GUVI Biblio


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Found 665 entries in the Bibliography.

Showing entries from 151 through 200


Assessing ionospheric response during some strong storms in solar cycle 24 using various data sources

We present an analysis of a regional ionospheric response during six strong storms (-200\ nT\ <=Dst<=-100\ nT) that occurred in 2012 for the geographic latitudinal coverage of 10\textdegreeS\textendash40\textdegreeS within a longitude sector of 10\textdegreeE\textendash40\textdegreeE. Although these storms occurred during the same solar activity period and were all coronal mass ejection driven, their impacts and associated features on the ionosphere have been found different due t ...

Habarulema, John; Katamzi, Zama; Sibanda, Patrick; Matamba, Tshimangadzo;

YEAR: 2016     DOI: 10.1002/jgra.v122.110.1002/2016JA023066

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 ...

Abdu, Mangalathayil;

YEAR: 2016     DOI: 10.1186/s40562-016-0043-6

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

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

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

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

Non-thermal hydrogen atoms in the terrestrial upper thermosphere

Model predictions of the distribution and dynamical transport of hydrogen atoms in the terrestrial atmosphere have long-standing discrepancies with ultraviolet remote sensing measurements, indicating likely deficiencies in conventional theories regarding this crucial atmospheric constituent. Here we report the existence of non-thermal hydrogen atoms that are much hotter than the ambient oxygen atoms in the upper thermosphere. Analysis of satellite measurements indicates that the upper thermospheric hydrogen temperature, m ...

Qin, Jianqi; Waldrop, Lara;

YEAR: 2016     DOI: 10.1038/ncomms13655

Analysis of the global ionospheric disturbances of the March 2015 great storm

The global ionospheric storm in March 2015 was investigated by using data from over 3000 GPS stations worldwide. In this study, total electron content (TEC), rate of TEC (ROT), and ROT\textquoterights standard deviation rate of the TEC index, as well as the second-order difference operator TECT, were considered as main characteristic methods to distinguish ionosphereic disturbances. The results show that (1) based on the multiple methods above, we all observed that for the first time, there were three equatorward travelin ...

Yao, Yibin; Liu, Lei; Kong, Jian; Zhai, Changzhi;

YEAR: 2016     DOI: 10.1002/2016JA023352

Impacts of SABER CO 2 -based eddy diffusion coefficients in the lower thermosphere on the ionosphere/thermosphere

This work estimates global-mean Kzz using Sounding of the Atmosphere using Broadband Emission Radiometry/Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics monthly global-mean CO2 profiles and a one-dimensional transport model. It is then specified as a lower boundary into the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM). Results first show that global-mean CO2 in the mesosphere and lower thermosphere region has annual and semiannual oscillat ...

Salinas, Cornelius; Chang, Loren; Liang, Mao-Chang; Yue, Jia; Russell, James; Mlynczak, Martin;

YEAR: 2016     DOI: 10.1002/2016JA023161

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

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

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

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

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

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

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

YEAR: 2016     DOI: 10.1002/2016JA023119

Prompt penetration electric fields and the extreme topside ionospheric response to the June 22\textendash23, 2015 geomagnetic storm as seen by the Swarm constellation

Using data from the three Swarm satellites, we study the ionospheric response to the intense geomagnetic storm of June 22\textendash23, 2015. With the minimum SYM-H excursion of -207 nT, this storm is so far the second strongest geomagnetic storm in the current 24th solar cycle. A specific configuration of the Swarm satellites allowed investigation of the evolution of the storm-time ionospheric alterations on the day- and the nightside quasi-simultaneously. With the development of the main phase of the storm, a s ...

Astafyeva, Elvira; Zakharenkova, Irina; Alken, Patrick;

YEAR: 2016     DOI: 10.1186/s40623-016-0526-x

Variability and predictability of the space environment as related to lower atmosphere forcing

The Earth\textquoterights thermosphere and ionosphere (TI) are characterized by perpetual variability as integral parts of the atmosphere system, with intermittent disturbances from solar and geomagnetic forcing. This review examines how the TI variability is affected by processes originating from the lower atmosphere and implications for quantifying and forecasting the TI. This aspect of the TI variability has been increasingly appreciated in recent years from both observational and numerical studies, especially during t ...

Liu, H.-L.;

YEAR: 2016     DOI: 10.1002/2016SW001450

Direct observational evidence for disturbance dynamo on the daytime low-latitude ionosphere: A case study based on the 28 June 2013 space weather event

A case of the westward disturbance dynamo (DD) electric field, influencing the daytime equatorial and low-latitude ionosphere, during a geomagnetic storm that occurred on 28\textendash29 June 2013 is presented. The GPS total electron content (TEC) observations from a network of stations in the Indian equatorial, low and middle latitude regions along with the radio beacon TEC, ionosonde, and magnetic field observations are used to study the storm time behavior of the ionosphere. Negative ionospheric storm effects were seen ...

Thampi, Smitha; Shreedevi, P.; Choudhary, R.; Pant, Tarun; Chakrabarty, D.; Sunda, S.; Mukherjee, S.; Bhardwaj, Anil;

YEAR: 2016     DOI: 10.1002/2016JA023037

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

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

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

YEAR: 2016     DOI: 10.1134/S0016793216040174

Polar cap arcs: Sun-aligned or cusp-aligned?

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

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

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

The observation and simulation of ionospheric response to CIR/high-speed streams-induced geomagnetic activity on 4 April 2005

The ionospheric response to corotating interaction region (CIR)-induced geomagnetic activity on 4 April 2005 has been studied using in situ electron density measurements, ground GPS-total electron content (TEC) observations, and numerical simulations of the National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM). The case study resulted that the ionospheric positive response occurred from high to low latitudes. The positive effect at low latitudes could continue ...

Chen, Yanhong; Wang, Wenbin; Qiu, Na; Liu, Siqing; Gong, Jiancun; Huang, Wengeng;

YEAR: 2016     DOI: 10.1002/rds.v51.810.1002/2015RS005937

Peculiar features of the low-latitude and midlatitude ionospheric response to the St. Patrick\textquoterights Day geomagnetic storm of 17 March 2015

The current study aims at investigating and identifying the ionospheric effects of the geomagnetic storm that occurred during 17\textendash19 March 2015. Incidentally, with SYM-H hitting a minimum of -232\ nT, this was the strongest storm of the current solar cycle 24. The study investigates how the storm has affected the equatorial, low-latitude, and midlatitude ionosphere in the American and the European sectors using available ground-based ionosonde and GPS TEC (total electron content) data. The possible ...

Nayak, Chinmaya; Tsai, L.-C.; Su, S.-Y.; Galkin, I.; Tan, Adrian; Nofri, Ed; Jamjareegulgarn, Punyawi;

YEAR: 2016     DOI: 10.1002/2016JA022489

Solar wind driving of ionosphere-thermosphere responses in three storms near St. Patrick\textquoterights Day in 2012, 2013, and 2015

We identify interplanetary plasma regions associated with three intense interplanetary coronal mass ejections (ICMEs)-driven geomagnetic storm intervals which occurred around the same time of the year: day of year 74\textendash79 (March) of 2012, 2013, and 2015. We show that differences in solar wind drivers lead to different dynamical ionosphere-thermosphere (IT) responses and to different preconditioning of the IT system. We introduce a new hourly based global metric for average low-latitude and northern middle-latitude ...

Verkhoglyadova, O.; Tsurutani, B.; Mannucci, A.; Mlynczak, M.; Hunt, L.; Paxton, L.; Komjathy, A.;

YEAR: 2016     DOI: 10.1002/jgra.v121.910.1002/2016JA022883

Coherent seasonal, annual, and quasi-biennial variations in ionospheric tidal/SPW amplitudes

In this study, we examine the coherent spatial and temporal modes dominating the variation of selected ionospheric tidal and stationary planetary wave (SPW) signatures from 2007 to 2013 FORMOSAT-3/COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) total electron content observations using multidimensional ensemble empirical mode decomposition (MEEMD) from the Hilbert-Huang Transform. We examine the DW1, SW2, DE3, and SPW4 components, which are driven by a variety of in situ and vertical coupl ...

Chang, Loren; Sun, Yan-Yi; Yue, Jia; Wang, Jack; Chien, Shih-Han;

YEAR: 2016     DOI: 10.1002/2015JA022249

High-latitude energy input and its impact on the thermosphere

This paper presents a quantitative assessment of high-latitude energy input and its partitioning in the polar cap by synthesizing various space and ground-based observations during the 17 January 2005 geomagnetic storm. It was found that Joule heating is the primary form of magnetospheric energy input, especially during active times when the hemispheric-integrated Joule heating can be an order of magnitude larger than the hemispheric-integrated auroral power. Most of magnetospheric energy is dissipated in the auroral zone ...

Lu, G.; Richmond, A.; Lühr, H.; Paxton, L.;

YEAR: 2016     DOI: 10.1002/2015JA022294

High-latitude ionospheric irregularities: differences between ground- and space-based GPS measurements during the 2015 St. Patrick\textquoterights Day storm

We present an analysis of ionospheric irregularities at high latitudes during the 2015 St. Patrick\textquoterights Day storm. Our study used measurements from\ ~2700 ground-based GPS stations and GPS receivers onboard five low earth orbit (LEO) satellites\textemdashSwarm A, B and C, GRACE and TerraSAR-X\textemdashthat had close orbit altitudes of\ ~500\ km, and the Swarm in situ plasma densities. An analysis of the rate of TEC index (ROTI) derived from LEO\textendashGPS data, together with Swarm in situ pla ...

Cherniak, Iurii; Zakharenkova, Irina;

YEAR: 2016     DOI: 10.1186/s40623-016-0506-1

Equatorial ionospheric plasma drifts and O + concentration enhancements associated with disturbance dynamo during the 2015 St. Patrick\textquoterights Day magnetic storm

Disturbance dynamo is an important dynamic process during magnetic storms. However, very few direct observations of dynamo-induced plasma drifts and ion composition changes in the equatorial ionosphere are available. In this study, we use measurements of the Defense Meteorological Satellite Program (DMSP) satellites to identify the characteristics of the disturbance dynamo process in the topside equatorial ionosphere near dawn during the magnetic storm with a minimum Dst of -223 nT on 17 March 2015. Data from fou ...

Huang, Chao-Song; Wilson, Gordon; Hairston, Marc; Zhang, Yongliang; Wang, Wenbin; Liu, Jing;

YEAR: 2016     DOI: 10.1002/2016JA023072

Longitudinal variations of thermospheric composition at the solstices

O/N2, measured by the Global Ultraviolet Imager on board the Thermosphere Ionosphere Mesosphere Energetics Dynamics satellite, has large longitudinal variations at the solstices, which are simulated well in upper atmosphere general circulation models. These longitudinal variations are caused by the displacement of the Earth\textquoterights magnetic poles from the geographic ones. The location of a magnetic pole affects the latitude at which the winds, driven by heating in summer, converge in the subauroral regi ...

Qian, Liying; Burns, Alan; Wang, Wenbin; Solomon, Stanley; Zhang, Yongliang;

YEAR: 2016     DOI: 10.1002/2016JA022898

Modeling the problem of low-orbital satellite UV-tomography of the ionosphere

The results of modeling the direct and inverse problems of low-orbital satellite ultraviolet (UV) tomography of the ionospheric 135.6 OI volume emission rate are presented. The direct problem was solved with the orbital geometry of DMSP block 5D3 satellites with SSUSI and SSULI UV spectrographs among the other payloads, the real operating parameters of these instruments (the scan rate and the interval of scan angles), and the set of the model distributions of the volume emission rate that contain irregularities on various ...

Nesterov, I.; Padokhin, A.; Andreeva, E.; Kalashnikova, S.;

YEAR: 2016     DOI: 10.3103/S0027134916030103

Positive and negative GPS-TEC ionospheric storm effects during the extreme space weather event of March 2015 over the Brazilian sector

We studied the response of the ionosphere (F region) in the Brazilian sector during extreme space weather event of 17 March 2015 using a large network of 102 GPS- total electron content (TEC) stations. It is observed that the vertical total electron content (VTEC) was severely disturbed during the storm main and recovery phases. A wavelike oscillation with three peaks was observed in the TEC diurnal variation from equator to low latitudes during the storm main phase on 17\textendash18 March 2015. The latitudinal ...

Fagundes, P.; Cardoso, F.; Fejer, B.; Venkatesh, K.; Ribeiro, B.; Pillat, V.;

YEAR: 2016     DOI: 10.1002/2015JA022214

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

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

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

YEAR: 2016     DOI: 10.1002/2015JA021787

Solar cycle variations of thermospheric composition at the solstices

We examine the solar cycle variability of thermospheric composition (O/N2) at the solstices. Our observational and modeling studies show that the summer-to-winter latitudinal gradient of O/N2 is small at solar minimum but large at solar maximum; O/N2 is larger at solar maximum than at solar minimum on a global-mean basis; there is a seasonal asymmetry in the solar cycle variability of O/N2, with large solar cycle variations in the winter hemisphere and small solar cycle variatio ...

Qian, Liying; Burns, Alan; Solomon, Stanley; Wang, Wenbin; Zhang, Yongliang;

YEAR: 2016     DOI: 10.1002/2016JA022390

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

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

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

YEAR: 2016     DOI: 10.1002/2016JA022469

Thermospheric hydrogen response to increases in greenhouse gases

We investigated thermospheric hydrogen response to increase in greenhouse gases and the dependence of this response to solar activity, using a global mean version of the National Center for Atmospheric Research Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model. We separately doubled carbon dioxide (CO2) and methane (CH4) to study the influence of temperature and changes to source species for hydrogen. Our results indicate that both CO2 cooling and CH4 ...

Nossal, S.; Qian, L.; Solomon, S.; Burns, A.; Wang, W.;

YEAR: 2016     DOI: 10.1002/2015JA022008

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

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

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

YEAR: 2016     DOI: 10.1002/2015JA022299

Solar activity dependence of nightside aurora in winter conditions

The dependence of the nightside (21:00\textendash03:00 MLT; magnetic local time) auroral energy flux on solar activity was quantitatively studied for winter/dark and geomagnetically quiet conditions. Using data combined from Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics/Global Ultraviolet Imager and Defense Meteorological Satellite Program/Special Sensor Ultraviolet Spectrographic Imager observations, we separated the effects of geomagnetic activity from those of solar flux on the nightside auroral precipit ...

Zhou, Su; Luan, Xiaoli; Dou, Xiankang;

YEAR: 2016     DOI: 10.1002/2015JA021865

auroral conjugate effects; auroral geomagnetic activity variation; auroral imaging scaling; auroral solar cycle variation

Effects of the Equatorial Ionosphere Anomaly on the Inter-Hemispheric Circulation in the Thermosphere

We investigate the interhemispheric circulation at the solstices, in order to understand why O/N2\ is larger in the northern hemisphere winter than in the southern hemisphere winter. Our studies reveal that the equatorial ionosphere anomaly (EIA) significantly impacts the summer-to-winter wind through plasma-neutral collisional heating, which changes the summer-to-winter pressure gradient, and ion drag. Consequently, the wind is suppressed in the summer hemisphere as it encounters the EIA but accelerates a ...

Qian, Liying; Burns, Alan; Wang, Wenbin; Solomon, Stanley; Zhang, Yongliang; Hsu, V.;

YEAR: 2016     DOI: 10.1002/2015JA022169

Equatorial ionization anomaly; interhemispheric circulation; ionosphere winter anomaly; plasma-neutral collisional heating; thermosphere composition; vertical advection

Ionospheric F2 layer responses to total solar eclipses at low and mid-latitude

In this article, we presented ionospheric F2 responses to total solar eclipses on the basis of the data obtained from five (5) equatorial/low-latitude and twenty-seven (27) mid-latitude ionosonde stations, which are within the obscuration percentage of 50\textendash100\% of the path of the total solar eclipses progression. Statistically, the diurnal changes in the F2 layer peak height hmF2 and electron density NmF2, as well as the latitudinal and hemispheric dependence and the contribution of both magnetic and solar activ ...

Adekoya, B.J.; Chukwuma, V.U.;

YEAR: 2016     DOI: 10.1016/j.jastp.2016.01.006

Equatorial/low-latitude; Hemisphere; mid-latitude; NmF2 and hmF2; Solar ionizing radiation

On the latitudinal changes in ionospheric electrodynamics and composition based on observations over the 76-77\textdegreeE 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.;

YEAR: 2016     DOI: 10.1002/2015JA021841

Geomagnetic storms; High latitude low latitude coupling; Ionosphere; positive ionospheric storm

Universal time variations of the auroral hemispheric power and their interhemispheric asymmetry from TIMED/GUVI observations

This paper quantitatively analyzes the auroral hemispheric power (HP) and its interhemispheric asymmetry as a function of universal time (UT) for geomagnetically quiet conditions (Kp 1\textendash3) from Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Global Ultraviolet Imager (TIMED/GUVI) imaging observations. The HP variation with UT can be approximately characterized as two cases: One is for similar HP variations in the equinoxes in the Northern Hemisphere and for the June solstices of both hemispher ...

Luan, Xiaoli; Wang, Wenbin; Burns, Alan; Dou, Xiankang;

YEAR: 2016     DOI: 10.1002/2016JA022730

Average field-aligned current configuration parameterised by solar wind conditions

We present the first large-scale comparison of the spatial distribution of field-aligned currents as measured by the Active Magnetosphere and Planetary Electrodynamics Response Experiment, with the location and brightness of the average auroral oval, determined from the Imager for Magnetopause-to-Aurora Global Exploration far ultraviolet instrument. These distributions are compared under the same interplanetary magnetic field magnitude and clock angle conditions. The field-aligned currents and auroral oval drop to lower l ...

Carter, J.; Milan, S.; Coxon, J.; Walach, M.-T.; Anderson, B.;

YEAR: 2016     DOI: 10.1002/2015JA021567

auroral oval; field-aligned currents

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;

YEAR: 2016     DOI: 10.1051/swsc/2015041

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

Sparse Hierarchical Nonparametric Bayesian learning for light field representation and denoising

In this paper, we present a sparse hierarchical non-parametric Bayesian (SHNB) model, which is used to represent the data captured by the light field cameras. Specifically, a light field can be represented as a set of sub-aperture views. In order to capture the visual variations of these viewpoints, we propose the so-called \textquotedblleftdepth flow\textquotedblright features. Then based on the depth flow features, we model these views statistically with a sparse representation in a fully unsupervised manner. While loca ...

Sun, Xing; Meng, Nan; Xu, Zhimin; Lam, Edmund; So, Hayden;

YEAR: 2016     DOI: 10.1109/IJCNN.2016.7727617

SPIE ProceedingsThe reconnaissance and early-warning optical system design for dual field of space-based "solar blind ultraviolet"

With the development of modern technology, especially the development of information technology at high speed, the ultraviolet early warning system plays an increasingly important role. In the modern warfare, how to detect the threats earlier, prevent and reduce the attack of precision-guided missile has become a new challenge. Because the ultraviolet warning technology has high environmental adaptability, the low false alarm rate, small volume and other advantages, in the military field applications it has been developed ...

Wang, Wen-cong; Jin, Dong-dong; Shao, Fei; Hu, Hui-jun; Shi, Yu-feng; Song, Juan; Zhang, Yu-tu; Yong, Liu;

YEAR: 2016     DOI: 10.1117/12.2236440


Airglow simulation based on the Atmospheric Ultraviolet Radiance Integrated Code of 2012

The Atmospheric Ultraviolet Radiance Integrated Code (AURIC) is a software package developed by Computational Physics, Inc. (CPI) under the sponsorship of the Air Force Phillips Laboratory/Geophysics Directorate (PL/GP) (currently the Air Force Research Laboratory) for middle and upper atmospheric radiance modeling from the far ultraviolet to the near infrared. The AURIC has been considered as a general model for the radiative transfer simulation of airglow. Based on the theory of MODerate resolution atmospheric TRANsmiss ...

Wang, HouMao; Wang, YongMei;

YEAR: 2015     DOI: 10.1007/s11430-015-5166-7

airglow simulation; AURIC-2012; Limb Column Emission Intensity (L-CEI); Volume Emission Rate

NmF2 and hmF2 measurements at 95\textdegree E and 127\textdegree E around the EIA northern crest during 2010\textendash2014

The characteristics of the F2 layer parameters NmF2 and hmF2 over Dibrugarh (27.5\textdegree N, 95\textdegree E, 17\textdegree N geomagnetic, 43\textdegree dip) measured by a Canadian Advanced Digital Ionosonde (CADI) for the period of August 2010 to July 2014 are reported for the first time from this low mid-latitude station lying within the daytime peak of the longitudinal wave number 4 structure of equatorial anomaly (EIA) around the northern edge of anomaly crest. Equinoctial asymmetry is clearly observed at all solar ...

Kalita, Bitap; Bhuyan, Pradip; Yoshikawa, Akimasa;

YEAR: 2015     DOI: 10.1186/s40623-015-0355-3

Characteristics of post-midnight L-band scintillation in the transition region from the equatorial to mid-latitudes over the Indian longitude sector using COSMIC, C/NOFS and GPS measurements

Occurrence of L band scintillations around midnight and postmidnight hours have not been well studied and reported from the higher equatorial latitudes in the transition region from the equatorial to midlatitudes over the Indian longitude sector. The present paper reports cases of postmidnight L band scintillation observations by COSMIC during March 2014 over the Indian longitude sector. GPS\ S4measurements from the International Global Navigation Satellite Systems Service station at Lucknow (26.9 ...

Paul, A.; Haralambous, H.; Oikonomou, C.;

YEAR: 2015     DOI: 10.1002/2015RS005807

postmidnight L band scintillation over Indian longitude sector

Dependence of the high-latitude plasma irregularities on the auroral activity indices: a case study of 17 March 2015 geomagnetic storm

The magnetosphere substorm plays a crucial role in the solar wind energy dissipation into the ionosphere. We report on the intensity of the high-latitude ionospheric irregularities during one of the largest storms of the current solar cycle\textemdashthe St. Patrick\textquoterights Day storm of 17 March 2015. The database of more than 2500 ground-based Global Positioning System (GPS) receivers was used to estimate the irregularities occurrence and dynamics over the auroral region of the Northern Hemisphere. We analyze the ...

Cherniak, Iurii; Zakharenkova, Irina;

YEAR: 2015     DOI: 10.1186/s40623-015-0316-x

Auroral hemispheric power index Auroral precipitation; geomagnetic storm; GPS; Ionosphere irregularities; ROTI

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.;

YEAR: 2015     DOI: 10.1016/j.jastp.2015.10.021

Equatorial Electrojet; geomagnetic storm; Ionosphere

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;

YEAR: 2015     DOI: 10.1016/j.jastp.2015.09.005

Aeronomy; Ionosphere; Radar; thermosphere

Radiative transfer modeling of the OI 135.6~nm emission in the nighttime ionosphere

Remote sensing of the nighttime OI 135.6\ nm emissions has been a widely used method for measuring the\ F\ region ionospheric plasma densities. In this work, we first develop a comprehensive radiative transfer model from first principles to investigate the effects of different physical processes on the production and transport of the 135.6\ nm photons in the ionosphere and then propose a new approach for estimating electron densities from the nightglow. The forward modeling investigation indic ...

Qin, Jianqi; Makela, Jonathan; Kamalabadi, Farzad; Meier, R.;

YEAR: 2015     DOI: 10.1002/jgra.v120.1110.1002/2015JA021687

OI 135.6-nm Emission; onosphere; Radiative transfer; remote sensing

Towards estimation of atmospheric tidal effects on the ionosphere via data assimilation

The impact of atmospheric tides on the night time ionosphere is now being a subject of the extensive research within the scientific community. The plausible effect has been observed using the multiple space-borne instruments (e.g. COSMIC/FORMOSAT-3 constellation, TIMED GUVI and NASA IMAGE). Along with the observations, several modelling attempts has been undertaken to prove or refute the interrelation between the atmospheric tides and the wave-four longitudinal night time ionosphere structure. The scope of the current art ...

Solomentsev, Dmitry; Cherniak, Yakov; Titov, Anton; Khattatov, Boris; Khattatov, Vyacheslav;

YEAR: 2015     DOI: 10.1016/j.asr.2015.07.014

Atmosphere tides; data assimilation; Ionosphere longitudinal structure

Ionospheric response to the 2015 St. Patrick\textquoterights 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;

YEAR: 2015     DOI: 10.1002/2015JA021629

geomagnetic storm; hemispheric asymmetry; Ionosphere; negative storm; positive storm; Swarm mission

SPIE ProceedingsSpace-borne imager of mesospheric gravity waves

Mesospheric gravity waves play important roles in atmospheric circulation and variability. It is meaningful to obtain the features of the mesospheric gravity waves on a global scale, such as the distribution and the sources. However, limited by the field of view, the ground-based instrument can only access some local information. We developed a space-borne imager to observe the global gravity waves by collecting the O2 airglow with TDI (Time Delayed and Integration) method. The function of the imager was testified in our ...

Tu, Cui; Hu, Xiong; Xu, Qingchen; Song, Liang; Li, Hui;

YEAR: 2015     DOI: 10.1117/12.2197894

airglow imaging; gravity wave; mesosphere; space borne; TDI

Dynamics of the high-latitude ionospheric irregularities during the 17 March 2015 St. Patrick\textquoterights 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;

YEAR: 2015     DOI: 10.1002/swe.v13.910.1002/2015SW001237

auroral precipitation; geomagnetic storm; Ionosphere; irregularities; rate of TEC

Impacts of CME-induced geomagnetic storms on the midlatitude mesosphere and lower thermosphere observed by a sodium lidar and TIMED/GUVI

In this paper, we report our findings on the correlation between the neutral temperature (around the mesopause) and thermospheric column density O/N2\ ratio, along with their response to geomagnetic storms above midlatitude of North America. A temperature/wind Doppler Na lidar, operating at Fort Collins, CO (41\textdegreeN, 105\textdegreeW), and later at Logan, UT (42\textdegreeN and 112\textdegreeW), observed significant temperature increases (temperature anomaly) above 95 km (as much as 55 K at 105 km al ...

Yuan, T.; Zhang, Y.; Cai, X.; She, C.-Y.; Paxton, L.;

YEAR: 2015     DOI: 10.1002/2015GL064860

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