GUVI

Global UltraViolet Imager

# GUVI Biblio

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## Found 70 entries in the Bibliography.

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 2022 Climatology of global, hemispheric and regional electron content variations during the solar cycles 23 and 24 We present the results of study on the variations of ionospheric total electron content (TEC) by using global, hemispheric, and regional electron contents computed from the global ionospheric maps (GIMs) for the period from 1999 to 2020. For a low and moderate solar activity, the global and regional electron contents vary linearly with solar 10.7 cm radio flux and EUV flux. While a saturation effect in the electron content verses EUV and F10.7 is found during the high solar activity periods at all regions, the maximum effec ... Younas, Waqar; Amory-Mazaudier, C.; Khan, Majid; Amaechi, Paul; Published by: Advances in Space Research      Published on: jul YEAR: 2022     DOI: 10.1016/j.asr.2022.07.029 Ionospheric response to the 26 August 2018 geomagnetic storm along 280° E and 316° E in the South American sector This paper studies the response of the ionospheric parameters critical frequency (foF2), their height (hmF2), and Total Electron Content (TEC) at mid, low, and near-equatorial latitudes of the South American sector during the intense geomagnetic storm of 26 August 2018. The ionospheric response at the beginning of the main phase was different depending on latitude (in general, there were decreases in foF2 at near-equatorial and low latitudes and small increases at mid-latitudes). During the recovery, positive storm effects i ... Mansilla, Gustavo; Zossi, Marta; Published by: Advances in Space Research      Published on: jan YEAR: 2022     DOI: 10.1016/j.asr.2021.08.002 Ionospheric Disturbances and Irregularities during the 25--26 August 2018 Geomagnetic Storm We use ground-based (GNSS, SuperDARN, and ionosondes) and space-borne (Swarm, CSES, and DMSP) instruments to study ionospheric disturbances due to the 25–26 August 2018 geomagnetic storm. The strongest large-scale storm-time enhancements were detected over the Asian and Pacific regions during the main and early recovery phases of the storm. In the American sector, there occurred the most complex effects caused by the action of multiple drivers. At the beginning of the storm, a large positive disturbance occurred over North ... Astafyeva, E.; Yasyukevich, Y.; Maletckii, B.; Oinats, A.; Vesnin, A.; Yasyukevich, A.; Syrovatskii, S.; Guendouz, N.; Published by: Journal of Geophysical Research: Space Physics      Published on: YEAR: 2022     DOI: 10.1029/2021JA029843 Correlations Between Giant Undulations and Plasmapause Configurations In this letter, we report the correlations between giant undulations (GUs) and plasmapause (PP) configurations based on GUs images and corresponding PP crossings of satellites between 2005 and 2019. Typically, GUs occur when the plasmasphere is eroded to form a thin and sharp PP during the storm main phase and early recovery phase. The thicknesses of the PP are usually comparable with the azimuthal wavelengths of the GUs and are smaller than the radial amplitudes of the GUs. The amplitudes and wavelengths are quasi-proporti ... Zhou, Yi-Jia; He, Fei; Yao, Zhong-Hua; Wei, Yong; Zhang, Xiao-Xin; Zhang, Yong-Liang; Published by: Geophysical Research Letters      Published on: YEAR: 2022     DOI: 10.1029/2022GL098627 The 15 January 2022 Hunga Tonga Eruption History as Inferred From Ionospheric Observations On 15 January 2022, the Hunga Tonga-Hunga Ha’apai submarine volcano erupted violently and triggered a giant atmospheric shock wave and tsunami. The exact mechanism of this extraordinary eruptive event, its size and magnitude are not well understood yet. In this work, we analyze data from the nearest ground-based receivers of Global Navigation Satellite System to explore the ionospheric total electron content (TEC) response to this event. We show that the ionospheric response consists of a giant TEC increase followed by a s ... Astafyeva, E.; Maletckii, B.; Mikesell, T.; Munaibari, E.; Ravanelli, M.; Coisson, P.; Manta, F.; Rolland, L.; Published by: Geophysical Research Letters      Published on: YEAR: 2022     DOI: 10.1029/2022GL098827 Properties of AKR-Like Emissions Recorded by the Low Altitude Satellite DEMETER During 6.5 Years Normally, auroral kilometric radiation (AKR) which is emitted in the auroral zones escapes from the Earth. But since a few decades very similar radiations are observed by ground-based receivers and by satellites at altitudes below the AKR generation area. They are called leaked AKR or AKR-like emissions because it is expected that there are linked to AKR. This paper deals with observations of such AKR-like emissions observed in the auroral zones (in the North and in the South) by the low-altitude satellite DEMETER. In total, ... Parrot, M.; Němec, F.; Santolík, O.; Published by: Journal of Geophysical Research: Space Physics      Published on: YEAR: 2022     DOI: 10.1029/2022JA030495 2021 The Influence of the Atmosphere on the Variability of the Electronic Concentration in the Ionosphere on January 2009 The results of the study of the variability of the electron concentration in the ionosphere in January 2009 are presented. Variations in the electron density in the ionosphere above individual stations and in the global electron content are considered based on the observation data and the results of the model calculations. Comparison of the ionospheric variability obtained from the results of calculations using the models of the upper atmosphere (GSM TIP) and the entire atmosphere (EAGLE) showed that the atmospheric-ionosphe ... Klimenko, M.; Ratovsky, K.; Klimenko, V.; Bessarab, F.; Sukhodolov, T.; Rozanov, E.; Published by: Russian Journal of Physical Chemistry B      Published on: sep YEAR: 2021     DOI: 10.1134/S1990793121050171 Seasonal Variation of Post-sunset and Post-midnight Equatorial Plasma Bubble in Malaysia during Moderate Solar Activity Level The equatorial plasma bubble (EPB) is a common event that occurred at the F-layer of the ionosphere due to plasma irregularities. Its occurrence can be observed around sunset and midnight hours, depending on the season. In this study, ROTI plot measurement was utilized in EPB detection, where the data was obtained from the Department of Survey and Mapping Malaysia (JUPEM). The seasonal variation of EPB in Langkawi, Malaysia was investigated for both post-sunset and post-midnight occurrence within the period of moderate solar ... Rosli, Nur; Hamid, Nurul; Abdullah, Mardina; Buhari, Suhaila; Sarudin, Idahwati; Published by:       Published on: nov YEAR: 2021     DOI: 10.1109/IconSpace53224.2021.9768743 Delay in Response of Global Electron Content and Electron Concentration at Various Altitudes to 27-Day Variations in Solar Activity We investigate the influence of 27-day variations in solar activity related to the rotation of the Sun around its axis on the thermosphere–ionosphere system at different latitudes and heights, using the results of the calculations of the model of the Earth’s upper atmosphere. Based on the results of the model calculations, related processes in the thermosphere–ionosphere system were analyzed in the period from June 20 to July 21, 2014. There is a clear reaction to the daytime electron concentration Ne in the ionosphere ... Klimenko, M.; Klimenko, V.; Ratovsky, K.; Yasyukevich, A.; Published by: Russian Journal of Physical Chemistry B      Published on: may YEAR: 2021     DOI: 10.1134/S1990793121030052 A ROTI-Aided Equatorial Plasma Bubbles Detection Method In this study, we present a Rate of Total Electron Content Index (ROTI)-aided equatorial plasma bubbles (EPBs) detection method based on a Global Navigation Satellite System (GNSS) ionospheric Total Electron Content (TEC). This technique seeks the EPBs occurrence time according to the ROTI values and then extracts the detrended ionospheric TEC series, which include EPBs signals using a low-order, partial polynomial fitting strategy. The EPBs over the Hong Kong area during the year of 2014 were detected using this technique. ... Tang, Long; Louis, Osei-Poku; Chen, Wu; Chen, Mingli; Published by: Remote Sensing      Published on: jan YEAR: 2021     DOI: 10.3390/rs13214356 Ionospheric response to solar and magnetospheric protons during January 15–22, 2005: EAGLE whole atmosphere model results We present an analysis of the ionosphere and thermosphere response to Solar Proton Events (SPE) and magnetospheric proton precipitation in January 2005, which was carried out using the model of the entire atmosphere EAGLE. The ionization rates for the considered period were acquired from the AIMOS (Atmospheric Ionization Module Osnabrück) dataset. For numerical experiments, we applied only the proton-induced ionization rates of that period, while all the other model input parameters, including the electron precipitations, c ... Bessarab, F.; Sukhodolov, T.; Klimenko, M.; Klimenko, V.; Korenkov, Yu.; Funke, B.; Zakharenkova, I.; Wissing, J.; Rozanov, E.; Published by: Advances in Space Research      Published on: jan YEAR: 2021     DOI: 10.1016/j.asr.2020.10.026 Responses of the African equatorial ionization anomaly (EIA) to some selected intense geomagnetic storms during the maximum phase of solar cycle 24 This study investigates the morphology of the GPS TEC responses in the African Equatorial Ionization Anomaly (EIA) region to intense geomagnetic storms during the ascending and maximum phases of solar cycle 24 (2012–2014). Specifically, eight intense geomagnetic storms with Dst ≤ −100 nT were considered in this investigation using TEC data obtained from 13 GNSS receivers in the East African region within 36–42°E geographic longitude; 29°N–10°S geographic latitude; ± 20°N magnetic latitude. The storm-time beh ... Oyedokun, O.; Akala, A.; Oyeyemi, E.; Published by: Advances in Space Research      Published on: feb YEAR: 2021     DOI: 10.1016/j.asr.2020.11.020 The Delayed Ionospheric Response to the 27-day Solar Rotation Period Analyzed With GOLD and IGS TEC Data The delayed ionospheric response is analyzed for two well-defined 27-day solar rotation periods in the year 2019 with solar radio flux index F10.7 and Global-scale Observations of the Limb and Disk (GOLD) data, like solar extreme ultraviolet (EUV) flux proxy, O/N2 column density ratio and peak electron density, as well as International Global Navigation Satellite System Service rapid high-rate total electron content (TEC) map data. Although the correlation between GOLD solar EUV flux proxy and TEC is similar to the correlati ... Schmölter, Erik; Berdermann, Jens; Codrescu, Mihail; Published by: Journal of Geophysical Research: Space Physics      Published on: YEAR: 2021     DOI: 10.1029/2020JA028861 A Comparative Study of Ionospheric Day-To-Day Variability Over Wuhan Based on Ionosonde Measurements and Model Simulations Ionospheric day-to-day variability is essential for understanding the space environment, while it is still challenging to properly quantify and forecast. In the present work, the day-to-day variability of F2 layer peak electron densities (NmF2) is examined from both observational and modeling perspectives. Ionosonde data over Wuhan station (30.5°N, 114.5°E; 19.3°N magnetic latitude) are compared with simulations from the specific dynamics Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension ... Zhou, Xu; Yue, Xinan; Liu, Han-Li; Lu, Xian; Wu, Haonan; Zhao, Xiukuan; He, Jianhui; Published by: Journal of Geophysical Research: Space Physics      Published on: YEAR: 2021     DOI: 10.1029/2020JA028589 First Comparison of Traveling Atmospheric Disturbances Observed in the Middle Thermosphere by Global-Scale Observations of the Limb and Disk to Traveling Ionospheric Disturbances Seen in Ground-Based Total Electron Content Observations Traveling ionospheric disturbances (TIDs) and their neutral counterparts known as traveling atmospheric disturbances (TADs) are believed to play a role in communicating inputs to other locations in the fluid. While these two phenomena are believed to be connected, they may not have a one-to-one correspondence as the geomagnetic field influences the TID but has no direct impact on the TAD. The relative amplitudes of the perturbations seen in the ionosphere and atmosphere have been observed but rarely together. This study repo ... England, Scott; Greer, Katelynn; Zhang, Shun-Rong; Evans, Scott; Solomon, Stanley; Eastes, Richard; McClintock, William; Burns, Alan; Published by: Journal of Geophysical Research: Space Physics      Published on: YEAR: 2021     DOI: 10.1029/2021JA029248 Low-Latitude Zonal Ion Drifts and Their Relationship With Subauroral Polarization Streams and Auroral Return Flows During Intense Magnetic Storms We analyze horizontal plasma drifts measured by the Defense Meteorological Satellite Program satellites during two intense magnetic storms. It is found, for the first time, that westward plasma flows associated with subauroral polarization streams (SAPS) in the dusk-evening sector penetrate continuously to equatorial latitudes. The westward ion drifts between subauroral and equatorial latitudes occur nearly simultaneously. The latitudinal profile of the westward ion drifts at low latitudes (approximately within ±30° magnet ... Huang, Chao-Song; Zhang, Yongliang; Wang, Wenbin; Lin, Dong; Wu, Qian; Published by: Journal of Geophysical Research: Space Physics      Published on: YEAR: 2021     DOI: 10.1029/2021JA030001 Plasma depletions lasting into daytime during the recovery phase of a geomagnetic storm in May 2017: Analysis and simulation of GPS total electron content observations This paper reports that plasma density depletions appearing at middle latitudes near sunrise survived until afternoon on 29 May 2017 during the recovery phase of a geomagnetic storm. By analyzing GPS data collected in Japan, we investigate temporal variations in the horizontal two-dimensional distribution of total electron content (TEC) during the geomagnetic storm. The SYM-H index reached −142 nT around 08 UT on 28 May 2017. TEC depletions extending up to approximately 38°N along the meridional direction appeared over Ja ... Otsuka, Yuichi; Shinbori, Atsuki; Sori, Takuya; Tsugawa, Takuya; Nishioka, Michi; Huba, Joseph; Published by: Earth and Planetary Physics      Published on: YEAR: 2021     DOI: 10.26464/epp2021046 Implication of Tidal Forcing Effects on the Zonal Variation of Solstice Equatorial Plasma Bubbles Equatorial plasma bubbles (EPBs) are plasma depletions that can occur in the nighttime ionospheric F region, causing scintillation in satellite navigation and communications signals. Past research has shown that EPB occurrence rates are higher during the equinoxes in most longitude zones. An exception is over the central Pacific and African sectors, where EPB activity has been found to maximize during solstice. Tsunoda et al. (2015) hypothesized that the solstice maxima in these two sectors could be driven by a zonal wavenum ... Chang, Loren; Salinas, Cornelius; Chiu, Yi-Chung; , Jones; Rajesh, P.; Chao, Chi-Kuang; Liu, Jann-Yenq; Lin, Charles; Hsiao, Tung-Yuan; Published by: Journal of Geophysical Research: Space Physics      Published on: YEAR: 2021     DOI: 10.1029/2020JA028295 Development and Validation of Precipitation Enhanced Densities for the Empirical Canadian High Arctic Ionospheric Model The Empirical Canadian High Artic Ionospheric Model (E-CHAIM) provides the four-dimensional ionosphere electron density at northern high latitudes (\textgreater50° geomagnetic latitude). Despite its emergence as the most reliable model for high-latitude ionosphere density, there remain significant deficiencies in E-CHAIM s representation of the lower ionosphere (below ∼200 km) due to a sparsity of reliable measurements at these altitudes, particularly during energetic particle precipitation events. To address this deficie ... Watson, C.; Themens, D.; Jayachandran, P.; Published by: Space Weather      Published on: YEAR: 2021     DOI: 10.1029/2021SW002779 2016 On the latitudinal changes in ionospheric electrodynamics and composition based on observations over the 76--77 E meridian from both hemispheres during a geomagnetic storm The relative contributions of the composition disturbances and the disturbance electric fields in the redistribution of ionospheric plasma is investigated in detail by taking the case of a long-duration positive ionospheric storm that occurred during 18\textendash21 February 2014. GPS total electron content (TEC) data from the Indian Antarctic station, Bharti (69.4\textdegreeS, 76.2\textdegreeE geographic), the northern midlatitude station Hanle (32.8\textdegreeN, 78.9\textdegreeE geographic), northern low-latitude statio ... Shreedevi, P.; Thampi, Smitha; Chakrabarty, D.; Choudhary, R.; Pant, Tarun; Bhardwaj, Anil; Mukherjee, S.; Published by: Journal of Geophysical Research: Space Physics      Published on: 02/2016 YEAR: 2016     DOI: 10.1002/2015JA021841 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 2015 The response of the ionosphere to intense geomagnetic storms in 2012 using GPS-TEC data from East Africa longitudinal sector The response of the ionosphere to intense magnetic storms has been studied using total electron content (TEC). TEC data recorded by a series of GPS receivers at a longitude\~35\textdegreeE\ covering a wide range of latitudes (32\textdegreeS\ to\ 68\textdegreeN, geographic) is analyzed to study spatio-temporal modifications of the vertical TEC (vTEC) during storms on 07 and 09 March 2012 and on 14 July 2012. We have observed main phase positive response at equatorial ionization anomaly (EIA) crests and mid l ... Tesema, F.; Damtie, B.; Nigussie, M.; Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 12/2015 YEAR: 2015     DOI: 10.1016/j.jastp.2015.10.021 The August 2011 URSI World Day campaign: Initial results During a 10-day URSI World Day observational campaign beginning on August 1, 2011, an isolated, major geomagnetic storm occurred. On August 5,\ Kp\ reached values of 8-and\ Dst\ dropped to -113\ nT. The occurrence of this isolated storm in the middle of a 10-day URSI World Day campaign provides and unprecedented opportunity to observe the coupling of solar wind energy into the magnetosphere and to evaluate the varied effects that occur in the coupled magnetosphere\text ... Immel, Thomas; Liu, Guiping; England, Scott; Goncharenko, Larisa; Erickson, Philip; Lyashenko, Mykhaylo; Milla, Marco; Chau, Jorge; Frey, Harald; Mende, Stephen; Zhou, Qihou; Stromme, Anja; Paxton, Larry; Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 11/2015 YEAR: 2015     DOI: 10.1016/j.jastp.2015.09.005 Ionospheric response to the 2015 St. Patrick's Day storm: A global multi-instrumental overview We present the first multi-instrumental results on the ionospheric response to the geomagnetic storm of 17\textendash18 March 2015 (the St. Patrick\textquoterights Day storm) that was up to now the strongest in the 24th solar cycle (minimum SYM-H value of -233 nT). The storm caused complex effects around the globe. The most dramatic positive ionospheric storm occurred at low latitudes in the morning (~100\textendash150\% enhancement) and postsunset (~80\textendash100\% enhancement) sectors. These significant vertical tota ... Astafyeva, Elvira; Zakharenkova, Irina; Förster, Matthias; Published by: Journal of Geophysical Research: Space Physics      Published on: 10/2015 YEAR: 2015     DOI: 10.1002/2015JA021629 Dynamics of the high-latitude ionospheric irregularities during the 17 March 2015 St. Patrick's Day storm: Ground-based GPS measurements We report first results on the study of the high-latitude ionospheric irregularities observed in worldwide GPS data during the St. Patrick\textquoterights Day geomagnetic storm (17 March 2015). Multisite GPS observations from more than 2500 ground-based GPS stations were used to analyze the dynamics of the ionospheric irregularities in the Northern and Southern Hemispheres. The most intense ionospheric irregularities lasted for more than 24 h starting at 07 UT of 17 March. This period correlates well with an increase of t ... Cherniak, Iurii; Zakharenkova, Irina; Redmon, Robert; Published by: Space Weather      Published on: 09/2015 YEAR: 2015     DOI: 10.1002/swe.v13.910.1002/2015SW001237 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; Published by: Wuhan University Journal of Natural Sciences      Published on: 06/2015 YEAR: 2015     DOI: 10.1007/s11859-015-1088-7 The international reference ionosphere--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 ... Bilitza, Dieter; Published by: Advances in Space Research      Published on: 04/2015 YEAR: 2015     DOI: 10.1016/j.asr.2014.07.032 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; Published by: Astrophysics and Space Science      Published on: 01/2015 YEAR: 2015     DOI: 10.1007/s10509-014-2139-9 2014 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; Published by: Advances in Space Research      Published on: 11/2014 YEAR: 2014     DOI: 10.1016/j.asr.2014.07.011 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 ... Wan, Weixing; Xu, JiYao; Published by: Science China Earth Sciences      Published on: 09/2014 YEAR: 2014     DOI: 10.1007/s11430-014-4923-3 Limb Viewing Hyper Spectral Imager (LiVHySI) for airglow measurements onboard YOUTHSAT-1 Bisht, R.S.; Hait, A.K.; Babu, P.N.; Sarkar, S.S.; Benerji, A.; Biswas, A.; Saji, A.K.; Samudraiah, D.R.M.; Kirankumar, A.S.; Pant, T.K.; Parimalarangan, T.; Published by: Advances in Space Research      Published on: 08/2014 YEAR: 2014     DOI: 10.1016/j.asr.2014.01.016 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 Ionospheric response to magnetic activity at low and mid-latitude stations The F2-layer response to the moderate storm of 5\textendash7 April 2010 was investigated using data from two equatorial stations (Ilorin: lat. 8.5\textdegreeN, 4.5\textdegreeE; Kwajalein: lat. 9\textdegreeN, long. 167.2\textdegreeE) and mid-latitude (San Vito: lat. 40.6\textdegreeN, long. 17.8\textdegreeE; Pruhonice: lat. 50\textdegreeN, long. 14.6\textdegreeE). Before storm commencement, enhancement, and depletion of NmF2 values were observed in the equatorial and mid-latitude stations, respectively, in ... Adebiyi, Shola; Adimula, Isaac; Oladipo, Olusola; Joshua, Benjamin; Adebesin, Babatunde; Ikubanni, Stephen; Published by: Acta Geophysica      Published on: 08/2014 YEAR: 2014     DOI: 10.2478/s11600-014-0205-x Ionospheric TEC, thermospheric cooling and $\Sigma$ [O/N2] compositional changes during the 6--17 March 2012 magnetic storm interval (CAWSES II) A series of four geomagnetic storms (the minimum SYM-H~-148\ nT) occurred during the March 6\textendash17, 2012 in the ascending phase of the solar cycle 24. This interval was selected by CAWSES II for its campaign. The GPS total electron content (TEC) database and JPL\textquoterights Global Ionospheric Maps (GIM) were used to study vertical TEC (VTEC) for different local times and latitude ranges. The largest response to geomagnetic activity is shown in increases of the low-latitude dayside VTEC. Several GPS sites f ... Verkhoglyadova, O.P.; Tsurutani, B.T.; Mannucci, A.J.; Mlynczak, M.G.; Hunt, L.A.; Paxton, L.J.; Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 08/2014 YEAR: 2014     DOI: 10.1016/j.jastp.2013.11.009 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 Quasi two day wave-related variability in the background dynamics and composition of the mesosphere/thermosphere and the ionosphere Dissipating planetary waves in the mesosphere/lower thermosphere (MLT) region may cause changes in the background dynamics of that region, subsequently driving variability throughout the broader thermosphere/ionosphere system via mixing due to the induced circulation changes. We report the results of case studies examining the possibility of such coupling during the northern winter in the context of the quasi two day wave (QTDW)\textemdasha planetary wave that recurrently grows to large amplitudes from the summer MLT duri ... Chang, Loren; Yue, Jia; Wang, Wenbin; Wu, Qian; Meier, R.; Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2014 YEAR: 2014     DOI: 10.1002/jgra.v119.610.1002/2014JA019936 On the solar cycle variation of the winter anomaly Constellation Observing System for Meteorology, Ionosphere and Climate, Ionosonde, and Global Ultraviolet Imager data have been used to investigate the solar cycle changes in the winter anomaly (the winter anomaly is defined as the enhancement of the F2 peak electron density in the winter hemisphere over that in the summer hemisphere) in the last solar cycle. There is no winter anomaly in solar minimum, and an enhancement of about 50\% in winter over summer ones on the same day of the year at solar max ... Burns, A.; Wang, W.; Qian, L.; Solomon, S.; Zhang, Y.; Paxton, L.; Yue, X.; Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2014 YEAR: 2014     DOI: 10.1002/jgra.v119.610.1002/2013JA019552 An analysis of the quiet time day-to-day variability in the formation of postsunset equatorial plasma bubbles in the Southeast Asian region Presented is an analysis of the occurrence of postsunset Equatorial Plasma Bubbles (EPBs) detected using a Global Positioning System (GPS) receiver at Vanimo. The three year data set shows that the EPB occurrence maximizes (minimizes) during the equinoxes (solstices), in good agreement with previous findings. The Vanimo ionosonde station is used with the GPS receiver in an analysis of the day-to-day EPB occurrence variability during the 2000 equinox period. A superposed epoch analysis (SEA) reveals that the altitude, and ... Carter, B.; Yizengaw, E.; Retterer, J.; Francis, M.; Terkildsen, M.; Marshall, R.; Norman, R.; Zhang, K.; Published by: Journal of Geophysical Research: Space Physics      Published on: 04/2014 YEAR: 2014     DOI: 10.1002/jgra.v119.410.1002/2013JA019570 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 2013 The anomalous ionosphere between solar cycles 23 and 24 The solar minimum period during 2008\textendash2009 was characterized by lower thermospheric density than the previous solar minimum and lower than any previously measured. Recent work used the NCAR Thermosphere-Ionosphere-Electrodynamics General Circulation Model to show that the primary cause of density changes from 1996 to 2008 was a small reduction in solar extreme ultraviolet (EUV) irradiance, causing a decrease in thermospheric temperature and hence a contracted thermosphere. There are similar effects in the ionosph ... Solomon, Stanley; Qian, Liying; Burns, Alan; Published by: Journal of Geophysical Research: Space Physics      Published on: 10/2013 YEAR: 2013     DOI: 10.1002/jgra.v118.1010.1002/jgra.50561 GPS TEC near the crest of the EIA at 95\textdegreeE during the ascending half of solar cycle 24 and comparison with IRI simulations Total electron content (TEC) data obtained from GPS dual frequency measurements during the ascending half of the solar cycle 24 from 2009 to 2012 over Dibrugarh (27.5\textdegreeN, 94.9\textdegreeE; 17.6\textdegreeN MLAT) have been used to study the diurnal, seasonal, annual and solar cycle variation of TEC. The measurements reported here are for the first time from the location situated at the poleward edge of the northern equatorial ionization anomaly (EIA) and within the peak region of the longitudinal wave number 4 (WN ... Bhuyan, Pradip; Hazarika, Rumajyoti; Published by: Advances in Space Research      Published on: 10/2013 YEAR: 2013     DOI: 10.1016/j.asr.2013.06.029 Ionospheric F-region response to geomagnetic disturbances The F2-region reaction to geomagnetic storms usually called as an ionospheric storm is a rather complicated event. It consists of so called positive and negative phases, which have very complicated spatial and temporal behavior. The main morphological features of ionospheric storms and the main processes governing their behavior were understood at the end of the 1900s and described in a series of review papers. During the recent decade there were many publications dedicated to the problem of ionospheric storms. In this pa ... Danilov, A.D.; Published by: Advances in Space Research      Published on: 08/2013 YEAR: 2013     DOI: 10.1016/j.asr.2013.04.019 Nightside midlatitude ionospheric arcs: TIMED/GUVI observations [1]\ Midlatitude arcs (MLA) are the phenomenon of the nightside enhancements of ionospheric electron density at 20\textdegree-45\textdegree magnetic latitudes in both hemispheres. We investigate the occurrence of MLA and its dependence on season using the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics/Global Ultraviolet Imager (TIMED/GUVI) O I 135.6 nm intensity data between March 2008 and March 2012. The 135.6 nm emission is mainly caused by radiant recombination between O+ ions and electron ... Zhang, Yongliang; Paxton, Larry; Kil, Hyosub; Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2013 YEAR: 2013     DOI: 10.1002/jgra.50327 Statistical analysis of an ionospheric parameter as a base for earthquake prediction This paper is related to the use of ionospheric density variations to tentatively predict earthquakes. The results of this statistical analysis are presented as a function of various parameters. The ion density was recorded by the low-altitude satellite DEMETER during more than 6 years, and a search for anomalies was automatically conducted with the complete data set. In a second time, a software checked if each anomaly could correspond to an earthquake. The search was conducted at less than 1500 km from the anomaly posit ... Li, Mei; Parrot, Michel; Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2013 YEAR: 2013     DOI: 10.1002/jgra.50313 The day-to-day longitudinal variability of the global ionospheric density distribution at low latitudes during low solar activity One important characteristic of longitudinal variability of the ionosphere is the global wavenumber-4 signature. Recent investigations have focused mainly on the climatological pattern during daytime and evening sectors. We investigate the day-to-day variability of the wavenumber-4 structure of the longitudinal ionospheric density distribution using the global total electron content (TEC) measurements from Global Positioning Systems receivers on the ground. The quiet time (Kp <= 3) day-to-day occurrence of the wavenumber- ... Pacheco, E.; Yizengaw, E.; Published by: Journal of Geophysical Research: Space Physics      Published on: 04/2013 YEAR: 2013     DOI: 10.1002/jgra.50241 Determination of the Ionospheric Electron Density Profile from FUV Remote Sensing Measurements A limb viewing model is established in this paper based on GUVI measurements of OI 135.6 nm nightglow and a method with Chapman function describing the distribution of ionospheric electron density is presented to obtain the ionospheric electron density profile. We apply the regularization and Newton iteration method to calculate ionospheric peak electron density and peak height with GUVI measurements, eliminating the ill condition of the weighted matrix. The ionospheric electron density profile is obtained using the calcu ... Jing, Wang; Yi, TANG; Zhi-Ge, ZHANG; Xu-Li, ZHENG; Guo-Qiang, NI; Published by: Chinese Journal of Geophysics      Published on: 03/2013 YEAR: 2013     DOI: 10.1002/cjg2.20011 Empirical STORM-E model: II. Geomagnetic corrections to nighttime ionospheric E-region electron densities Auroral nighttime infrared emission observed by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere\textendashIonosphere\textendashMesosphere Energetics and Dynamics (TIMED) satellite is used to develop an empirical model of geomagnetic storm enhancements to E-region electron densities. The empirical model is called STORM-E and will be incorporated into the 2012 release of the International Reference Ionosphere (IRI). The proxy for characterizing the E-region resp ... Mertens, Christopher; Xu, Xiaojing; Bilitza, Dieter; Mlynczak, Martin; Russell, James; Published by: Advances in Space Research      Published on: 02/2013 YEAR: 2013     DOI: 10.1016/j.asr.2012.09.014 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 ... 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 Nonmigrating tidal signatures in the magnitude and the inter-hemispheric asymmetry of the equatorial ionization anomaly Based on nine years of observations from the satellites CHAMP and GRACE the tidal signatures in the magnitude and the inter-hemisphere asymmetry of the equatorial ionization anomaly (EIA) have been investigated in this study. The EIA magnitude parameters show longitudinal wavenumber 4 and 3 (WN4/WN3) patterns during the months around August and December, respectively, while for different EIA parameters the contributions of the various tidal parameters are different. For the crest- to-trough ratio (CTR) the dominating nonm ... Xiong, C.; Lühr, H.; Published by: Annales Geophysicae      Published on: 01/2013 YEAR: 2013     DOI: 10.5194/angeo-31-1115-2013 Variability of ionospheric TEC during solar and geomagnetic minima (2008 and 2009): external high speed stream drivers We study solar wind\textendashionosphere coupling through the late declining phase/solar minimum and geomagnetic minimum phases during the last solar cycle (SC23) \textendash 2008 and 2009. This interval was characterized by sequences of high-speed solar wind streams (HSSs). The concomitant geomagnetic response was moderate geomagnetic storms and high-intensity, long-duration continuous auroral activity (HILDCAA) events. The JPL Global Ionospheric Map (GIM) software and the GPS total electron content (TEC) database were u ... Verkhoglyadova, O.; Tsurutani, B.; Mannucci, A.; Mlynczak, M.; Hunt, L.; Runge, T.; Published by: Annales Geophysicae      Published on: 01/2013 YEAR: 2013     DOI: 10.5194/angeo-31-263-2013

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