storm effects; midlatitude ionosphere |
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Thermospheric mass density: A review The mass density of Earth\textquoterights thermosphere (\~90\textendash600\ km altitude) is a critical parameter for low Earth orbit prediction because of the atmospheric drag on satellites in this region. In this review, we first survey techniques for measuring thermospheric density, empirical models that provide a synthesis of historical data, and physical models that simulate the environment by solving fluid equations. We then review the climate and weather features that are observed in thermospheric density (incl ... YEAR: 2015 DOI: 10.1016/j.asr.2015.05.038 |
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Climatology of equatorial plasma bubble observed by MyRTKnet over the years 2008\textendash2013 Malaysia Real-Time Kinematics GNSS Network (MyRTKnet) which consists of 78 GPS receivers was used to investigate the occurrence of equatorial plasma bubble (EPB) along 96\textdegreeE-120\textdegreeE longitude. In this study, we present the monthly occurrence rate of EPB along the geographical longitudes of 96\textdegreeE-120\textdegreeE for a half of solar cycle period (2008-2013). A 2D map of rate of TEC change index (ROTI) projected at 300 km altitude was derived from the signal paths between GPS satellites and the rece ... Buhari, S.; Abdullah, M.; Yokoyama, T.; Hasbi, A.; Otsuka, Y.; Nishioka, M.; Bahari, S.A.; Tsugawa, T.; YEAR: 2015 DOI: 10.1109/IconSpace.2015.7283752 |
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We analyzed the G condition occurrence, using data of ionospheric vertical sounding from stations Norilsk (69.4\textdegreeN, 88.1\textdegreeЕ), Irkutsk (52.5\textdegreeN, 104\textdegreeЕ) and Hainan (18.3\textdegreeN, 109.3\textdegreeЕ) during the last extreme low solar activity period (2006\textendash2009). In most cases, the three stations registered the G condition in May\textendashAugust; in Norilsk, however, it was registered in March\textendashApril 2008. Under quiet geomagnetic conditions, the longest intervals ... N.M., Polekh; E.B., Romanova; K.G., Ratovsky; J.K., Shi; X., Wang; G.J., Wang; YEAR: 2015 DOI: 10.1016/j.jastp.2015.06.001 Vertical sounding; Ionogram; Critical frequency; G condition; Ionosphere\textendashatmosphere interaction |
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The effect of geomagnetic storms on low latitude ionosphere has been investigated with the help of Global Positioning System Total Electron Content (GPS-TEC) data. The investigation has been done with the aid of TEC data from the Indian equatorial region, Port Blair (PBR) and equatorial ionization anomaly region, Agartala (AGR). During the geomagnetic storms on 24th April and 15th July 2012, significant enhancement up to 150\% and depression up to 72\% in VTEC is observed in comparison to the normal day variation. The var ... Chakraborty, Monti; Kumar, Sanjay; De, Barin; Guha, Anirban; YEAR: 2015 DOI: 10.1007/s12040-015-0588-3 geomagnetic storm; Ionospheric total electron content; low latitude ionosphere |
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Explaining solar cycle effects on composition as it relates to the winter anomaly The solar cycle variation of\ F2\ region winter anomaly is related to solar cycle changes in the latitudinal winter-to-summer difference of O/N2. Here we use the National Center for Atmospheric Research\textendashGlobal Mean Model to develop a concept of why the latitudinal winter-to-summer difference of O/N2\ varies with solar cycle. The main driver for these seasonal changes in composition is vertical advection, which is expressed most simply in pressure coordinat ... Burns, A.; Solomon, S.; Wang, W.; Qian, L.; Zhang, Y.; Paxton, L.; Yue, X.; Thayer, J.; Liu, H.; YEAR: 2015 DOI: 10.1002/2015JA021220 |
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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; YEAR: 2015 DOI: 10.1016/j.jastp.2015.04.004 |
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Use of radio occultation to probe the high-latitude ionosphere We have explored the use of COSMIC data to provide valuable scientific information on the ionospheric impacts of energetic particle precipitation during geomagnetic storms. Ionospheric electron density in the E region, and hence ionospheric conductivity, is significantly altered by precipitating particles from the magnetosphere. This has global impacts on the thermosphere\textendashionosphere because of the important role of conductivity on high-latitude Joule heating. Two high-speed stream (HSS) and two coronal mass ejec ... Mannucci, A.; Tsurutani, B.; Verkhoglyadova, O.; Komjathy, A.; Pi, X.; YEAR: 2015 DOI: 10.5194/amt-8-2789-2015 |
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In this study, we investigate the ionospheric storm effects in the Chinese sector during 2 October 2013 geomagnetic storm. The TEC map over China sector (1\textdegree\ \texttimes\ 1\textdegree) and eight ionosondes data along the longitude of 110\textdegreeE are used to show significant positive ionospheric phases (enhancements in TEC and ionospheric peak electron density NmF2) in the high-middle latitude region and the negative effects at the low latitude and equatorial region during the storm. A wave structure ... Mao, Tian; Sun, Lingfeng; Hu, Lianhuan; Wang, Yungang; Wang, Zhijun; YEAR: 2015 DOI: 10.1016/j.asr.2015.05.045 |
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Characteristics of ionospheric north-south asymmetry and their relationship with irregularity Using the empirical ionospheric model, the flux-tube integrated electron density and the ratio between the F-region Pedersen conductivity and the total E- and F-region Pedersen conductivity are calculated to investigate the characteristics of the ionospheric asymmetry after sunset during a solar cycle. Furthermore, two indices representing the asymmetric strength of the parameters respectively are defined to study its relationship with the occurrences of the irregularities during different seasons and with different solar ... Luo, Weihua; Zhu, Zhengping; Lan, Jiaping; Li, Xuejing; YEAR: 2015 DOI: 10.1007/s11859-015-1088-7 asymmetry; Electron density; Ionosphere; irregularity; Pedersen conductivity |
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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.; YEAR: 2015 DOI: 10.1016/j.asr.2015.03.004 Ionospheric disturbance; Magnetic storm; X-ray flare; Solar cosmic rays; Coronal mass ejection |
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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.; YEAR: 2015 DOI: 10.1002/2015JA020993 Atmospheric tides; data assimilation; ionosphere/atmosphere interactions; sudden stratospheric warming |
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Thermospheric densities observed by Challenging Minisatellite Payload and Gravity Recovery and Climate Experiment satellites during 2002\textendash2010 and the globally averaged thermospheric densities from 1967 to 2007 have been used to investigate latitudinal, longitudinal, and height dependences of the multiday oscillations of thermospheric densities. The data show that the main multiday oscillations in thermospheric densities are 27, 13.5, 9, and 7 day oscillations. The high-correlation coefficients between the densit ... Xu, JiYao; Wang, Wenbin; Zhang, Shunrong; Liu, Xiao; Yuan, Wei; YEAR: 2015 DOI: 10.1002/2014JA020830 |
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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.; YEAR: 2015 DOI: 10.1002/2014JA020794 atmospheric gravity wave; incoherent scatter; solar terminator; traveling ionospheric disturbance |
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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.; . Y. Fu, S; Gou, X.; Cao, X.; Yao, Z.; Sun, W.; Wei, Y.; . Y. Pu, Z; YEAR: 2015 DOI: 10.1002/2014JA020912 magnetosphere-ionosphere coupling; transpolar arcs; in situ measurements |
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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; YEAR: 2015 DOI: 10.1007/s11430-014-5020-3 annual asymmetry of thermospheric mass density; solar EUV radiation; Sun-Earth distance |
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The International Reference Ionosphere \textendash Status 2013 This paper describes the latest version of the International Reference Ionosphere (IRI) model. IRI-2012 includes new models for the electron density and ion densities in the region below the F-peak, a storm-time model for the auroral E-region, an improved electron temperature model that includes variations with solar activity, and for the first time a description of auroral boundaries. In addition, the thermosphere model required for baseline neutral densities and temperatures was upgraded from MSIS-86 to the newer NRLMSI ... YEAR: 2015 DOI: 10.1016/j.asr.2014.07.032 |
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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 ... YEAR: 2015 DOI: 10.1002/2015JA021084 annual; eddy diffusion; neutral density; satellite drag; seasonal variability; semiannual |
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We analyze how the evening equatorial plasma vortex and the prereversal enhancement (PRE) of the vertical drift are influenced by the distributions of conductivity in the E and F regions in relation to the wind, through numerical simulations with the thermosphere-ionosphere-electrodynamics general circulation model coupled with the global ionosphere-plasmasphere model. The nightside electric potential satisfies an approximate minimization principle that unifies the connection of the horizontal and vertic ... YEAR: 2015 DOI: 10.1002/2014JA020935 equatorial ionosphere convection; night-time ionization; pre-reversal enhancement |
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On the equinoctial asymmetry in the threshold height for the occurrence of equatorial spread F In the present study, the threshold height (h Fc) for ESF occurrence irrespective of the polarity of the meridional winds during vernal and autumnal equinoxes is investigated using a large database spread over 1993\textendash2008. The characteristics of the thermosphere during the two equinoxes have also been examined using TIMED/GUVI O/N2 data. The major aspects that have emerged are (i) presence of significant equinoctial asymmetry inh Fc\ for the years examined, (ii) increas ... YEAR: 2015 DOI: 10.1016/j.jastp.2015.01.008 |
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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 ... Maes, L.; Maggiolo, R.; De Keyser, J.; Dandouras, I.; Fear, R.; Fontaine, D.; Haaland, S.; YEAR: 2015 DOI: 10.1002/2014GL062972 cold ion outflow; ion upflow; polar cap arc; polar ionosphere; polar wind; solar illumination |
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The Morphology of Equatorial Plasma Bubbles - a review Plasma bubbles that occur in the equatorial F-region make up one of the most distinguishing phenomena in the ionosphere. Bubbles represent plasma depletions with respect to the background ionosphere, and are the major source of electron density irregularities in the equatorial F-region. Such bubbles are seen as plasma depletion holes (in situ satellite observations), vertical plumes (radar observations), and emission-depletion bands elongated in the north-south direction (optical observations). However, no technique can o ... YEAR: 2015 DOI: 10.5140/JASS.2015.32.1.13 |
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The annual asymmetry in the F 2 layer during deep solar minimum (2008-2009): December anomaly Annual January/July midlatitude daytime asymmetry in monthly median NmF2 and model thermospheric parameters has been considered during deep solar minimum, (2008\textendash2009), when solar and geomagnetic activities were at the lowest level, to analyze the background effect due to the Sun-Earth minimum distance, perihelion, in the vicinity of the December solstice. Averaged over 10 midlatitude station pairs, the NmF2 asymmetry was found to be ≈1.23, while the ... YEAR: 2015 DOI: 10.1002/2014JA020929 midlatitude ionosphere; thermosphere composition and structure |
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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.; YEAR: 2015 DOI: 10.1002/2014JA020615 electron precipitation; global magnetosphere simulation; magnetosphere-ionosphere coupling |
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This paper presents an epoch analysis of global ionosphere responses to recurrent geomagnetic activity during 79 corotating interaction region (CIR) events from 2004 to 2009. The data used were GPS total electron content (TEC) data from the Madrigal Database at the Massachusetts Institute of Technology Haystack Observatory and the electron density (Ne) data obtained from CHAllenging Minisatellite Payload (CHAMP) observations. The results show that global ionosphere responses to CIR events have some common features. In hig ... Chen, Yanhong; Wang, Wenbin; Burns, Alan; Liu, Siqing; Gong, Jiancun; Yue, Xinan; Jiang, Guoying; Coster, Anthea; YEAR: 2015 DOI: 10.1002/2014JA020657 CIR events; epoch study; Ionospheric response; recurrent geomagnetic activity |
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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.; YEAR: 2015 DOI: 10.1002/2014JA020863 |
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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; YEAR: 2015 DOI: 10.1002/2014JA020552 |
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Far ultraviolet nighttime ionospheric photometer Far Ultraviolet Nighttime Ionopsheric Photometer (FNIP) is a newly-designed instrument for low earth orbit missions, observing the earth night airglow nadir at OI 135.6\ nm emission produced by ionospheric O++e recombination and receiving the horizontal information on nighttime ionosphere with a spatial resolution of about 1.6o\texttimes3.8o. This simple, highly robust instrument excludes OI 130.4 nm emission and Herzberg oxygen bands with lower power and approximately achieves a sensitivity of about 400\ counts ... Fu, Liping; Peng, Ruyi; Shi, Entao; Peng, Jilong; Wang, Tianfang; Jiang, Fang; Jia, Nan; Li, Xiaoyin; Wang, YongMei; YEAR: 2015 DOI: 10.1007/s10509-014-2139-9 F2 electron density distribution; FUV optical sensing remote; High sensitivity; Ionosphere; Payload |
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Longitudinal variations of the nighttime E layer electron density in the auroral zone Longitudinal variations of the nighttime E layer electron density (21:00\textendash03:00 magnetic local time) in the auroral zone are investigated, and their sources are discussed in terms of auroral precipitation and solar radiation. The electron density data used in this study are retrieved from Constellation Observing System for Meteorology, Ionosphere, and Climate radio occultation observations during 2006\textendash2009 under quiet geomagnetic activity (Kp <= 3) and solar minimum conditions. The mai ... Luan, Xiaoli; Wang, Wenbin; Dou, Xiankang; Burns, Alan; Yue, Xinan; YEAR: 2015 DOI: 10.1002/2014JA020610 auroral E layer; hemispheric asymmetry; longitudinal variations; Seasonal variations |
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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; YEAR: 2015 DOI: 10.1002/2014GL062355 |
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In the current work, temperature and wind data from the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite during the years 2002\textendash2007 were used to describe the seasonal variations of the westward propagating 6.5-day planetary wave in the mesosphere and lower thermosphere (MLT). Thermospheric composition data from the TIMED satellite and ionospheric total electron content (TEC) from the International Global Navigation Satellite System (GNSS) Service were then employed to carry out two ca ... Gan, Q.; Yue, J.; Chang, L.; Wang, W.; Zhang, S.; Du, J.; YEAR: 2015 DOI: 10.5194/angeo-33-913-2015 |
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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.; YEAR: 2015 DOI: 10.1002/2014EA000035 airglow and aurora; remote sensing; thermosphere: composition and chemistry; thermosphere: energy deposition |
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Research on the location of the auroral oval is important to understand the coupling processes of the Sun-Earth system. The equatorward boundary and poleward boundary of the auroral oval are significant parameters of the auroral oval location. Thus auroral oval boundary modeling is an efficient way to study the location of auroral oval. As the location of the auroral oval boundary is subject to a variety of geomagnetic factors, there are some limitations on traditional methods, which express the auroral oval boundary as a ... Han, Bing; Gao, Xinbo; Liu, Hui; Wang, Ping; YEAR: 2015 DOI: 10.1007/978-3-319-23862-310.1007/978-3-319-23862-3_10 |
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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; YEAR: 2015 DOI: 10.1117/12.2191701 |
| 2014 |
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High-density GPS receivers located in Southeast Asia (SEA) were utilized to study the two-dimensional structure of ionospheric plasma irregularities in the equatorial region. The longitudinal and latitudinal variations of tens of kilometer-scale irregularities associated with equatorial plasma bubbles (EPBs) were investigated using two-dimensional maps of the rate of total electron content change index (ROTI) from 127 GPS receivers with an average spacing of about 50\textendash100 km. The longitudinal variations of the tw ... Buhari, S.; Abdullah, M.; Hasbi, A.; Otsuka, Y.; Yokoyama, T.; Nishioka, M.; Tsugawa, T.; YEAR: 2014 DOI: 10.1002/jgra.v119.1210.1002/2014JA020433 |
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This paper investigates unusually deep and sudden electron density depletions (troughs) observed in the Poker Flat (Alaska) Incoherent Scatter Radar data in middle summer of 2007 and 2008. The troughs were observed in the premidnight sector during periods of weak magnetic and solar activity. The density recovered to normal levels around midnight. At the time when the electron density was undergoing its steep decrease, there was usually a surge of the order of 100 to 400 K in the ion temperature that lasted less than 1 h. ... Richards, P.; Nicolls, M.; St.-Maurice, J.-P.; Goodwin, L.; Ruohoniemi, J.; YEAR: 2014 DOI: 10.1002/jgra.v119.1210.1002/2014JA020541 |
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Local Geomagnetic Indices and the Prediction of Auroral Power The aurora has been related to magnetometer observations for centuries, and to geomagnetic indices for decades. As the number of stations and data processing power increases, just how auroral power (AP) relates to geomagnetic observations becomes a more tractable question. This paper compares Polar UVI AP observations during 1997 with a variety of indices. Local time (LT) versions of the SuperMAG auroral electrojet (SME) are introduced and examined, along with the corresponding upper and lower envelopes (SMU< ... YEAR: 2014 DOI: 10.1002/2014JA020524 AURORA; auroral electrojet; indices; Pedersen current; Prediction |
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A study of GPS ionospheric scintillations observed at Shenzhen Ionospheric scintillation variations are studied using GPS measurements at the low latitude station of Shenzhen (22.59\textdegreeN,\ 113.97\textdegreeE), situated under the northern crest of the equatorial anomaly region, from the Chinese Meridian Project. The results are presented for data collected during the current phase of rising solar activity (low to high solar activity) from December 2010 to April 2014. The results show that GPS scintillation events were largely a nighttime phenomenon during the whole observa ... Huang, Linfeng; Wang, Jinsong; Jiang, Yong; Chen, Zhou; Zhao, Kai; YEAR: 2014 DOI: 10.1016/j.asr.2014.08.023 |
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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.; YEAR: 2014 DOI: 10.1002/2014JD022423 |
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Spatial distribution of TEC across India in 2005: Seasonal asymmetries and IRI prediction Total electron content measured simultaneously at 10 locations over India during the low solar activity year 2005 is used to examine the temporal and spatial asymmetries and also to assess the predictability of the International Reference Ionosphere in respect of the observed asymmetrical distribution. The stations are distributed in latitude along 77\textdegreeE and in longitude along 23\textdegreeN forming a meridional and a zonal chain respectively. A longitudinal gradient positive towards east was observed in the dayt ... Hazarika, Rumajyoti; Bhuyan, Pradip; YEAR: 2014 DOI: 10.1016/j.asr.2014.07.011 Equatorial ionization anomaly; Ionosphere; IRI; solar activity; TEC |
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Transionospheric satellite navigation links operate primarily at L band and are frequently subject to severe degradation of performances arising out of ionospheric irregularities. Various characteristic features of equatorial ionospheric irregularity bubbles like the drift velocity, characteristic velocity, decorrelation time, and decorrelation distance can be determined using spaced aerial measurements at VHF. These parameters measured at VHF from a station Calcutta situated near the northern crest of the Equatorial Ioni ... YEAR: 2014 DOI: 10.1002/rds.v49.1010.1002/2014RS005406 GNSS position determination accuracy under adverse ionospheric conditions; GUVI; irregularity dynamics at VHF |
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Multiple instrumental observations including GPS total electron content (TEC), foF2 and hmF2 from ionosondes, vertical ion drift measurements from Communication/Navigation Outage Forecasting System, magnetometer data, and far ultraviolet airglow measured by Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics/Global Ultraviolet Imager (TIMED/GUVI) are used to investigate the profound ionospheric disturbances at midlatitude and low latitude during the 14 ... Liu, Jing; Liu, Libo; Nakamura, Takuji; Zhao, Biqiang; Ning, Baiqi; Yoshikawa, A.; YEAR: 2014 DOI: 10.1002/jgra.v119.910.1002/2014JA020273 GUVI; Ionospheric storm; prompt penetration electric fields; TIMED |
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A new data set of atomic oxygen abundance in the upper mesosphere and lower thermosphere is presented. The data are derived from the nighttime atomic oxygen green line limb emission measurements of the SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) instrument on the European Environmental Satellite. The temporal coverage is October 2002 until April 2012, and the latitudinal extent is 50\textdegreeS to 80\textdegreeN at 10 P.M. local time. This data set is compared to other satellite data ... Kaufmann, M.; Zhu, Y.; Ern, M.; Riese, M.; YEAR: 2014 DOI: 10.1002/grl.v41.1710.1002/2014GL060574 atomic oxygen; energy balance; mesopause; remote sensing data; SCIAMACHY |
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Recent investigation on the coupling between the ionosphere and upper atmosphere Scientific attention has recently been focused on the coupling of the earth\textquoterights upper atmosphere and ionosphere. In the present work, we review the advances in this field, emphasizing the studies and contributions of Chinese scholars. This work first introduces new developments in the observation instruments of the upper atmosphere. Two kinds of instruments are involved: optical instruments (lidars, FP interferometers and all-sky airglow imagers) and radio instruments (MST radars and all-sky meteor radars). Ba ... YEAR: 2014 DOI: 10.1007/s11430-014-4923-3 |
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\textquoterightSpace bubbles\textquoteright may have led to deadly battle in Afghanistan One of the deadliest battles of the U.S. war in Afghanistan may have been caused by plasma bubbles. That\textquoterights the conclusion of this unusual study, which finds that the turbulent pockets of ionized gas may have deflected U.S. military satellite radio signals enough to cause temporary communications blackouts in the region. Be sure to check out the amazing artwork. |
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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.; YEAR: 2014 DOI: 10.1002/2013JA019484 ionosphere total electron content; solar minimum; thermosphere mass density |
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his paper presents the model simulation results of ionospheric E-region parameters during geomagnetic storm on May 2\textendash3, 2010. For this investigation we used the Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP) developed in West Department of IZMIRAN. GSM TIP model simulations were performed using empirical model of high-energy electron precipitation. The temporal and spatial distributions of the lower ionosphere parameters and minor neutral species are presented. GSM TIP m ... Bessarab, F.S.; Korenkov, Yu.N.; Klimenko, V.V.; Klimenko, M.V.; Zhang, Y.; YEAR: 2014 DOI: 10.1016/j.asr.2014.08.003 E-region; Electric field; geomagnetic storm; Ionospheric modeling; IRI-2012; Nitric oxide density |
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Geomagnetic control of equatorial plasma bubble activity modeled by the TIEGCM with Kp Describing the day-to-day variability of Equatorial Plasma Bubble (EPB) occurrence remains a significant challenge. In this study we use the Thermosphere-Ionosphere Electrodynamics General Circulation Model (TIEGCM), driven by solar (F10.7) and geomagnetic (Kp) activity indices, to study daily variations of the linear Rayleigh-Taylor (R-T) instability growth rate in relation to the measured scintillation strength at five longitudinally distributed stations. For locations characterized ... Carter, B.; Retterer, J.; Yizengaw, E.; Groves, K.; Caton, R.; McNamara, L.; Bridgwood, C.; Francis, M.; Terkildsen, M.; Norman, R.; Zhang, K.; YEAR: 2014 DOI: 10.1002/2014GL060953 |
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GPS derived TEC and foF2 variability at an equatorial station and the performance of IRI-model The ionosphere induces a time delay in transionospheric radio signals such as the Global Positioning System (GPS) signal. The Total Electron Content (TEC) is a key parameter in the mitigation of ionospheric effects on transionospheric signals. The delay in GPS signal induced by the ionosphere is proportional to TEC along the path from the GPS satellite to a receiver. The diurnal monthly and seasonal variations of ionospheric electron content were studied during the year 2010, a year of extreme solar minimum (F10.7\ = ... Adebiyi, S.J.; Odeyemi, O.O.; Adimula, I.A.; Oladipo, O.A.; Ikubanni, S.O.; Adebesin, B.O.; Joshua, B.W.; YEAR: 2014 DOI: 10.1016/j.asr.2014.03.026 |
