Bibliography
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Found 41 entries in the Bibliography.
Showing entries from 1 through 41
| 2022 |
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Neutral composition information in ICON EUV dayglow observations Since the earliest space‐based observations of Earth s atmosphere, ultraviolet (UV) airglow has proven a useful resource for remote sensing of the ionosphere and thermosphere. The Tuminello, Richard; England, Scott; Sirk, Martin; Meier, Robert; Stephan, Andrew; Korpela, Eric; Immel, Thomas; Mende, Stephen; Frey, Harald; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2022 DOI: 10.1029/2022JA030592 |
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Time Delay Integration Imaging of the Nighttime Ionosphere from the ICON Observatory TIMED GUVI was on a high inclination orbit changing local time relatively slowly and missing a great deal of the equatorward low latitude regions at the wrong local times. Mende, SB; Frey, HU; England, SL; Immel, TJ; Eastes, RW; Published by: Space Science Reviews Published on: YEAR: 2022 DOI: 10.1007/s11214-022-00928-w |
| 2021 |
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In near-Earth space, variations in thermospheric composition have important implications for thermosphere-ionosphere coupling. The ratio of O to N2 is often measured using far-UV airglow observations. Taking such airglow observations from space, looking below the Earth s limb allows for the total column of O and N2 in the ionosphere to be determined. While these observations have enabled many previous studies, determining the impact of nonmigrating tides on thermospheric composition has proved difficult, owing to a small contamination of the signal by recombination of ionospheric O+. New ICON observations of far-UV are presented here, and their general characteristics are shown. Using these, along with other observations and a global circulation model, we show that during the morning hours and at latitudes away from the peak of the equatorial ionospheric anomaly, the impact of nonmigrating tides on thermospheric composition can be observed. During March–April 2020, the column O/N2 ratio was seen to vary by 3–4\% of the zonal mean. By comparing the amplitude of the variation observed with that in the model, both the utility of these observations and a pathway to enable future studies is shown. England, Scott; Meier, R.; Frey, Harald; Mende, Stephen; Stephan, Andrew; Krier, Christopher; Cullens, Chihoko; Wu, Yen-Jung; Triplett, Colin; Sirk, Martin; Korpela, Eric; Harding, Brian; Englert, Christoph; Immel, Thomas; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2021 DOI: 10.1029/2021JA029575 airglow; atmospheric composition; Atmospheric tides; thermosphere |
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Conjugate Photoelectron Energy Spectra Derived From Coincident FUV and Radio Measurements We present a method for estimating incident photoelectrons energy spectra as a function of altitude by combining global scale far-ultraviolet (FUV) and radio-occultation (RO) measurements. This characterization provides timely insights important for accurate interpretation of ionospheric parameters inferred from the recently launched Ionospheric Connection Explorer (ICON) observations. Quantification of photoelectron impact is enabled by the fact that conjugate photoelectrons (CPEs) directly affect FUV airglow emissions but not RO measurements. We demonstrate a technique for estimation of photoelectron fluxes and their spectra by combining coincident ICON and COSMIC2 measurements and show that a significant fraction of ICON-FUV measurements is affected by CPEs during the winter solstice. A comparison of estimated photoelectron fluxes with measured photoelectron spectra is used to gain further insights into the estimation method and reveals consistent values within 10–60 eV. Urco, J.; Kamalabadi, F.; Kamaci, U.; Harding, B.; Frey, H.; Mende, S.; Huba, J.; England, S.; Immel, T.; Published by: Geophysical Research Letters Published on: YEAR: 2021 DOI: 10.1029/2021GL095839 airglow; conjugate photolectrons; COSMIC2; energy spectra; ICON |
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The global-scale observations of the limb and disk (GOLD) Mission images middle thermosphere temperature and the vertical column density ratio of oxygen to molecular nitrogen (O/N2) using its far ultraviolet imaging spectrographs in geostationary orbit. Since GOLD only measures these quantities during daylight, and only over the ∼140° of longitude visible from geostationary orbit, previously developed tidal analysis techniques cannot be applied to the GOLD data set. This paper presents a novel approach that deduces two specified non-migrating diurnal tides using simultaneous measurements of temperature and O/N2. DE3 (diurnal eastward propagating wave 3) and DE2 (diurnal eastward propagating wave 2) during October 2018 and January 2020 are the focus of this paper. Sensitivity analyses using TIE-GCM simulations reveal that our approach reliably retrieves the true phases, whereas a combination of residual contributions from secondary tides, the restriction in longitude, and random uncertainty can lead to ∼50\% error in the retrieved amplitudes. Application of our approach to GOLD data during these time periods provides the first observations of non-migrating diurnal tides in measurements taken from geostationary orbit. We identify discrepancies between GOLD observations and TIE-GCM modeling. Retrieved tidal amplitudes from GOLD observations exceed their respective TIE-GCM amplitudes by a factor of two in some cases. Krier, Christopher; England, Scott; Greer, Katelynn; Evans, Scott; Burns, Alan; Eastes, Richard; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2021 DOI: 10.1029/2021JA029563 |
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Traveling ionospheric disturbances (TIDs) and their neutral counterparts known as traveling atmospheric disturbances (TADs) are believed to play a role in communicating inputs to other locations in the fluid. While these two phenomena are believed to be connected, they may not have a one-to-one correspondence as the geomagnetic field influences the TID but has no direct impact on the TAD. The relative amplitudes of the perturbations seen in the ionosphere and atmosphere have been observed but rarely together. This study reports results from a 3-day campaign to observe TIDs and TADs simultaneously over a broad latitudinal region over the eastern United States using a combination of Global-scale Observations of the Limb and Disk (GOLD) and a distributed network of ground-based Global Navigation Satellite System (GNSS) receivers. These results demonstrate that GOLD and the ground-based total electron content (TEC) observations can see the atmospheric and ionospheric portions of a large-scale traveling disturbance. The phase difference in the perturbations to the GOLD airglow brightness, O/N2 and thermospheric disk temperature are consistent with an atmospheric gravity wave moving through this region. The ionospheric signatures move at the same rate as those in the atmosphere, but their amplitudes do not have a simple correspondence to the amplitude of the signal seen in the atmosphere. This campaign demonstrates a proof-of-concept that this combination of observations is able to provide information on TIDs and TADs, including quantifying their impact on the temperature and chemical composition of the upper atmosphere. England, Scott; Greer, Katelynn; Zhang, Shun-Rong; Evans, Scott; Solomon, Stanley; Eastes, Richard; McClintock, William; Burns, Alan; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2021 DOI: 10.1029/2021JA029248 |
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A Synoptic-Scale Wavelike Structure in the Nighttime Equatorial Ionization Anomaly Both ground- and satellite-based airglow imaging have significantly contributed to understanding the low-latitude ionosphere, especially the morphology and dynamics of the equatorial ionization anomaly (EIA). The NASA Global-scale Observations of the Limb and Disk (GOLD) mission focuses on far-ultraviolet airglow images from a geostationary orbit at 47.5°W. This region is of particular interest at low magnetic latitudes because of the high magnetic declination (i.e., about -20°) and proximity of the South Atlantic magnetic anomaly. In this study, we characterize an exciting feature of the nighttime EIA using GOLD observations from October 5, 2018 to June 30, 2020. It consists of a wavelike structure of a few thousand kilometers seen as poleward and equatorward displacements of the EIA-crests. Initial analyses show that the synoptic-scale structure is symmetric about the dip equator and appears nearly stationary with time over the night. In quasi-dipole coordinates, maxima poleward displacements of the EIA-crests are seen at about ± 12° latitude and around 20 and 60° longitude (i.e., in geographic longitude at the dip equator, about 53°W and 14°W). The wavelike structure presents typical zonal wavelengths of about 6.7 × 103 km and 3.3 × 103 km. The structure s occurrence and wavelength are highly variable on a day-to-day basis with no apparent dependence on geomagnetic activity. In addition, a cluster or quasi-periodic wave train of equatorial plasma depletions (EPDs) is often detected within the synoptic-scale structure. We further outline the difference in observing these EPDs from FUV images and in situ measurements during a GOLD and Swarm mission conjunction. Rodríguez-Zuluaga, J.; Stolle, C.; Yamazaki, Y.; Xiong, C.; England, S.; Published by: Earth and Space Science Published on: YEAR: 2021 DOI: 10.1029/2020EA001529 equatorial plasma bubbles; Equatorial ionization anomaly; Equatorial ionosphere; forcing from below; wave structure |
| 2020 |
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Karan, Deepak; Daniell, Robert; England, Scott; Martinis, Carlos; Eastes, Richard; Burns, Alan; McClintock, William; Published by: Journal of Geophysical Research: Space Physics Published on: |
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A mesoscale wave-like structure in the nighttime equatorial ionization anomaly Both ground-and satellite-based airglow imaging have significantly contributed to our understanding of the low-latitude ionosphere, especially of the morphology and dynamics of the iguez-Zuluaga, Juan; Stolle, Claudia; Yamazaki, Yosuke; Xiong, Chao; England, Scott; Published by: Earth and Space Science Open Archive ESSOAr Published on: YEAR: 2020 DOI: 10.1002/essoar.10504705.1 |
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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 |
| 2019 |
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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 |
| 2018 |
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Daytime O/N2 Retrieval Algorithm for the Ionospheric Connection Explorer (ICON) The NASA Ionospheric Connection Explorer Far-Ultraviolet spectrometer, ICON FUV, will measure altitude profiles of the daytime far-ultraviolet (FUV) OI 135.6 nm and N2 Lyman-Birge-Hopfield (LBH) band emissions that are used to determine thermospheric density profiles and state parameters related to thermospheric composition; specifically the thermospheric column O/N2 ratio (symbolized as ΣO/N2). This paper describes the algorithm concept that has been adapted and updated from one previously applied with success to limb data from the Global Ultraviolet Imager (GUVI) on the NASA Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission. We also describe the requirements that are imposed on the ICON FUV to measure ΣO/N2 over any 500-km sample in daytime with a precision of better than 8.7\%. We present results from orbit-simulation testing that demonstrates that the ICON FUV and our thermospheric composition retrieval algorithm can meet these requirements and provide the measurements necessary to address ICON science objectives. Stephan, Andrew; Meier, R.; England, Scott; Mende, Stephen; Frey, Harald; Immel, Thomas; Published by: Space Science Reviews Published on: 01/2018 YEAR: 2018 DOI: 10.1007/s11214-018-0477-6 |
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Global-scale Observations of the Limb and Disk (GOLD): science implementation McClintock, William; Eastes, Richard; Andersson, Laila; Burns, Alan; Codrescu, Mihail; Daniell, Robert; England, Scott; Evans, Scott; Krywonos, Andrey; Lumpe, Jerry; , others; Published by: Published on: |
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The NASA Global‐scale Observations of Limb and Disk (GOLD) mission will study the coupling of the thermosphere with the lower atmosphere through an examination of temperature Greer, KR; England, SL; Becker, E; Rusch, D; Eastes, R; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2018 DOI: 10.1029/2018JA025501 |
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The ionospheric connection explorer mission: Mission goals and design The Ionospheric Connection Explorer, or ICON, is a new NASA Explorer mission that will explore the boundary between Earth and space to understand the physical connection Immel, Thomas; England, SL; Mende, SB; Heelis, RA; Englert, CR; Edelstein, J; Frey, HU; Korpela, EJ; Taylor, ER; Craig, WW; , others; Published by: Space Science Reviews Published on: YEAR: 2018 DOI: 10.1007/s11214-017-0449-2 |
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The Ionospheric Connection Explorer (ICON) Far Ultraviolet (FUV) imager, ICON FUV, will measure altitude profiles of OI 135.6 nm emissions to infer nighttime ionospheric parameters. Kamalabadi, Farzad; Qin, Jianqi; Harding, Brian; Iliou, Dimitrios; Makela, Jonathan; Meier, RR; England, Scott; Frey, Harald; Mende, Stephen; Immel, Thomas; Published by: Space science reviews Published on: |
| 2017 |
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Daytime Ionosphere Retrieval Algorithm for the Ionospheric Connection Explorer (ICON) The NASA Ionospheric Connection Explorer Extreme Ultraviolet spectrograph, ICON EUV, will measure altitude profiles of the daytime extreme-ultraviolet (EUV) OII emission near 83.4 and 61.7\ nm that are used to determine density profiles and state parameters of the ionosphere. This paper describes the algorithm concept and approach to inverting these measured OII emission profiles to derive the associated O+ density profile from 150\textendash450\ km as a proxy for the electron content in the F-region of the ionosphere. The algorithm incorporates a bias evaluation and feedback step, developed at the U.S. Naval Research Laboratory using data from the Special Sensor Ultraviolet Limb Imager (SSULI) and the Remote Atmospheric and Ionospheric Detection System (RAIDS) missions, that is able to effectively mitigate the effects of systematic instrument calibration errors and inaccuracies in the original photon source within the forward model. Results are presented from end-to-end simulations that convolved simulated airglow profiles with the expected instrument measurement response to produce profiles that were inverted with the algorithm to return data products for comparison to truth. Simulations of measurements over a representative ICON orbit show the algorithm is able to reproduce hmF2 values to better than 5\ km accuracy, and NmF2 to better than 12\% accuracy over a 12-second integration, and demonstrate that the ICON EUV instrument and daytime ionosphere algorithm can meet the ICON science objectives which require 20\ km vertical resolution in hmF2 and 18\% precision in NmF2. Stephan, Andrew; Korpela, Eric; Sirk, Martin; England, Scott; Immel, Thomas; Published by: Space Science Reviews Published on: 10/2017 YEAR: 2017 DOI: 10.1007/s11214-017-0385-1 |
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The Far Ultra-Violet Imager on the Icon Mission ICON Far UltraViolet (FUV) imager contributes to the ICON science objectives by providing remote sensing measurements of the daytime and nighttime atmosphere/ionosphere. During sunlit atmospheric conditions, ICON FUV images the limb altitude profile in the shortwave (SW) band at 135.6 nm and the longwave (LW) band at 157 nm perpendicular to the satellite motion to retrieve the atmospheric O/N2 ratio. In conditions of atmospheric darkness, ICON FUV measures the 135.6 nm recombination emission of O+ ions used to compute the nighttime ionospheric altitude distribution. ICON Far UltraViolet (FUV) imager is a Czerny\textendashTurner design Spectrographic Imager with two exit slits and corresponding back imager cameras that produce two independent images in separate wavelength bands on two detectors. All observations will be processed as limb altitude profiles. In addition, the ionospheric 135.6 nm data will be processed as longitude and latitude spatial maps to obtain images of ion distributions around regions of equatorial spread F. The ICON FUV optic axis is pointed 20 degrees below local horizontal and has a steering mirror that allows the field of view to be steered up to 30 degrees forward and aft, to keep the local magnetic meridian in the field of view. The detectors are micro channel plate (MCP) intensified FUV tubes with the phosphor fiber-optically coupled to Charge Coupled Devices (CCDs). The dual stack MCP-s amplify the photoelectron signals to overcome the CCD noise and the rapidly scanned frames are co-added to digitally create 12-second integrated images. Digital on-board signal processing is used to compensate for geometric distortion and satellite motion and to achieve data compression. The instrument was originally aligned in visible light by using a special grating and visible cameras. Final alignment, functional and environmental testing and calibration were performed in a large vacuum chamber with a UV source. The test and calibration program showed that ICON FUV meets its design requirements and is ready to be launched on the ICON spacecraft. Mende, S.; Frey, H.; Rider, K.; Chou, C.; Harris, S.; Siegmund, O.; England, S.; Wilkins, C.; Craig, W.; Immel, T.; Turin, P.; Darling, N.; Loicq, J.; Blain, P.; Syrstad, E.; Thompson, B.; Burt, R.; Champagne, J.; Sevilla, P.; Ellis, S.; Published by: Space Science Reviews Published on: 10/2017 YEAR: 2017 DOI: 10.1007/s11214-017-0386-0 |
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The Global-Scale Observations of the Limb and Disk (GOLD) Mission The Earth\textquoterights thermosphere and ionosphere constitute a dynamic system that varies daily in response to energy inputs from above and from below. This system can exhibit a significant response within an hour to changes in those inputs, as plasma and fluid processes compete to control its temperature, composition, and structure. Within this system, short wavelength solar radiation and charged particles from the magnetosphere deposit energy, and waves propagating from the lower atmosphere dissipate. Understanding the global-scale response of the thermosphere-ionosphere (T-I) system to these drivers is essential to advancing our physical understanding of coupling between the space environment and the Earth\textquoterights atmosphere. Previous missions have successfully determined how the \textquotedblleftclimate\textquotedblright of the T-I system responds. The Global-scale Observations of the Limb and Disk (GOLD) mission will determine how the \textquotedblleftweather\textquotedblright of the T-I responds, taking the next step in understanding the coupling between the space environment and the Earth\textquoterights atmosphere. Operating in geostationary orbit, the GOLD imaging spectrograph will measure the Earth\textquoterights emissions from 132 to 162 nm. These measurements will be used image two critical variables\textemdashthermospheric temperature and composition, near 160 km\textemdashon the dayside disk at half-hour time scales. At night they will be used to image the evolution of the low latitude ionosphere in the same regions that were observed earlier during the day. Due to the geostationary orbit being used the mission observes the same hemisphere repeatedly, allowing the unambiguous separation of spatial and temporal variability over the Americas. Eastes, R.; McClintock, W.; Burns, A.; Anderson, D.; Andersson, L.; Codrescu, M.; Correira, J.; Daniell, R.; England, S.; Evans, J.; Harvey, J.; Krywonos, A.; Lumpe, J.; Richmond, A.; Rusch, D.; Siegmund, O.; Solomon, S.; Strickland, D.; Woods, T.; Aksnes, A.; Budzien, S.; Dymond, K.; Eparvier, F.; Martinis, C.; Oberheide, J.; Published by: Space Science Reviews Published on: 10/2017 YEAR: 2017 DOI: 10.1007/s11214-017-0392-2 |
| 2015 |
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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\textendashionosphere\textendashthermosphere system. Dramatic changes in the ionosphere are seen at every one of the active radar stations, extending from Greenland down to equatorial Peru in the American sector and at middle latitudes in Ukraine. Data from TIMED and THEMIS are shown to support initial interpretations of the observations, where we focus on processes in the middle latitude afternoon sector during main phase, and the formation of a dense equatorial ionosphere during storm recovery. The combined measurements strongly suggest that the changes in ionospheric conditions observed after the main storm phase can be attributed in large part to changes in the stormtime thermosphere. This is through the generation of disturbance dynamo winds and also global neutral composition changes that either reduce or enhance plasma densities in a manner that depends mainly upon latitude. Unlike larger storms with possibly more sustained forcing, this storm exhibits minimal effects of persistent meridional stormtime wind drag, and little penetration of solar wind electric potentials to low latitudes. It is, therefore, an outstanding example of an impulsive event that exhibits longer-term effects through modification of the background atmosphere. Immel, Thomas; Liu, Guiping; England, Scott; Goncharenko, Larisa; Erickson, Philip; Lyashenko, Mykhaylo; Milla, Marco; Chau, Jorge; Frey, Harald; Mende, Stephen; Zhou, Qihou; Stromme, Anja; Paxton, Larry; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: 11/2015 YEAR: 2015 DOI: 10.1016/j.jastp.2015.09.005 |
| 2013 |
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Impacts of atmospheric ultrafast Kelvin waves on radio scintillations in the equatorial ionosphere We present a statistical analysis of the amplitudes of GPS scintillations (S4 index) observed throughout 2008\textendash2010 using the satellite radio occultation measurements of the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC). Here, for the first time, periodic variability in the occurrence of S4 is investigated using these data. Significant variations of S4 with periods of 2.5\textendash4 days (quasi-3 days) are identified from the observations during postsunset hours (1900\textendash2400 local time) between 15\textdegreeS\textendash 15\textdegreeN magnetic latitude during this 3 year interval. Coherence analyses of these variations with the geomagnetic Ap index, solar EUV irradiance, and atmospheric wind measurements from an equatorial mesosphere meteor radar at Thumba, India ( 8.5\textdegreeN, 77\textdegreeE) are performed, providing a measure of the relationship between variations in the scintillations and potential drivers. The quasi-3 day variations in S4 are found to covary with the variations of the three drivers examined. In particular, the S4 signatures are found to be coherent with the atmospheric ultrafast Kelvin (UFK) planetary waves characterized by the zonal wind measurements of the radar. This study shows that these UFK waves are as important as the solar and geomagnetic drivers in forcing the day-to-day variations of the occurrence of equatorial spread F. Liu, Guiping; Immel, Thomas; England, Scott; Frey, Harald; Mende, Stephen; Kumar, Karanam; Ramkumar, Geetha; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2013 YEAR: 2013 DOI: 10.1002/jgra.50139 day-to-day variability; Equatorial ionosphere; scintillation; Ultra Fast Kelvin planetary wave |
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The GOLD Science Data Center-Algorithm Heritage, Data Product Descriptions and User Services Lumpe, JD; Foroosh, H; Eastes, R; Krywonos, A; Evans, JS; Burns, AG; Strickland, DJ; Daniell, RE; England, S; Solomon, SC; , others; Published by: Published on: |
| 2012 |
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An empirical model of the drift velocity of equatorial plasma depletions The Far-Ultraviolet Imager on the IMAGE spacecraft (IMAGE-FUV) has been used to observe O+plasma depletions in the post-sunset equatorial ionosphere. Small-scale density irregularities associated with such depletions are believed to adversely affect trans-ionospheric radio signals such as GPS. Prediction of the motion of these plasma depletions is a necessary component of the ability to forecast the occurrence of such radio signal interference. An automated method has recently been developed to identify and track the position and zonal drift velocity of these depletions. Here we use this method to create a large database of the zonal drift velocities of these depletions. We present an empirical model based on these observations that describes the observed drift velocities as a function of both local time and magnetic latitude, which is essential to represent their behavior. A comparison of the observed drift velocities with zonal winds from both an empirical model (Horizontal Wind Model; HWM07) and a first-principles model (the TIEGCM) reveals that the plasma depletions\textquoteright drift velocities have a latitudinal gradient that cannot be explained solely by the F-region dynamo in the post-sunset period, at least by these climatological models. This suggests that these plasma depletions may not simply drift with the background F-region plasma. It has previously been suggested that vertical polarization electric fields associated with the plasma depletions are responsible for their zonal drifts exceeding the background flow, which may explain the previously-observed discrepancy in the drift velocities and the discrepancy in their gradients reported here. Published by: Journal of Geophysical Research: Space Physics Published on: 12/2012 YEAR: 2012 DOI: 10.1029/2012JA018091 |
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Solar thermal tides are planetary-scale waves in the neutral atmosphere with periods that are harmonics of 24\ hours. In the thermosphere, they can achieve significant amplitude and can be the dominant source of variation in the atmosphere. Through their modification of the neutral atmosphere, they can also significantly modify the ionosphere, especially at low-latitudes where the dynamics of the Earth\textquoterights ionosphere is determined to a large extent by the neutral atmosphere. Much recent work has focused on characterizing and understanding the impact of one sub-group of tides, known as non-migrating tides, on the ionosphere. Whereas migrating tides are responsible for creating strong day-night variations in the ionosphere, non-migrating tides create longitudinal variations in the ionosphere, the signature of which can only be detected with distributed networks of ground-based observations or spacecraft. The present work reviews the recent observations and modeling efforts that have helped to characterize and explain this longitudinal variability. Emphasis is placed on the characteristics of tides throughout the thermosphere, their impacts on the chemical composition of the thermosphere, and impacts on the ionosphere. Published by: Space Science Reviews Published on: 06/2012 YEAR: 2012 DOI: 10.1007/s11214-011-9842-4 |
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A review of the effects of non-migrating atmospheric tides on the Earth’s low-latitude ionosphere Published by: Space science reviews Published on: |
| 2010 |
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Thermospheric composition variations due to nonmigrating tides and their effect on ionosphere Zhang, Yongliang; England, Scott; Paxton, L.; Published by: Geophysical Research Letters Published on: Jan-09-2010 YEAR: 2010 DOI: 10.1029/2010GL044313 |
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England, S.; Immel, T.; Huba, J.; Hagan, M.; Maute, A.; DeMajistre, R.; Published by: Journal of Geophysical Research Published on: Jan-01-2010 YEAR: 2010 DOI: 10.1029/2009JA014894 |
| 2009 |
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Three-dimensional equatorial spread F modeling: Zonal neutral wind effects Huba, J.; Ossakow, S.; Joyce, G.; Krall, J.; England, S.; Published by: Geophysical Research Letters Published on: Jan-01-2009 YEAR: 2009 DOI: 10.1029/2009GL040284 |
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England, Scott; Zhang, Xiaoli; Immel, Thomas; Forbes, Jeffrey; DeMajistre, Robert; Published by: Earth Planets Space Published on: |
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Upward propagating tidal effects across the E-and F-regions of the ionosphere Immel, Thomas; England, Scott; Zhang, Xiaoli; Forbes, Jeffrey; DeMajistre, Robert; Published by: Earth, planets and space Published on: |
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Three-dimensional equatorial spread F modeling: Zonal neutral wind effect Joyce, GR; Huba, J; Ossakow, SL; Krall, J; England, S; Published by: Published on: |
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Three-dimensional equatorial spread F modeling: Zonal neutral wind effects Huba, JD; Ossakow, SL; Joyce, G; Krall, J; England, SL; Published by: Geophysical Research Letters Published on: |
| 2008 |
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Wave structures of the plasma density and vertical E$\times$ B drift in low-latitude F region We investigate the seasonal, longitudinal, local time (LT), and altitudinal variations of the F region morphology at low latitudes using data from the first Republic of China satellite (ROCSAT-1), Global Ultraviolet Imager (GUVI), on board the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite, and the Defense Meteorological Satellite Program (DMSP) F13 and F15 satellites. Signatures of the longitudinally periodic plasma density structure emerge before 0900 LT. The wave structure is established before noon and further amplified in the afternoon. The amplitudes of the wave structure start to diminish in the evening. The wave-4 structure is clearly distinguishable during equinox and northern hemisphere summer. During northern hemisphere winter, the density structure can be characterized to either wave-4 or wave-3 structure owing to marginal separation of the two peaks in 180°–300°E. Observations of similar density structures from ROCSAT-1 (600 km) and DMSP (840 km) at 0930 and 1800 LT indicate the extension of the wave structure to altitudes greater than 840 km. The daytime wave structure persists into the night during the equinoxes but is significantly modified during the solstices. The modification is more significant at higher altitudes and is attributed to the effects of interhemispheric winds and the prereversal enhancement. The formation of the wavelike density structure in the morning and its temporal evolution in the afternoon show a close association with the vertical E × B drift. We conclude that the E × B drift during 0900–1200 LT determines the formation of the wavelike density structure. Kil, H.; Talaat, E.; Oh, S.-J.; Paxton, L.; England, S.; Su, S.-Y.; Published by: Journal of Geophysical Research Published on: Jan-01-2008 YEAR: 2008 DOI: 10.1029/2008JA013106 |
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Eastes, R; Burns, AG; McClintock, W; Aksnes, A; Anderson, D; Andersson, L; Budzien, S; Codrescu, M; Daniell, R; England, S; , others; Published by: Published on: |
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Wave structures of the plasma density and vertical E$\times$ B drift in low-latitude F region Kil, H; Talaat, ER; Oh, S-J; Paxton, LJ; England, SL; Su, S-Y; Published by: Journal of Geophysical Research: Space Physics Published on: |
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England, SL; Immel, TJ; Huba, JD; Published by: Journal of Geophysical Research: Space Physics Published on: |
| 2007 |
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Longitudinal structure of the vertical E$\times$ B drift and ion density seen from ROCSAT-1 Kil, Hyosub; Oh, S-J; Kelley, MC; Paxton, LJ; England, SL; Talaat, E; Min, K-W; Su, S-Y; Published by: Geophysical Research Letters Published on: |
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Park, SH; England, SL; Immel, TJ; Frey, HU; Mende, SB; Published by: Journal of Geophysical Research: Space Physics Published on: |
| 2006 |
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England, S.; Immel, T.; Sagawa, E.; Henderson, S.; Hagan, M.; Mende, S.; Frey, H.; Swenson, C.; Paxton, L.; Published by: Journal of Geophysical Research Published on: Jan-01-2006 YEAR: 2006 DOI: 10.1029/2006JA011795 |
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Longitudinal variation of the E-region electric fields caused by atmospheric tides England, S.; Maus, S.; Immel, T.; Mende, S.; Published by: Geophysical Research Letters Published on: Jan-01-2006 YEAR: 2006 DOI: 10.1029/2006GL027465 |
| 2005 |
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England, SL; Immel, TJ; Sagawa, E; Henderson, S; Hagan, ME; Mende, SB; Frey, HU; Swenson, C; Paxton, LJ; Published by: Published on: |
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