Bibliography
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Notice:
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Found 672 entries in the Bibliography.
Showing entries from 151 through 200
| 2020 |
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Global-scale observations and modeling of far-ultraviolet airglow during twilight The NASA Global‐scale Observations of the Limb and Disk ultraviolet imaging spectrograph performs observations of upper atmosphere airglow from the sunlit disk and limb of the Earth Solomon, Stanley; Andersson, Laila; Burns, Alan; Eastes, Richard; Martinis, Carlos; McClintock, William; Richmond, Arthur; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2019JA027645 |
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Daily Variability in the Terrestrial UV Airglow New capability for observing conditions in the upper atmosphere comes with the implementation of global ultraviolet (UV) imaging from geosynchronous orbit. Observed by the NASA Immel, Thomas; Eastes, Richard; McClintock, William; Mende, Steven; Frey, Harald; Triplett, Colin; England, Scott; Published by: Atmosphere Published on: YEAR: 2020 DOI: 10.3390/atmos11101046 |
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The Global-scale Observations of the Limb and Disk (GOLD) instrument was launched on 25 January 2018 onboard the SES-14 commercial communications satellite and began nominal science operations in October 2018. Operating from geostationary orbit at 47.5°W longitude, GOLD images the Earth s thermosphere and ionosphere in the far-ultraviolet (132–162 nm), measuring critical geophysical parameters by continuously scanning the Earth s disk and limb 18 hours per day. GOLD also performs stellar occultation measurements using bright type O and B stars. Lumpe, JD; McClintock, WE; Evans, JS; Correira, J; , Veibell; Beland, S; Eastes, R; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2020JA027812 |
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Yasyukevich (2018) showed an increase in the daytime GUVI [O/N2] along 88E during the peak and decaying period of major warmings. Furthermore, Pedatella et al. (2016), using Kakoti, Geetashree; Kalita, Bitap; Bhuyan, PK; Baruah, S; Wang, K; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2020JA028570 |
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Challenges to understanding the Earth s ionosphere and thermosphere We discuss, in a limited way, some of the challenges to advancing our understanding and description of the coupled plasma and neutral gas that make up the ionosphere and Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2020 DOI: 10.1029/2019JA027497 |
| 2019 |
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Klimenko, V.V.; Klimenko, M.V.; Bessarab, F.S.; Sukhodolov, T.V.; Rozanov, E.V.; Published by: Advances in Space Research Published on: 11/2019 YEAR: 2019 DOI: 10.1016/j.asr.2019.06.029 |
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Klimenko, V.V.; Klimenko, M.V.; Bessarab, F.S.; Sukhodolov, T.V.; Rozanov, E.V.; Published by: Advances in Space Research Published on: 11/2019 YEAR: 2019 DOI: 10.1016/j.asr.2019.06.029 |
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Effects of the interplanetary magnetic field y component on the dayside aurora A dawn\textendashdusk asymmetry in many high-latitude ionospheric and magnetospheric phenomena, including the aurora, can be linked to the east\textendashwest (y) component of the interplanetary magnetic field (IMF). Owing to the scarcity of observations in the Southern Hemisphere, most of the previous findings are associated with the Northern Hemisphere. It has long been suspected that if the IMF By component also produces a dawn\textendashdusk asymmetry and/or a mirror image in the Southern Hemisphere as predicted by some theories. The present study explores the effect of the IMF By component on the dayside aurora from both hemispheres by analyzing the auroral emission data from the Global UltraViolet scanning spectrograph Imager on board the Thermosphere Ionosphere Mesosphere Energetics and Dynamics mission spacecraft from 2002 to 2007. The data set comprises 28,774 partial images of the northern hemispheric oval and 29,742 partial images of the southern hemispheric oval, allowing for a statistical analysis. It is found that even though auroras in different regions of the dayside oval respond differently to the orientation of the IMF By component, their responses are opposite between the two hemispheres. For example, at ~ 1400\textendash1600\ MLT in the Northern Hemisphere, where the so-called 1500\ MLT auroral hot spots occur, peak auroral energy flux is larger for negative IMF By comparing to positive IMF By. The response is reversed in the Southern Hemisphere. The present study also suggests that the total energy flux does not change with the IMF By orientation change. This result is consistent with a larger (smaller) convection vortex in the postnoon sector for IMF By \< 0 (By \> 0) resulting from anti-parallel merging. Published by: Geoscience Letters Published on: 11/2019 YEAR: 2019 DOI: 10.1186/s40562-019-0141-3 |
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The geomagnetic storm-driven ionospheric changes and the involved processes are interesting and challenging topics in understanding and predicting the ionosphere. In this study we investigate the response of the ionosphere to geomagnetic disturbances during the 30-day incoherent scatter radar measurements conducted at Millstone Hill (42.6\textdegreeN, 71.5\textdegreeW) from 4 October to 4 November 2002. During geomagnetically disturbed periods, while the peak electron density of the F2 layer (NmF2) and total electron content deviate remarkably from the quiet time ones in a similar way, the incoherent scatter radar measurements reveal that the changes in electron density are frequently different between low and high altitudes. The electron density is significantly depleted at low altitudes; however, at topside it either changes slightly or sometime is enhanced. The enhanced vertical scale height around 600 km under geomagnetically active conditions implies that the topside electron density profiles become much steeper. The increase in the peak height of F2 layer (hmF2) indicates the upward motions under the action of the storm-driven dynamic processes. Further, sometimes strong differences are shown in total electron content between Millstone Hill and longitude 100\textdegreeW. The competing contributions from dynamic processes and disturbance composition to the storm-time ionospheric changes over Millstone Hill are indicated in the different responses in electron density at the bottomside and topside of the ionosphere. Liu, Libo; Le, Huijun; Chen, Yiding; Zhang, Ruilong; Wan, Weixing; Zhang, Shun-Rong; Published by: Journal of Geophysical Research: Space Physics Published on: 07/2019 YEAR: 2019 DOI: 10.1029/2019JA026806 |
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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 the cross-track direction. The two cameras are tilted relative to each other to cover a fan-shaped field of size 130\textdegree \texttimes 10\textdegree. Each camera consists of an unobstructed four-mirror anastigmatic optical system, a BaF2 filter, and a photon-counting imaging detector. The spatial resolution of WAI is ~10 km at the nadir point at a reference height of 110 km above the Earth\textquoterights surface. The sensitivity is \>0.01 counts s-1 Rayleigh-1 pixel-1 (140\textendash180 nm) for both cameras, which is sufficient for mapping the boundaries and the fine structures of the auroral oval during storms/substorms. Based on the tests and calibrations that were conducted prior to launch, the data processing algorithm includes photon signal decoding, geometric distortion correction, photometric correction, flat-field correction, line-of-sight projection and correction, and normalization between the two cameras. Preliminarily processed images are compared with DMSP SSUSI images. The agreement between the images that were captured by two instruments demonstrates that the WAI and the data processing algorithm operate normally and can provide high-quality scientific data for future studies on auroral dynamics. 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; Published by: Light: Science \& Applications Published on: 05/2019 YEAR: 2019 DOI: 10.1038/s41377-019-0157-7 |
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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 the cross-track direction. The two cameras are tilted relative to each other to cover a fan-shaped field of size 130\textdegree \texttimes 10\textdegree. Each camera consists of an unobstructed four-mirror anastigmatic optical system, a BaF2 filter, and a photon-counting imaging detector. The spatial resolution of WAI is ~10 km at the nadir point at a reference height of 110 km above the Earth\textquoterights surface. The sensitivity is \>0.01 counts s-1 Rayleigh-1 pixel-1 (140\textendash180 nm) for both cameras, which is sufficient for mapping the boundaries and the fine structures of the auroral oval during storms/substorms. Based on the tests and calibrations that were conducted prior to launch, the data processing algorithm includes photon signal decoding, geometric distortion correction, photometric correction, flat-field correction, line-of-sight projection and correction, and normalization between the two cameras. Preliminarily processed images are compared with DMSP SSUSI images. The agreement between the images that were captured by two instruments demonstrates that the WAI and the data processing algorithm operate normally and can provide high-quality scientific data for future studies on auroral dynamics. 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; Published by: Light: Science \& Applications Published on: 05/2019 YEAR: 2019 DOI: 10.1038/s41377-019-0157-7 |
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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 onto the magnetotail. If such a hypothesis is correct, it should predict a brighter aurora in the nightside Southern Hemisphere (SH) for positive IMF By than negative IMF By. Here we investigate this hypothesis using Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics/Global Ultraviolet Imager data. The present study not only reproduces the result previously found in NH but also shows an opposite change to its Northern Hemispheric counterpart in SH in response to the different IMF By polarity. When comparing north to south, for negative IMF By, the premidnight auroral energy flux is greater in NH than that in SH. The result becomes opposite for positive IMF By. This result is consistent with the hypothesis of the existence of an interhemispheric field-aligned current. Published by: Journal of Geophysical Research: Space Physics Published on: 02/2019 YEAR: 2019 DOI: 10.1029/2018JA025953 |
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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 longitudinal effect averaged for a fixed local time is greater in the daytime (6\textendash8\textdegree) than in the nighttime (3\textendash5\textdegree). The longitudinal effect magnitude reaches its maximum (16\textdegree) in the morning (at 08 LT) in the Southern hemisphere at high solar activity. But on certain days at any solar activity the longitudinal effect magnitude can reach 9\textendash10\textdegree even at night. The shape of the longitudinal effect was found to differ significantly in two hemispheres. In the Northern hemisphere the trough is usually closest to the pole in the eastern (American) longitudinal sector, and in the Southern hemisphere the trough is closest in the western (Eurasian) longitudinal sector. The magnitude and shape of the longitudinal effect is also different during low and high solar activity. The Global Self-consistent Model of the Thermosphere, Ionosphere, and Protonosphere (GSM TIP) simulations demonstrate that during low solar activity, the longitudinal variations of the daytime trough position is mainly determined by longitudinal variations of the ionization function, formed due to the longitudinal variations in the solar zenith angle and the atomic oxygen density distribution. The longitudinal variations of the nighttime trough position is formed by the longitudinal variations in ionization of precipitating auroral particles, neutral atmosphere composition, and electric field. Karpachev, A.T.; Klimenko, M.V.; Klimenko, V.V.; Published by: Advances in Space Research Published on: 01/2019 YEAR: 2019 DOI: 10.1016/j.asr.2018.09.038 |
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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 longitudinal effect averaged for a fixed local time is greater in the daytime (6\textendash8\textdegree) than in the nighttime (3\textendash5\textdegree). The longitudinal effect magnitude reaches its maximum (16\textdegree) in the morning (at 08 LT) in the Southern hemisphere at high solar activity. But on certain days at any solar activity the longitudinal effect magnitude can reach 9\textendash10\textdegree even at night. The shape of the longitudinal effect was found to differ significantly in two hemispheres. In the Northern hemisphere the trough is usually closest to the pole in the eastern (American) longitudinal sector, and in the Southern hemisphere the trough is closest in the western (Eurasian) longitudinal sector. The magnitude and shape of the longitudinal effect is also different during low and high solar activity. The Global Self-consistent Model of the Thermosphere, Ionosphere, and Protonosphere (GSM TIP) simulations demonstrate that during low solar activity, the longitudinal variations of the daytime trough position is mainly determined by longitudinal variations of the ionization function, formed due to the longitudinal variations in the solar zenith angle and the atomic oxygen density distribution. The longitudinal variations of the nighttime trough position is formed by the longitudinal variations in ionization of precipitating auroral particles, neutral atmosphere composition, and electric field. Karpachev, A.T.; Klimenko, M.V.; Klimenko, V.V.; Published by: Advances in Space Research Published on: 01/2019 YEAR: 2019 DOI: 10.1016/j.asr.2018.09.038 |
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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 physical models, and to provide needed information for space weather customers and researchers. The working team developed a process for validating auroral electrodynamic quantities that begins with the selection of a set of events, followed by construction of ground truth databases using all available data and assimilative data analysis techniques. Using optimized, predefined metrics, the ground truth data for selected events can be used to assess model performance and improvement over time. The availability of global observations and sophisticated data assimilation techniques provides the means to create accurate ground truth databases routinely and accurately. 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; Published by: Space Weather Published on: 01/2019 YEAR: 2019 DOI: 10.1029/2018SW002127 |
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Research Progress on On-Orbit Calibration Technology for Far Ultraviolet Payload Li-ping, Fu; Nan, Jia; Xiu-qing, Hu; Tian, Mao; Fang, Jiang; Yun-gang, Wang; Ru-yi, Peng; Tian-fang, Wang; Da-xin, Wang; Shuang-tuan, Dou; , others; Published by: Published on: |
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Li, Zhenxing; Luan, Xiaoli; Ren, Dexin; Published by: Journal of Geophysical Research: Space Physics Published on: |
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Anomaly distribution of ionospheric total electron content responses to some solar flares Le, Huijun; Liu, Libo; Chen, Yiding; Zhang, Hui; Published by: Earth and Planetary Physics Published on: |
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North-south Asymmetry in Dayside Auroras Associated With Local Sunlight Conditions Mitchell, Elizabeth; Liou, Kan; Published by: Published on: |
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Global-scale Observations of the Equatorial Ionization Anomaly Abstract The National Aeronautics and Space Administration Global-scale Observations of the Limb and Disk ultraviolet spectrograph has been imaging the equatorial ionization anomaly (EIA), regions of the ionosphere with enhanced electron density north and south of the magnetic equator, since October 2018. The initial 3 months of observations was during solar minimum conditions, and they included observations in December solstice of unanticipated variability and depleted regions. Depletions are seen on most nights, in contrast to expectations from previous space-based observations. The variety of scales and morphologies also pose challenges to understanding of the EIA. Abrupt changes in the EIA location, which could be related to in situ measurements of large-scale depletion regions, are observed on some nights. Such synoptic-scale disruptions have not been previously identified. Eastes, R.; Solomon, S.; Daniell, R.; Anderson, D.; Burns, A.; England, S.; Martinis, C.; McClintock, W.; Published by: Geophysical Research Letters Published on: YEAR: 2019 DOI: https://doi.org/10.1029/2019GL084199 Equatorial ionosphere; ionospheric irregularities; ionospheric dynamics; Ionospheric storms; forecasting; airglow and aurora |
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Simulation of ionospheric behavior in the Eastern Asia during magnetic storm on March 17--19, 2015 Based on numerical model of the ionosphere and plasmasphere, we simulated behavior of the ionospheric parameters during the main phase of the 17 March 2015 St. Patrick’s Day Published by: Published on: YEAR: 2019 DOI: 10.1117/12.2540705 |
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On the difference between real-time and research simulations with CTIPe Understanding the thermosphere and ionosphere conditions is crucial for spacecraft operations and many applications using radio signal transmission (e.g. in communication and navigation). In this sense, physics based modelling plays an important role, since it can adequately reproduce the complex coupling mechanisms in the magnetosphere-ionosphere-thermosphere (MIT) system. The accuracy of the physics based model results does not only depend on the appropriate implementation of the physical processes, but also on the quality of the input data (forcing). In this study, we analyze the impact of input data uncertainties on the model results. We use the Coupled Thermosphere Ionosphere Plasmasphere electrodynamics model (CTIPe), which requires satellite based solar wind, interplanetary field and hemispheric power data from ACE and TIROS/NOAA missions. To identify the impact of the forcing uncertainties, two model runs are compared against each other. The first run uses the input data that were available in real-time (operational) and the second run uses the best estimate obtained in post-processing (research or historical run). Fernandez-Gomez, Isabel; Fedrizzi, Mariangel; Codrescu, Mihail; Borries, Claudia; Fillion, Martin; Fuller-Rowell, Timothy; Published by: Advances in Space Research Published on: YEAR: 2019 DOI: 10.1016/j.asr.2019.02.028 |
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Klimenko, MV; Ratovsky, KG; Themens, D; Yasukevich, AS; Klimenko, VV; Published by: Published on: |
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Klimenko, MV; Ratovsky, KG; Themens, D; Yasukevich, AS; Klimenko, VV; Published by: Published on: |
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We use the observations from the incoherent scatter radar and the magnetometers over Jicamarca (11.95 S, 76.87 W) sector to investigate the equatorial ionospheric electrodynamics Zhang, Ruilong; Liu, Libo; Le, Huijun; Chen, Yiding; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2019 DOI: 10.1029/2018JA026295 |
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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 ranging from room temperature to 350\textdegree, then a 20 nm MgF2 film is deposited on the surface of Al/MgF2. The thickness of each layer is characterized using grazing incidence x-ray reflectivity. The reflectivity of sample is measured at the incident angle of 5\textdegree in the wavelength range of 105~130 nm. The reflectivity of all samples fabricated at above room temperature is higher than the sample at room temperature below 115nm. The reflectivity of mirror at 350\textdegree temperature is lower than other mirrors, and the reflectivity of the samples at 300\textdegree and 200\textdegree is similar. There are more black dots on the surface of mirror at 350\textdegree than 300\textdegree, and no black dot on the surface of mirror at 200\textdegree. The measured results using surface profiler show that the black dots are small holes that increase the roughness of mirror and reduce the reflectivity. So the best temperature for depositing the upper MgF2 layer is in 200~300\textdegree to obtain high reflectivity of Al mirrors in vacuum ultraviolet. Wang, Fengli; Li, Shuangying; Zhang, Zhuangzhuang; Wang, Zhanshan; Zhou, Hongjun; Huo, Tonglin; Published by: Published on: YEAR: 2019 DOI: 10.1117/12.2540004 |
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Planetary wave-like oscillations in thermospheric composition Yue, Jia; Lieberman, Ruth; Wang, Wenbin; Jian, Yongxiao; Published by: Published on: |
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Ionosphere-thermosphere system heating and cooling during storms Zesta, Eftyhia; Oliveira, Denny; Zhang, Yongliang; Dawkins, Erin; Panka, Peter; Published by: Published on: |
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SIHlA-Spatial/spectral imaging of hydrogen Lyman alpha Paxton, L; Roelof, E; Lisse, C; Vervack, R; McNutt, R; Provornikova, E; Cox, A; Dyster, J; Gruntman, M; Katushkina, O; , others; Published by: Published on: |
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Park, Jong-Sun; Shi, Quanqi; Nowada, Motoharu; Shue, Jih-Hong; Kim, Khan-Hyuk; Lee, Dong-Hun; Zong, Qiugang; Degeling, Alexander; Tian, Anmin; Pitkänen, Timo; , others; Published by: Published on: |
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Composition Changes Around the Equinoxes Burns, Alan; Cai, Xuguang; Wang, Wenbin; Qian, Liying; Zhang, Yongliang; Eastes, Richard; McClintock, William; Published by: Published on: |
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IMF B y Effects on the high-latitude Ionosphere and Thermosphere Liu, Jing; Wang, Wenbin; Burns, Alan; Zhang, Yongliang; Published by: Published on: |
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Tonolo, Federica; Salmain, Michèle; Scalcon, Valeria; Top, Siden; Pigeon, Pascal; Folda, Alessandra; Caron, Benoit; Mcglinchey, Michael; Toillon, Robert-Alain; Bindoli, Alberto; , others; Published by: ChemMedChem Published on: |
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Tonolo, Federica; Salmain, Michèle; Scalcon, Valeria; Top, Siden; Pigeon, Pascal; Folda, Alessandra; Caron, Benoit; Mcglinchey, Michael; Toillon, Robert-Alain; Bindoli, Alberto; , others; Published by: ChemMedChem Published on: |
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Critical issues in ionospheric data quality and implications for scientific studies Araujo-Pradere, E; Weatherhead, EC; Dandenault, PB; Bilitza, D; Wilkinson, P; Coker, C; Akmaev, R; Beig, G; a, Bure\^sov\; Paxton, LJ; , others; Published by: Radio Science Published on: |
| 2018 |
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Shpynev, B.G.; Zolotukhina, N.A.; Polekh, N.M.; Ratovsky, K.G.; Chernigovskaya, M.A.; Belinskaya, A.Yu.; Stepanov, A.E.; Bychkov, V.V.; Grigorieva, S.A.; Panchenko, V.A.; Korenkova, N.A.; Mielich, J.; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: 11/2018 YEAR: 2018 DOI: 10.1016/j.jastp.2017.10.014 |
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Shpynev, B.G.; Zolotukhina, N.A.; Polekh, N.M.; Ratovsky, K.G.; Chernigovskaya, M.A.; Belinskaya, A.Yu.; Stepanov, A.E.; Bychkov, V.V.; Grigorieva, S.A.; Panchenko, V.A.; Korenkova, N.A.; Mielich, J.; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: 11/2018 YEAR: 2018 DOI: 10.1016/j.jastp.2017.10.014 |
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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 this interhemispheric transition in four longitudinal sectors and at seven heights under low/high solar activity conditions. The results show that during the June solstice the transition of the stronger EIA peak from the winter to the summer hemisphere is earlier in the sectors where the geomagnetic equator is further away from the subsolar point and the geomagnetic field declination is larger, while during the December solstice the longitudinal variations generally show the opposite compared with that in the June solstice. The distance between the geomagnetic equator and subsolar point and the geomagnetic field configuration control the upward/downward plasma movements in the summer/winter hemisphere, leading to the different transition times in different longitudinal sectors. For both solstices, transition times emerge earlier as height increases, which is mainly caused by the larger effective scale height in the summer hemisphere than in the winter hemisphere, resulting in a smaller electron density difference at higher altitudes with a fast transition. Solar activity alters the transition time below 320\ km, whereas it has no evident effect at higher altitudes. Huang, He; Lu, Xian; Liu, Libo; Wang, Wenbin; Li, Qiaoling; Published by: Journal of Geophysical Research: Space Physics Published on: 11/2018 YEAR: 2018 DOI: 10.1029/2018JA026055 |
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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 this interhemispheric transition in four longitudinal sectors and at seven heights under low/high solar activity conditions. The results show that during the June solstice the transition of the stronger EIA peak from the winter to the summer hemisphere is earlier in the sectors where the geomagnetic equator is further away from the subsolar point and the geomagnetic field declination is larger, while during the December solstice the longitudinal variations generally show the opposite compared with that in the June solstice. The distance between the geomagnetic equator and subsolar point and the geomagnetic field configuration control the upward/downward plasma movements in the summer/winter hemisphere, leading to the different transition times in different longitudinal sectors. For both solstices, transition times emerge earlier as height increases, which is mainly caused by the larger effective scale height in the summer hemisphere than in the winter hemisphere, resulting in a smaller electron density difference at higher altitudes with a fast transition. Solar activity alters the transition time below 320\ km, whereas it has no evident effect at higher altitudes. Huang, He; Lu, Xian; Liu, Libo; Wang, Wenbin; Li, Qiaoling; Published by: Journal of Geophysical Research: Space Physics Published on: 11/2018 YEAR: 2018 DOI: 10.1029/2018JA026055 |
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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 of NO chemistry and its relationship to energy deposition in the thermospheric photochemical reactions. In this study, the chemical scheme in the Global Ionosphere Thermosphere Model (GITM) is updated to better predict the lower thermospheric NO responses to solar and geomagnetic activity. We investigate the sensitivity of the 5.3-micron NO emission to F10.7 and Ap indices by comparing the global integrated emission from GITM with an empirical proxy derived from the Sounding of the Atmosphere using Broadband Emission Radiometry measurements. GITM\textquoterights total emission agrees well within 20\% of the empirical values. The updated chemistry scheme significantly elevates the level of integrated emission compared to the previous scheme. The inclusion of N2(A)-related production of NO contributes an additional 5-25\% to the emission. Localized enhancement of ~70\% in column density and a factor of three in column emission are simulated at a moderate geomagnetic level. Lin, Cissi; Deng, Yue; Venkataramani, Karthik; Yonker, Justin; Bailey, Scott; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2018 YEAR: 2018 DOI: 10.1029/2018JA025310 |
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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 solar flares, respectively. The electron density, thermospheric neutral density, and neutral temperature simulated by the Thermosphere-Ionosphere Electrodynamics Global Circulation Model show that the behavior of ionospheric and thermospheric responses is different. The ionospheric disturbances occurred at the altitude ranges of 150-300\ km, and the thermospheric responses occurred at the altitudes of 250-400\ km are caused by solar extreme ultraviolet and ultraviolet photons, respectively. Both ionospheric and thermospheric responses are proportional to the height within their corresponding altitude ranges. Observations and simulations reveal that the ionospheric and thermospheric responses are nonlinearly dependent on the solar zenith angle. The disturbances caused by the X2.2 solar flare are symmetric, but the X9.3 solar flare are not. The O/N2 density ratio simulated by Thermosphere-Ionosphere Electrodynamics Global Circulation Model increases from lev0 to lev5.0 pressure surface with a magnitude of 0.1\textendash1.8, while the ratio decreases in the American sector with a magnitude of -0.6 to -0.3. The longitudinal asymmetry of O/N2 density ratio is a major contributor to the longitudinal asymmetry of ionospheric and thermospheric responses. Li, Wang; Yue, Jianping; Yang, Yang; He, Changyong; Hu, Andong; Zhang, Kefei; Published by: Journal of Geophysical Research: Space Physics Published on: 10/2018 YEAR: 2018 DOI: 10.1029/2018JA025700 |
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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, nighttime temperatures changed earlier than daytime temperatures, and temperatures changed earlier at high latitudes than at low ones. Furthermore, temperatures increased in some places/times and decreased in others. As the simulation behaves similar to observations, it provides an opportunity to understand physical processes that drive the observed changes. Our analysis has shown that they were produced mainly by adiabatic heating/cooling that was associated with vertical winds resulting from general circulation changes, with additional contributions from vertical heat advection. Li, Jingyuan; Wang, Wenbin; Lu, Jianyong; Yuan, Tao; Yue, Jia; Liu, Xiao; Zhang, Kedeng; Burns, Alan; Zhang, Yongliang; Li, Zheng; Published by: Geophysical Research Letters Published on: 08/2019 YEAR: 2018 DOI: 10.1029/2018GL078968 |
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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, nighttime temperatures changed earlier than daytime temperatures, and temperatures changed earlier at high latitudes than at low ones. Furthermore, temperatures increased in some places/times and decreased in others. As the simulation behaves similar to observations, it provides an opportunity to understand physical processes that drive the observed changes. Our analysis has shown that they were produced mainly by adiabatic heating/cooling that was associated with vertical winds resulting from general circulation changes, with additional contributions from vertical heat advection. Li, Jingyuan; Wang, Wenbin; Lu, Jianyong; Yuan, Tao; Yue, Jia; Liu, Xiao; Zhang, Kedeng; Burns, Alan; Zhang, Yongliang; Li, Zheng; Published by: Geophysical Research Letters Published on: 08/2019 YEAR: 2018 DOI: 10.1029/2018GL078968 |
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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, nighttime temperatures changed earlier than daytime temperatures, and temperatures changed earlier at high latitudes than at low ones. Furthermore, temperatures increased in some places/times and decreased in others. As the simulation behaves similar to observations, it provides an opportunity to understand physical processes that drive the observed changes. Our analysis has shown that they were produced mainly by adiabatic heating/cooling that was associated with vertical winds resulting from general circulation changes, with additional contributions from vertical heat advection. Li, Jingyuan; Wang, Wenbin; Lu, Jianyong; Yuan, Tao; Yue, Jia; Liu, Xiao; Zhang, Kedeng; Burns, Alan; Zhang, Yongliang; Li, Zheng; Published by: Geophysical Research Letters Published on: 08/2019 YEAR: 2018 DOI: 10.1029/2018GL078968 |
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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 molecular nitrogen (O/N2) in the thermosphere.To interpret the observed disturbances in the upper atmosphere, the ex-perimental measurements are compared with the results of model calculations obtained with the Global Self-Consistent Model of Thermosphere\textemdashIonosphere\textemdashProtonosphere (GSM TIP). The response of the upper atmosphere to the SSW event is shown to be a decreasein foF2 and TEC during the evolution of the warming event and a prolonged increase in O/N2, foF2, and TEC after the SSW maximum. For the first time, we observe the relation between the increase in stratospheric ozone, thermospheric O/N2, and ionospheric electron densityfor a fairly long time (up to 20 days) after the SSW maximum at midlatitudes. 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; Published by: Solnechno-Zemnaya Fizika Published on: 08/2018 YEAR: 2018 DOI: 10.12737/issue_5c1b83b913d443.7589563310.12737/szf-44201807 |
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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 molecular nitrogen (O/N2) in the thermosphere.To interpret the observed disturbances in the upper atmosphere, the ex-perimental measurements are compared with the results of model calculations obtained with the Global Self-Consistent Model of Thermosphere\textemdashIonosphere\textemdashProtonosphere (GSM TIP). The response of the upper atmosphere to the SSW event is shown to be a decreasein foF2 and TEC during the evolution of the warming event and a prolonged increase in O/N2, foF2, and TEC after the SSW maximum. For the first time, we observe the relation between the increase in stratospheric ozone, thermospheric O/N2, and ionospheric electron densityfor a fairly long time (up to 20 days) after the SSW maximum at midlatitudes. 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; Published by: Solnechno-Zemnaya Fizika Published on: 08/2018 YEAR: 2018 DOI: 10.12737/issue_5c1b83b913d443.7589563310.12737/szf-44201807 |
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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 molecular nitrogen (O/N2) in the thermosphere.To interpret the observed disturbances in the upper atmosphere, the ex-perimental measurements are compared with the results of model calculations obtained with the Global Self-Consistent Model of Thermosphere\textemdashIonosphere\textemdashProtonosphere (GSM TIP). The response of the upper atmosphere to the SSW event is shown to be a decreasein foF2 and TEC during the evolution of the warming event and a prolonged increase in O/N2, foF2, and TEC after the SSW maximum. For the first time, we observe the relation between the increase in stratospheric ozone, thermospheric O/N2, and ionospheric electron densityfor a fairly long time (up to 20 days) after the SSW maximum at midlatitudes. 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; Published by: Solnechno-Zemnaya Fizika Published on: 08/2018 YEAR: 2018 DOI: 10.12737/issue_5c1b83b913d443.7589563310.12737/szf-44201807 |
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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 enhancements are well confined between \textpm30\textdegree and \textpm50\textdegree magnetic latitude, with the magnetic flux tubes of L = 1.3 - 2.4 connecting to the plasmasphere. Furthermore, coincident longitudinal variations exist in both the ionospheric enhancements and the plasmaspheric total electron content, especially during the solstice months. The coincidence may suggest essential plasma transport between the ionosphere and the plasmasphere. These facts support the idea that the plasmasphere provides extra plasma to the midlatitude ionosphere through downward plasma influx along the magnetic field lines to form the nighttime ionization enhancements when the sunlight is absent. Li, Quanhan; Hao, Yongqiang; Zhang, Donghe; Xiao, Zuo; Published by: Journal of Geophysical Research: Space Physics Published on: 08/2018 YEAR: 2018 DOI: 10.1029/2018JA025422 |
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Wang, Jack; Tsai-Lin, Rong; Chang, Loren; Wu, Qian; Lin, Charles; Yue, Jia; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: 06/2018 YEAR: 2018 DOI: 10.1016/j.jastp.2017.07.024 |
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Wang, Jack; Tsai-Lin, Rong; Chang, Loren; Wu, Qian; Lin, Charles; Yue, Jia; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: 06/2018 YEAR: 2018 DOI: 10.1016/j.jastp.2017.07.024 |