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Found 20 entries in the Bibliography.
Showing entries from 1 through 20
| 2021 |
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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 solar activity; equatorial plasma bubble (EPB); GPS; Ionosphere; Plasma measurements; Plasmas; post-midnight; Southeast Asia; Time-frequency analysis |
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Latitudinal Dependence of Ionospheric Responses to Some Geomagnetic Storms during Low Solar Activity The Latitudinal dependence in the response of the Ionospheric F2-layer electron density (NmF2) and peak height (hmF2) to three geomagnetic storms of May and August 2010 has been examined. The data-sets used for the study were obtained from Ilorin, Nigeria (1.87° S/76.67° E), San Vito, Italy (34.68° N/90.38° E), Hermanus, South Africa (42.34° S/82.15° E), and Pruhonice, Czech Republic (45.66° N/90.38° E) geomagnetic coordinates. The quiet time result shows that the rise in NmF2 began earlier at San Vito, followed by P ... Joshua, B.; Adeniyi, J.; Olawepo, A.; Rabiu, Babatunde; Daniel, Okoh; Adebiyi, S.; Adebesin, B.; Ikubanni, S.; Abdurahim, B.; Published by: Geomagnetism and Aeronomy Published on: may YEAR: 2021 DOI: 10.1134/S0016793221030063 Electric field; Electron density; Geomagnetic storms; magnetosphere; peak height |
| 2017 |
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UV Airglow images from TIMED GUVI clearly showing the equatorial anomaly with embedded depletions that have penetrated through the F peak. Green, Red and Blue traces show the Spann, James; Swenson, Charles; Durao, Otavio; Loures, Luis; Heelis, Rod; Bishop, Rebecca; Le, Guan; Abdu, Mangalathayil; Krause, Linda; Fry, Craig; , others; Published by: Published on: |
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The scintillation prediction observations research task (sport) mission
Fry, G; Spann, James; Swenson, Charles; Durao, Otavio; Loures, Luis; Heelis, Rod; Bishop, Rebecca; Le, Guan; Abdu, Mangalathayli; Krause, Linda; , others; Published by: Published on: |
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Spann, James; Swenson, Charles; Dur\~ao, Otavio; Loures, Luis; Heelis, Rod; Bishop, Rebecca; Le, Guan; Abdu, Mangalathayil; Krause, Linda; Denardin, Clezio; , others; Published by: Published on: |
| 2016 |
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Electrodynamics of ionospheric weather over low latitudes The dynamic state of the ionosphere at low latitudes is largely controlled by electric fields originating from dynamo actions by atmospheric waves propagating from below and the solar wind-magnetosphere interaction from above. These electric fields cause structuring of the ionosphere in wide ranging spatial and temporal scales that impact on space-based communication and navigation systems constituting an important segment of our technology-based day-to-day lives. The largest of the ionosphere structures, the equatorial i ... Published by: Geoscience Letters Published on: 12/2016 YEAR: 2016 DOI: 10.1186/s40562-016-0043-6 |
| 2015 |
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Climatology of equatorial plasma bubble observed by MyRTKnet over the years 2008--2013 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.; Published by: Published on: 08/2015 YEAR: 2015 DOI: 10.1109/IconSpace.2015.7283752 |
| 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.; Published by: Journal of Geophysical Research: Space Physics Published on: 12/2014 YEAR: 2014 DOI: 10.1002/jgra.v119.1210.1002/2014JA020433 |
| 2013 |
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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 |
| 2012 |
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Equatorial ionospheric responses during two magnetic storms of moderate intensity are investigated, for the first time, by conjugate point observations in Brazil. The study focuses on storm-induced changes in the evening prereversal vertical drift, thermospheric trans-equatorial winds, spread F/plasma bubble irregularity development, electron density/plasma frequency heights, the EIA strength, and zonal plasma drifts. It is based on data obtained from five Digisondes operated in Brazil, three of them being part of a conju ... Abdu, M.; Batista, I.; Bertoni, F.; Reinisch, B.; Kherani, E.; Sobral, J.; Published by: Journal of Geophysical Research Published on: 05/2012 YEAR: 2012 DOI: 10.1029/2011JA017174 Equatorial ionosphere; Magnetic storms; plasma bubbles; plasma drifts; spread F; transequatorial winds |
| 2010 |
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Muella, M.; Kherani, E.; de Paula, E.; Cerruti, A.; Kintner, P.; Kantor, I.; Mitchell, C.; Batista, I.; Abdu, M.; Published by: Journal of Geophysical Research Published on: Jan-01-2010 YEAR: 2010 DOI: 10.1029/2009JA014788 |
| 2009 |
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The data from ground based experiments conducted during the 2005 SpreadFEx campaign in Brazil are used, with the help of theoretical model calculations, to investigate the precursor conditions, and especially, the role of gravity waves, in the instability initiation leading to equatorial spread F development. Data from a digisonde and a 30 MHz coherent back-scatter radar operated at an equatorial site, Sao Luis (dip angle: 2.7\textdegree) and from a digisonde operated at another equatorial site (dip angle: -11.5\textdegre ... Abdu, M.; Kherani, Alam; Batista, I.; de Paula, E.; Fritts, D.; Sobral, J.; Published by: Annales Geophysicae Published on: Jan-01-2009 YEAR: 2009 DOI: 10.5194/angeo-27-2607-2009 |
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Overview and summary of the Spread F Experiment (SpreadFEx) We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx) performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI) and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian ... Fritts, D.; Abdu, M.; Batista, B.; Batista, I.; Batista, P.; Buriti, R.; Clemesha, B.; Dautermann, T.; de Paula, E.; Fechine, B.; Fejer, B.; Gobbi, D.; Haase, J.; Kamalabadi, F.; Kherani, E.; Laughman, B.; Lima, P.; Liu, H.-L.; Medeiros, A.; Pautet, P.-D.; Riggin, D.; Rodrigues, F.; Sabbas, F.; Sobral, J.; Stamus, P.; Takahashi, H.; Taylor, M.; Vadas, S.; Vargas, F.; Wrasse, C.; Published by: Annales Geophysicae Published on: Jan-01-2009 YEAR: 2009 DOI: 10.5194/angeo-27-2141-2009 |
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Takahashi, H.; Taylor, M.; Pautet, P.-D.; Medeiros, A.; Gobbi, D.; Wrasse, C.; Fechine, J.; Abdu, M.; Batista, I.; Paula, E.; Sobral, J.; Arruda, D.; Vadas, S.; Sabbas, F.; Fritts, D.; Published by: Annales Geophysicae Published on: Jan-01-2009 YEAR: 2009 DOI: 10.5194/angeo-27-1477-2009 |
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The Spread F Experiment (SpreadFEx): Program overview and first results
Fritts, D.; Abdu, M.; Batista, B.; Batista, I.; Batista, P.; Buriti, R.; Clemesha, B.; Dautermann, T.; de Paula, E.; Fechine, B.; Fejer, B.; Gobbi, D.; Haase, J.; Kamalabadi, F.; Kherani, E.; Laughman, B.; Lima, J.; Liu, H.-L.; Medeiros, A.; Pautet, P.-D.; Riggin, D.; Rodrigues, F.; Sabbas, Sao; Sobral, J.; Stamus, P.; Takahasi, H.; Taylor, M.; Vadas, S.; Vargas, F.; Wrasse, C.; Published by: Earth Planets Space Published on: |
| 2008 |
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The Spread F Experiment, or SpreadFEx, was performed from September to November 2005 to define the potential role of neutral atmosphere dynamics, primarily gravity waves propagating upward from the lower atmosphere, in seeding equatorial spread F (ESF) and plasma bubbles extending to higher altitudes. A description of the SpreadFEx campaign motivations, goals, instrumentation, and structure, and an overview of the results presented in this special issue, are provided by Fritts et al. (2008a). The various analyses of neutr ... Fritts, D.; Vadas, S.; Riggin, D.; Abdu, M.; Batista, I.; Takahashi, H.; Medeiros, A.; Kamalabadi, F.; Liu, H.-L.; Fejer, B.; Taylor, M.; Published by: Annales Geophysicae Published on: 10/2008 YEAR: 2008 DOI: 10.5194/angeo-26-3235-2008 |
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F3 layer during penetration electric field The occurrence of an additional layer, called F3 layer, in the equatorial ionosphere at American, Indian, and Australian longitudes during the super double geomagnetic storm of 7–11 November 2004 is presented using observations and modeling. The observations show the occurrence, reoccurrence, and quick ascent to the topside ionosphere of unusually strong F3 layer in Australian longitude during the first super storm (8 November) and in Indian longitude during the second super storm (10 November), all with large reductions i ... Balan, N.; Thampi, S.; Lynn, K.; Otsuka, Y.; Alleyne, H.; Watanabe, S.; Abdu, M.; Fejer, B.; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2008 DOI: https://doi.org/10.1029/2008JA013206 |
| 2007 |
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During the SpreadFEx campaign from September 22 to November 8, 2005, two airglow CCD imagers, located at near Brasilia (14.8S, 47.6W, Mag. 10S) and at Cariri (7.4S, 36.5W, Mag. 9S) were operated simultaneously and measured the equatorial ionospheric bubble structures and their time evolution by monitoring the OI 6300 emission. From the 10 nights of coincident data, we observed that on some nights the bubbles was formed at the west of Cariri, but not seen from the Brasilia site. This suggests that the bubble formation and dev ... Takahashi*, H.; Pautet, P.-D.; Fechine, J.; Abdu, M.; Batista, I.; Paula, E.; Sobral, J.H.A.; Gobbi, D.; Arruda, D.; Batista, P.; Sabba, F.; Taylor, M.; Medeiros, A.; Buriti, R.; Wrasse, C.; Fritts, D.; Published by: Published on: YEAR: 2007 DOI: 10.1190/sbgf2007-404 |
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Robust speaker identification in noisy environment using cross diagonal GTF-ICA feature
Zhang, Yushi; Abdulla, Waleed; Published by: Published on: |
| 0 |
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"Gravity Wave Influences in the Thermosphere and Ionosphere: Observations and Recent Modeling" "Observational and theoretical studies have suggested gravity wave propagation and influences in the thermosphere and ionosphere for half a century. Gravity waves contribute, or are believed to contribute, to a variety of neutral and electrodynamic phenomena ranging from vertical coupling, energy and momentum transport and deposition, neutral perturbations and accelerations, traveling ionospheric disturbances, ionospheric irregularities, and plasma instabilities under quiet conditions to strong coupling from high to low lati ... Fritts, David; Abdu, Mangalathayil; Pancheva, Dora"; Published by: Published on: YEAR: 0 DOI: "10.1007/978-94-007-0326-1_8" |
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