GUVI Biblio





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Found 665 entries in the Bibliography.


Showing entries from 51 through 100


2019

Signatures of Sudden Storm Commencement on the equatorial thermospheric dayglow

It has been observed that the OI 630.0\ nm dayglow emission over a dip equatorial station, Trivandrum (8.5\textdegree\ N, 77\textdegree\ E, dip 0.5\textdegree\ N), India registered an abrupt increase of\ ~\ 2000\ R during the compression phase of the magnetosphere as dictated by a sudden increase in solar wind ram pressure. Furthermore, an unusual depletion of these emissions has been observed during the eastward interplanetary electric field (IEF), concomitant with southward excursion o ...

Sumod, Sukumarn; Pant, Tarun; Ajesh, Asokan;

YEAR: 2019     DOI: 10.1051/swsc/2019026

Wide-field auroral imager onboard the Fengyun satellite

The newly launched Fengyun-3D (FY-3D) satellite carried a wide-field auroral imager (WAI) that was developed by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences (CIOMP), which will provide a large field of view (FOV), high spatial resolution, and broadband ultraviolet images of the aurora and the ionosphere by imaging the N2 LBH bands of emissions. The WAI consists of two identical cameras, each with an FOV of 68\textdegree in the along-track direction and 10\textdegree in ...

Zhang, Xiao-Xin; Chen, Bo; He, Fei; Song, Ke-Fei; He, Ling-Ping; Liu, Shi-Jie; Guo, Quan-Feng; Li, Jia-Wei; Wang, Xiao-Dong; Zhang, Hong-Ji; Wang, Hai-Feng; Han, Zhen-Wei; Sun, Liang; Zhang, Pei-Jie; Dai, Shuang; Ding, Guang-Xing; Chen, Li-Heng; Wang, Zhong-Su; Shi, Guang-Wei; Zhang, Xin; Yu, Chao; Yang, Zhong-Dong; Zhang, Peng; Wang, Jin-Song;

YEAR: 2019     DOI: 10.1038/s41377-019-0157-7

Annual and Semiannual Oscillations of Thermospheric Composition in TIMED/GUVI Limb Measurements

The Global UltraViolet Imager (GUVI) onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite provides a data set of vertical thermospheric composition (O, N2, and O2 densities) and temperature profiles from 2002\textendash2007. Even though GUVI sampling is limited by orbital constraint, we demonstrated that the GUVI data set can be used to derive the altitude profiles of the amplitudes and phases of annual oscillation (AO) and semiannual oscillation (SAO), thereby pro ...

Yue, Jia; Jian, Yongxiao; Wang, Wenbin; Meier, R.R.; Burns, Alan; Qian, Liying; Jones, M.; Wu, Dong; Mlynczak, Martin;

YEAR: 2019     DOI: 10.1029/2019JA026544

Seasonal Variations of Low-Latitude Migrating and Nonmigrating Diurnal and Semidiurnal Tides in TIMED-SABER Temperature and Their Relationship With Source Variations

Seasonal and source variations of migrating and nonmigrating tides are studied using Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics-Sounding of the Atmosphere using Broadband Emission Radiometry temperature data at 10\textdegreeN (5\textendash15\textdegreeN) for the year 2009. The migrating DW1 shows equinoctial maximum and summer minimum at low latitudes. It shows equinoctial asymmetry with larger amplitudes during spring equinox than fall equinox. The migrating semidiurnal tidal amplitude (SW2) shows larger ...

Sridharan, S.;

YEAR: 2019     DOI: 10.1029/2018JA026190

Comparison of Thermospheric Density Between GUVI Dayside Limb Data and CHAMP Satellite Observations: Based on Empirical Model

The Global Ultraviolet Imager (GUVI) aboard the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite senses far ultraviolet airglow emissions in the thermosphere. The retrieved altitude profiles of thermospheric neutral density from GUVI daytime limb scans are significant for ionosphere-thermosphere study. Here, we use the profiles of the main neutral density to derive the total mass density during the period 2002\textendash2007 under geomagnetic quiet conditions (ap\ \<\ =12) ...

Yu, Tingting; Ren, Zhipeng; Yue, Xinan; Yu, You; Wan, Weixing;

YEAR: 2019     DOI: 10.1029/2018JA026229

Evaluation of Space Traffic Effects in SBUV Polar Mesospheric Cloud Data

Water-rich rocket exhaust plumes, in particular those emitted by the National Aeronautics and Space Administration Space Shuttle, have been suggested to make a significant contribution to long-term trends in polar mesospheric cloud (PMC) ice water content. We investigate this claim using the combined Solar Backscatter Ultraviolet (SBUV) PMC data record from eight separate instruments, which includes 60 Shuttle launches during PMC seasons between 1985 and 2011. No statistically significant postlaunch signal in PMC total ic ...

DeLand, Matthew; Thomas, Gary;

YEAR: 2019     DOI: 10.1029/2018JD029756

Inferring thermospheric composition from ionogram profiles: A calibration with the TIMED spacecraft

Measurements of thermospheric composition via ground-based instrumentation are challenging to make and so details about this important region of the upper atmosphere are currently sparse. We present a technique thatdeducesquantitative estimates of thermospheric composition from ionospheric data, for which there is a global network of stations. The visibility of the F1 peak in ionospheric soundings from ground-based instrumentation is a sensitive function of thermospheric composition. The ionospheric profile in the transit ...

Scott, Christopher; Jones, Shannon; Barnard, Luke;

YEAR: 2019     DOI: 10.5194/angeo-2019-4710.5194/angeo-2019-47-RC110.5194/angeo-2019-47-RC2

L-band scintillation and TEC variations on St. Patrick\textquoterights Day storm of 17 March 2015 over Indian longitudes using GPS and GLONASS observations

The aim of the present study is to investigate the response of ionospheric total electron content (TEC), Global Positioning System (GPS) and Global Navigation Satellite System (GLONASS) scintillations during 17 March 2015 St. Patrick\textquoterights Day geomagnetic storm over Visakhapatnam, which is popularly known as Waltair (WALT) in the literature. GPS TEC observations obtained from five IGS stations (SGOC, IISC, HYDE, LCK4 and LHAZ) and WALT during the storm have been compared. The TEC derived from GPS, GLONASS conste ...

Srinivasu, K; Prasad, D; Niranjan, K; Seemala, Gopi; Venkatesh, K;

YEAR: 2019     DOI: 10.1007/s12040-019-1097-6

An Observational Review on influence of Intense Geomagnetic Storm on Positional Accuracy of NavIC/IRNSS System

The positional accuracy of Navigation with the Indian Constellation (NavIC)/Indian Regional Navigation Satellite System (IRNSS) in the low latitudes of the Indian region during the intense geomagnetic storm of 8 September 2017 being reported first time. The existence of an intense geomagnetic storm is verified with several geomagnetic indices and interplanetary field parameters. The Total Electron Content (TEC) maps from the International GNSS Service (IGS) data and the thermosphere O/N2 ratio maps from the Global Ultra V ...

Desai, Mehul; Shah, Shweta;

YEAR: 2019     DOI: 10.1080/02564602.2019.1599739

Observations of conjugated ring current auroras at subauroral latitudes

We report three ring current aurora events that are conjugated in the two hemispheres observed by satellite and ground imagers on May 16, 2005, August 26, 2018 and September 5, 2005. The ring current auroras appeared as auroral spots or arcs in the day, dusk or night side. These events confirm that the particle sources are in the equatoria ...

Zhang, Yongliang; Paxton, Larry;

YEAR: 2019     DOI: 10.1016/j.jastp.2019.01.005

Plasma Blobs Associated With Medium-Scale Traveling Ionospheric Disturbances

Plasma blobs represent plasma density enhancements with respect to ambient plasma. The formation of blobs in low and middle latitudes is understood in association with either equatorial plasma bubbles or medium-scale traveling ionospheric disturbances (MSTIDs). This study reports four blob events identified from the Swarm satellite observations in 2014. Those blobs show the conjugate property and the alignment in the northwest-southeast direction in the Northern Hemisphere and southwest-northeast direction in the Southern ...

Kil, Hyosub; Paxton, Larry; Jee, Geonhwa; Nikoukar, Romina;

YEAR: 2019     DOI: 10.1029/2019GL082026

Plasma transport process in the equatorial/low-latitude ionosphere

The behaviour of the equatorial/low-latitude ionosphere and the transport processes during magnetic disturbed and quiet periods of a high solar activity year, 2014, in the American sector are investigated. Parameters used include vertical drift (Vz), transport term (W), NmF2, hmF2 and scale-height (H). The F2 plasma variations followed the diurnal local solar pattern, being higher at daytime. The sunset maximum and sunrise minimum peaks of hmF2 were directly opposite to the scale height ...

Adebesin, Babatunde; Adekoya, Bolarinwa; David, Timothy;

YEAR: 2019     DOI: 10.1016/j.asr.2018.11.013

Hemispheric Asymmetry of the Premidnight Aurora Associated With the Dawn-Dusk Component of the Interplanetary Magnetic Field

It has been known for decades that the nightside aurora in the Northern Hemisphere (NH) tends to be brighter when the interplanetary magnetic field (IMF) measured at Earth has a dawnward (negative y) component compared to a duskward (positive y) component. This asymmetric response to the polarity of IMF By has been explained by an interhemispheric current flowing out of the NH due to a nonuniform \textquotedblleftpenetration\textquotedblright of IMF By< ...

Liou, K.; Mitchell, E.;

YEAR: 2019     DOI: 10.1029/2018JA025953

Spatial asymmetry in topside ion density and vertical E \texttimes B plasma drift velocity within 75\textdegreeE\textendash95\textdegreeE

The ion density measured by the Ionospheric Plasma and Electrodynamics Instrument (IPEI) on board the ROCSAT -1 over the 75\textdegreeE and ...

Kakoty, Rimpy; Bora, Saradi; Bhuyan, Pradip;

YEAR: 2019     DOI: 10.1016/j.asr.2018.10.013

Impact of nitric oxide, solar EUV and particle precipitation on thermospheric density decrease

Longitudinal variations of the ionospheric trough position

For the first time a comprehensive pattern of the longitudinal effect of the ionospheric trough position was obtained. We present new results with longitudinal variations of the winter trough position as a function of geomagnetic latitude for both hemispheres and conditions of high and low solar activity and all local time hours. We used a large observational data set obtained onboard the Kosmos-900, Interkosmos-19 and CHAMP satellites for quiet geomagnetic conditions. We found that a magnitude of the trough position long ...

Karpachev, A.T.; Klimenko, M.V.; Klimenko, V.V.;

YEAR: 2019     DOI: 10.1016/j.asr.2018.09.038

Space Weather Modeling Capabilities Assessment: Auroral Precipitation and High-Latitude Ionospheric Electrodynamics

As part of its International Capabilities Assessment effort, the Community Coordinated Modeling Center initiated several working teams, one of which is focused on the validation of models and methods for determining auroral electrodynamic parameters, including particle precipitation, conductivities, electric fields, neutral density and winds, currents, Joule heating, auroral boundaries, and ion outflow. Auroral electrodynamic properties are needed as input to space weather models, to test and validate the accuracy of phys ...

Robinson, Robert; Zhang, Yongliang; Garcia-Sage, Katherine; Fang, Xiaohua; Verkhoglyadova, Olga; Ngwira, Chigomezyo; Bingham, Suzy; Kosar, Burcu; Zheng, Yihua; Kaeppler, Stephen; Liemohn, Michael; Weygand, James; Crowley, Geoffrey; Merkin, Viacheslav; McGranaghan, Ryan; Mannucci, Anthony;

YEAR: 2019     DOI: 10.1029/2018SW002127

Effect of MgF2 deposition temperature on Al mirrors in vacuum ultraviolet

High reflectivity of mirrors is very important for many applications in the vacuum ultraviolet, such as for space observation, synchrotron radiation. This paper focuses on the substrate temperature\textquoterights effect on the performance of Al mirrors when depositing the upper MgF2 layer. Al films are deposited on the substrates at room temperature by thermal evaporation, and a 5 nm MgF2 film is deposited on Al coating at room temperature immediately. Heating the substrate to various temperatures r ...

Wang, Fengli; Li, Shuangying; Zhang, Zhuangzhuang; Wang, Zhanshan; Zhou, Hongjun; Huo, Tonglin;

YEAR: 2019     DOI: 10.1117/12.2540004

2018

Latitudinal variation of F-region ionospheric response during three strongest geomagnetic storms of 2015

The latitudinal ionospheric response of the three strongest geomagnetic storms of 2015 of the current solar cycle 24 during 16\textendash19 March 2015, 21\textendash24 June 2015 and 19\textendash22 December 2015 is investigated using the total electron content data derived from a latitudinal chain of Global Positioning System (GPS) receivers extending from 70\textdegreeN to 70\textdegreeS. The storm time perturbations of the ionosphere during main and recovery phase is presented by the GPS derived vertical total electron ...

Paul, Bapan; De, Barin; Guha, Anirban;

YEAR: 2018     DOI: 10.1007/s40328-018-0221-4

Observation of equatorial plasma bubbles by the airglow imager on ISS-IMAP

Using 630 nm airglow data observed by an airglow imager on the International Space Station (ISS), the occurrence of equatorial plasma bubbles (EPBs) is studied. In order to examine the physical mechanisms in the boundary region between the Earth and the outer space, an ionosphere, mesosphere, upper atmosphere, and plasmasphere mapping (IMAP) mission had been conducted onboard the ISS since October 2012. The visible light and infrared spectrum imager (VISI) is utilized in the ISS-IMAP mission for nadir-looking observation ...

Nakata, Hiroyuki; Takahashi, Akira; Takano, Toshiaki; Saito, Akinori; Sakanoi, Takeshi;

YEAR: 2018     DOI: 10.1186/s40645-018-0227-0

Space Weather Events, Hurricanes, and Earthquakes in Mexico in September 2017

In the interval of 4\textendash10 September 2017, the Sun presented multiple solar flares from active region AR 2673. There were also coronal mass ejections that interacted with the Earth\textquoterights magnetosphere. This solar activity produced several space weather events. These events were observed with ground-based instruments of the Mexican Space Weather Service. The Mexican Array RadioTelescope detected highly perturbed solar transits associated with Type I radio emissions from active regions. The Compact Astronom ...

Gonzalez-Esparza, J.; Sergeeva, M.; Corona-Romero, P.; Mejia-Ambriz, J.; Gonzalez, L.; De la Luz, V.; Aguilar-Rodriguez, E.; Rodriguez, M.; andez, Romero-Hern\;

YEAR: 2018     DOI: 10.1029/2018SW001995

First Time Estimation of Thermospheric Neutral Density Profiles From Seed Perturbations of ESF Triggering: A Novel Evidence for Ionosphere Thermosphere Coupling

The present study reveals the coupling between the neutral densities, derived from the Global Ultraviolet Imager satellite and the requisite gravity wave seed perturbations for equatorial spread F occurrence (Manju et al., 2016, https://doi.org/10.1016/j.asr.2015.12.019), derived from the ionosonde data at Trivandrum (8.5\textdegreeN, 77\textdegreeE). Further, the relation between the above two parameters is found to have solar flux depe ...

Manju, G.; Aswathy, R.;

YEAR: 2018     DOI: 10.1029/2018JA025967

The ionosphere response to severe geomagnetic storm in March 2015 on the base of the data from Eurasian high-middle latitudes ionosonde chain

The pattern of ionospheric disturbances caused by complex interplanetary structure on 19\textendash22 December 2015

The pattern of the ionospheric storm that was observed during the severe two-step geomagnetic storm on 19\textendash22 December 2015 in ...

Kurkin, V.I.; Polekh, N.M.; Zolotukhina, N.A.;

YEAR: 2018     DOI: 10.1016/j.jastp.2018.07.003

Transition of Interhemispheric Asymmetry of Equatorial Ionization Anomaly During Solstices

The magnitudes of the two crests of equatorial ionization anomaly (EIA) vary with local time. During the solstices, EIA crest in the winter hemisphere is larger than that in the summer hemisphere before noon/early afternoon. Whereafter, the crest in the summer hemisphere becomes intensified, and the stronger EIA crest transits to the summer hemisphere. Using Constellation Observing System for Meteorology, Ionosphere, and Climate ionospheric radio occultation data, we examine the longitudinal and altitudinal variations of ...

Huang, He; Lu, Xian; Liu, Libo; Wang, Wenbin; Li, Qiaoling;

YEAR: 2018     DOI: 10.1029/2018JA026055

Tropical Ionization Trough in the Ionosphere Seen by Swarm-A Satellite

A new type of ionization trough, the tropical ionization trough, is identified in the tropical F region from the Swarm-A satellite observations in December 2013 to January 2017. The trough is formed around midnight near 25\textdegree magnetic latitudes in the winter hemisphere during the solstices. The trough is pronounced around 330\textdegreeE longitude in the Southern Hemisphere (negative magnetic declination) during the June solstices and around 210\textdegreeE longitude in the Northern Hemisphere (p ...

Lee, Woo; Kil, Hyosub; Paxton, Larry;

YEAR: 2018     DOI: 10.1029/2018GL080286

A case study comparing citizen science aurora data with global auroral boundaries derived from satellite imagery and empirical models

Comparison of the Thermospheric Nitric Oxide Emission Observations and the GITM Simulations: Sensitivity to Solar and Geomagnetic Activities

An accurate estimate of the energy budget (heating and cooling) of the ionosphere and thermosphere, especially during space weather events, has been a challenge. The abundance of Nitric Oxide (NO), a minor species in the thermosphere, is an important component of energy balance here because its production comes from energy sources able to break the strong bond of molecular nitrogen, and infrared emissions from NO play an important role in thermospheric cooling. Recent studies have significantly improved our understanding ...

Lin, Cissi; Deng, Yue; Venkataramani, Karthik; Yonker, Justin; Bailey, Scott;

YEAR: 2018     DOI: 10.1029/2018JA025310

Ionospheric and Thermospheric Responses to the Recent Strong Solar Flares on 6 September 2017

Two solar flares X2.2 and X9.3 erupted over the active region 2673 on 6 September 2017, and the second flare is the strongest since 2005. In order to investigate the ionospheric and thermospheric responses to the two solar flares, the global total electron content and the critical frequency of F2 layer obtained from GPS stations and ionosondes are used. The results indicate that the ionosphere in the sunlit hemisphere increased significantly with magnitudes of 0.1 and 0.5 total electron content units for the X2.2 and X9.3 ...

Li, Wang; Yue, Jianping; Yang, Yang; He, Changyong; Hu, Andong; Zhang, Kefei;

YEAR: 2018     DOI: 10.1029/2018JA025700

Local Time Hemispheric Asymmetry in Nitric Oxide Radiative Emission During Geomagnetic Activity

The nitric oxide (NO) radiative emission at 5.3\ μm cools the thermosphere by conversion of solar energy into infrared radiation subsequently exiting thermosphere. It correctly serves as a natural thermostat. The NO 5.3-μm emission is even more important during geomagnetic storm events due to huge deposition of heat energy and momentum in the Earth\textquoterights atmosphere. The Thermosphere, Ionosphere, Mesosphere Energetics, and Dynamics-Sounding of the Atmosphere using Broadband Emission Radiometry obs ...

Bag, Tikemani;

YEAR: 2018     DOI: 10.1029/2018JA025731

Ionospheric response to solar EUV variations: Preliminary results

We investigate the ionospheric response to solar Extreme Ultraviolet (EUV) variations using different proxies, based on solar EUV spectra observed from the Solar Extreme Ultraviolet Experiment (SEE) onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite, the F10.7 index (solar irradiance at 10.7cm), and the Bremen composite Mg-II index during January 2003 to December 2016. The daily mean solar proxies are compared with global mean Total Electron Content (GTEC) values calculated from globa ...

Vaishnav, Rajesh; Jacobi, Christoph; Berdermann, Jens; Schmölter, Erik; Codrescu, Mihail;

YEAR: 2018     DOI: 10.5194/ars-16-157-2018

Nonparametric H Density Estimation Based on Regularized Nonlinear Inversion of the Lyman Alpha Emission in Planetary Atmospheres

Inversion of space-borne remote sensing measurements of the resonantly scattered solar Lyman alpha (121.6-nm) emission in planetary atmospheres is the most promising means of quantifying the H density in a vast volume of space near terrestrial planets. Owing to the highly nonlinear nature of the inverse problem and the lack of sufficient data constraints over the large volume of space where H atoms are present, previous inversion methods relied on physics-based parametric formulations of the H density distributions to gua ...

Qin, Jianqi; Harding, Brian; Waldrop, Lara;

YEAR: 2018     DOI: 10.1029/2018JA025954

On the Responses of Mesosphere and Lower Thermosphere Temperatures to Geomagnetic Storms at Low and Middle Latitudes

Observations from lidars and satellites have shown that large neutral temperature increases and decreases occur in the middle and low latitudes of the mesosphere and lower thermosphere region during geomagnetic storms. Here we undertake first-principles simulations of mesosphere and lower thermosphere temperature responses to storms using the Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model to elucidate the nature and causes of these changes. Temperature variations were not uniform; instead, ni ...

Li, Jingyuan; Wang, Wenbin; Lu, Jianyong; Yuan, Tao; Yue, Jia; Liu, Xiao; Zhang, Kedeng; Burns, Alan; Zhang, Yongliang; Li, Zheng;

YEAR: 2018     DOI: 10.1029/2018GL078968

Changes in the middle and upper atmosphere parameters during the January 2013 sudden stratospheric warming

We present the results of complex obser-vationsof various parameters of the middle and upper atmosphere over Siberia in December 2012 \textendashJanuary 2013, during a major sudden stratospheric warming (SSW) event. We analyze variations in ozone concentra-tion from microwave measurements, in stratosphere and lower mesosphere temperatures from lidar and satellite measurements, in the F2-layer critical frequency (foF2), in the total electron content (TEC), as well as in the ra-tio of concentrations of atomic oxygen to mole ...

Ясюкевич, Анна; Yasyukevich, Anna; Клименко, Максим; Klimenko, Maksim; Куликов, Юрий; Kulikov, Yury; Клименко, Владимир; Klimenko, Vladimir; Бессараб, Федор; Bessarab, Fedor; Кореньков, Юрий; Korenkov, Yuriy; Маричев, Валерий; Marichev, Valery; Ратовский, Константин; Ratovsky, Konstantin; Колесник, Сергей; Kolesnik, Sergey;

YEAR: 2018     DOI: 10.12737/issue_5c1b83b913d443.7589563310.12737/szf-44201807

Investigation of the Causes of the Longitudinal and Solar Cycle Variation of the Electron Density in the Bering Sea and Weddell Sea Anomalies

This paper investigates and quantifies the longitudinal, solar cyclical, and diurnal variation of the ionosphere peak electron density observed by six ionosondes located between 18 and 151\textdegreeE near 60\textdegreeN. Embedded within this region is the Bering Sea anomaly (BSA) where the midnight peak electron density exceeds the midday peak electron density in summer. The BSA is a region West of Alaska extending from approximately 100\textdegree to 200\textdegree east geographic longitude and 55\textdegree to 70\textd ...

Richards, P.; Meier, R.; Chen, Shihping; Dandenault, P.;

YEAR: 2018     DOI: 10.1029/2018JA025413

IPIM Modeling of the Ionospheric F 2 Layer Depletion at High Latitudes During a High-Speed Stream Event

Our aim is to understand the effect of high-speed stream events on the high-latitude ionosphere and more specifically the decrease of the foF2 frequency during the entire day following the impact. First, we have selected one summertime event, for which a large data set was available: Super Dual Auroral Radar Network (SuperDARN) and European Incoherent SCATter (EISCAT) radars, Troms\o and Sodankylä ionosondes, and the CHAllenging Minisatellite Payload (CHAMP) satellite. We ...

Marchaudon, A.; Blelly, P.-L.; Grandin, M.; Aikio, A.; Kozlovsky, A.; Virtanen, I.;

YEAR: 2018     DOI: 10.1029/2018JA025744

Nighttime Enhancements in the Midlatitude Ionosphere and Their Relation to the Plasmasphere

In situ electron density measurements by the CHAllenging Minisatellite Payload and the Defense Meteorological Satellites Program F17 satellites show that the midlatitude ionization at altitudes of \~350 and 850\ km is enhanced in the late evening. The enhancements increase to maximum around midnight and are clearly observed till early morning as the equatorial ionization decays to minimal level. They appear in the winter hemisphere during June and December solstices and in both hemispheres during equinox. The enhance ...

Li, Quanhan; Hao, Yongqiang; Zhang, Donghe; Xiao, Zuo;

YEAR: 2018     DOI: 10.1029/2018JA025422

Signatures of the Solar Transient Disturbances Over the Low Latitude Ionosphere During 6 to 8 September 2017

Low latitude ionospheric behavior during solar transient disturbances of solar flares and storm time penetrating electric fields comprises an important part of the Earth\textquoterights space weather. The flares enhance the electron density of the sunlit ionosphere by supplying excess solar radiation. However, the degree of these density changes is subjective if a geomagnetic storm persists simultaneously. The present case study addresses the ionospheric variations over the Indian longitudes under the combined effects of ...

Bagiya, Mala; Thampi, Smitha; Hui, Debrup; Sunil, A.; Chakrabarty, D.; Choudhary, R.;

YEAR: 2018     DOI: 10.1029/2018JA025496

Statistical Relations Between Field-Aligned Currents and Precipitating Electron Energy Flux

Measurements of field-aligned currents from the Active Magnetosphere and Planetary Electrodynamics Response Experiment are combined with measurements of far ultraviolet emissions from the Global Ultraviolet Imager on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics satellite to examine the correlation between parallel currents and auroral electron energy flux. The energy flux is derived from the far ultraviolet emissions in the N2 Lyman-Birge-Hopfield bands. We find that energy flux correlates wit ...

Robinson, R.; Zhang, Y.; Anderson, B.; Zanetti, L.; Korth, H.; Fitzmaurice, A.;

YEAR: 2018     DOI: 10.1029/2018GL078718

An Empirical Dayglow Model for the Lyman-Birge-Hopfield-Long Band Derived From the Polar Ultraviolet Imager Data

The Lyman-Birge-Hopfield-long band dayglow emissions near 1,700\ \r A, which were observed by the ultraviolet imager on board Polar satellite, are characterized as a cosine-like function of the solar zenith angle. These emissions are mainly excited by the solar extreme ultraviolet produced photoelectrons acting on the nitrogen molecules. The amplitude and phase factors are used to quantify the cosine-like function and subsequently develop a dayglow model. In this study, a model is developed by considering broader day ...

Wang, Lingmin; Luan, Xiaoli; Lei, Jiuhou; Dou, Xiankang;

YEAR: 2018     DOI: 10.1029/2018SW001954

Observations of Spatial Variations in O/N 2 During an Auroral Substorm Using the Multichannel Downlooking Camera on the VISIONS Rocket

At 0821 UT on 7 February 2013, during an auroral substorm, the NASA VISIONS rocket was launched northward from Poker Flat Research Range on a flight to approximately 750-km altitude that terminated in the Arctic Ocean. A subpayload jettisoned on the up leg carried a multichannel optical imager that looked downward and observed the auroral emission through four narrow passband filters. Three of the channels had sufficiently strong signal to allow a measure of the time evolution of the horizontal extent of the electron auro ...

Hecht, J.; Clemmons, J.; Conde, M.; Hampton, D.; Michell, R.; Rowland, D.; Pfaff, R.; Walterscheid, R.;

YEAR: 2018     DOI: 10.1029/2018JA025288

Auroral Ionospheric E Region Parameters Obtained From Satellite-Based Far Ultraviolet and Ground-Based Ionosonde Observations: Data, Methods, and Comparisons

A large number (~1,000) of coincident auroral far ultraviolet (FUV) and ground-based ionosonde observations are compared. This is the largest study to date of coincident satellite-based FUV and ground-based observations of the auroral E region. FUV radiance values from the NASA Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics Global Ultraviolet Imager and the Defense Meteorological Satellite Program F16 and F18 Special Sensor Ultraviolet Spectrographic Imager are included in the study. A method is des ...

Knight, H.; Galkin, I.; Reinisch, B.; Zhang, Y.;

YEAR: 2018     DOI: 10.1029/2017JA024822

Modeling study of the ionospheric responses to the quasi-biennial oscillations of the sun and stratosphere

ROTI Maps: a new IGS ionospheric product characterizing the ionospheric irregularities occurrence

The International GNSS Service (IGS) has recently accepted for official release a new ionospheric product to characterize ionospheric irregularity and intensity as derived from multi-site ground-based GPS observations. This product was developed and implemented in the Space Radio-Diagnostic Research Center (SRRC), University of Warmia and Mazury. The SRRC has implemented this approach using in-house software for multi-step processing and interpretation of carrier phase delays in dual-frequency GPS signals and provides the ...

Cherniak, Iurii; Krankowski, Andrzej; Zakharenkova, Irina;

YEAR: 2018     DOI: 10.1007/s10291-018-0730-1

Effect of geomagnetic storms on the daytime low-latitude thermospheric wave dynamics

High-Latitude Observations of a Localized Wind Wall and Its Coupling to the Lower Thermosphere

Reversals in the thermospheric zonal winds at altitudes of 140 to 250\ km from eastward to westward have been found at southern geographic latitudes between 60\textdegree and 70\textdegree. These are confined to a narrow region between 100\textdegree and 200\textdegree in longitude with zonal velocities regularly of -400\ m/s, sometimes reaching -600\ m/s, so sharply defined that the authors describe it as a \textquotedblleftwind wall.\textquotedblright The observations were made by the Wind Imaging Interfe ...

Shepherd, Gordon; Shepherd, Marianna;

YEAR: 2018     DOI: 10.1029/2018GL077722

Solar activity variations of equatorial spread F occurrence and sustenance during different seasons over Indian longitudes: Empirical model and causative mechanisms

A comprehensive analysis using nearly two decades of ionosonde data is carried out on the seasonal and solar cycle variations of Equatorial Spread F (ESF) irregularities over magnetic equatorial location Trivandrum (8.5\textdegreeN, 77\textdegreeE). The corresponding Rayleigh Taylor (RT) instability growth rates (γ) are also estimated. A seasonal pattern of ESF occurrence and the corresponding γ is established for low solar (LSA), medium solar (MSA) and high solar (HSA) activity p ...

Haridas, M.K.; Manju, G.; Arunamani, T.;

YEAR: 2018     DOI: 10.1016/j.asr.2018.02.040

Multivariable Comprehensive Analysis of Two Great Geomagnetic Storms of 2015

During the year 2015 two great geomagnetic storms (Dst\ \<\ -200\ nT) occurred on 17 March and 22 June. These two geomagnetic storms have similarities. They occurred during the same decreasing phase of the sunspot cycle 24. The interplanetary and magnetospheric environments were calm before the beginning of the storms. Both events were due to Coronal Mass Ejections and High-Speed Solar Wind. Variations of the solar wind velocity and the Bz component of the interplanetary magnetic field were also similar. ...

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

YEAR: 2018     DOI: 10.1029/2017JA024900

Storm-time variations of atomic nitrogen 149.3 nm emission

Net radiances of atomic nitrogen emission line (N-149.3 nm) from the thermosphere are extracted from the FUV spectra observed by TIMED/GUVI on dayside at ...

Zhang, Y.; Paxton, L.J.; Morrison, D.; Schaefer, B.;

YEAR: 2018     DOI: 10.1016/j.jastp.2018.01.023

Variations in Ionospheric Peak Electron Density During Sudden Stratospheric Warmings in the Arctic Region

The focus of the paper is the ionospheric disturbances during sudden stratospheric warming (SSW) events in the Arctic region. This study examines the ionospheric behavior during 12 SSW events, which occurred in the Northern Hemisphere over 2006\textendash2013, based on vertical sounding data from DPS-4 ionosonde located in Norilsk (88.0\textdegreeE, 69.2\textdegreeN). Most of the addressed events show that despite generally quiet geomagnetic conditions, notable changes in the ionospheric behavior are observed during SSWs. ...

Yasyukevich, A.;

YEAR: 2018     DOI: 10.1002/jgra.v123.410.1002/2017JA024739



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