Bibliography

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

\textlessp\textgreater\textlessstrong class="journal-contentHeaderColor"\textgreaterAbstract.\textless/strong\textgreater We present a method for augmenting spacecraft measurements of thermospheric composition with quantitative estimates of daytime thermospheric composition below 200 \textlessspan class="inline-formula"\textgreaterkm\textless/span\textgreater, inferred from ionospheric data, for which there is a global network of ground-based stations. 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. 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 transition region between F1 and F2 peaks can be expressed by the “\textlessspan class="inline-formula"\textgreater\textitG\textless/span\textgreater” factor, a function of ion production rate and loss rates via ion–atom interchange reactions and dissociative recombination of molecular ions. This in turn can be expressed as the square of the ratio of ions lost via these processes. We compare estimates of the \textlessspan class="inline-formula"\textgreater\textitG\textless/span\textgreater factor obtained from ionograms recorded at Kwajalein (9\textlessspan class="inline-formula"\textgreater$^\textrm∘$\textless/span\textgreater N, 167.2\textlessspan class="inline-formula"\textgreater$^\textrm∘$\textless/span\textgreater E) for 25 times during which the Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) spacecraft recorded approximately co-located measurements of the neutral thermosphere. We find a linear relationship between \textlessspan class="inline-formula"\textgreater\textlessmath xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"\textgreater\textlessmsqrt\textgreater\textlessmi\textgreaterG\textless/mi\textgreater\textless/msqrt\textgreater\textless/math\textgreater\textlessspan\textgreater\textlesssvg:svg xmlns:svg="http://www.w3.org/2000/svg" width="21pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="fe020e378fd223a5491b91deb815e309"\textgreater\textlesssvg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="angeo-39-309-2021-ie00001.svg" width="21pt" height="12pt" src="angeo-39-309-2021-ie00001.png"/\textgreater\textless/svg:svg\textgreater\textless/span\textgreater\textless/span\textgreater and the molecular-to-atomic composition ratio, with a gradient of \textlessspan class="inline-formula"\textgreater2.55±0.40\textless/span\textgreater. Alternatively, using hmF1 values obtained by ionogram inversion, this gradient was found to be \textlessspan class="inline-formula"\textgreater4.75±0.4\textless/span\textgreater. Further, accounting for equal ionisation in molecular and atomic species yielded a gradient of \textlessspan class="inline-formula"\textgreater4.20±0.8\textless/span\textgreater. This relationship has potential for using ground-based ionospheric measurements to infer quantitative variations in the composition of the neutral thermosphere via a relatively simple model. This has applications in understanding long-term change and the efficacy of the upper atmosphere on satellite drag.\textless/p\textgreater

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

Published by: Annales Geophysicae      Published on: mar

YEAR: 2021     DOI: 10.5194/angeo-39-309-2021

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 providing important constraints on models seeking to explain these features. We performed a seasonal and interannual analysis of GUVI limb O, O₂, and N₂ densities and volume number density ratio O/N₂ at constant pressure levels. These daytime observations of O and O/N₂ in the lower thermosphere show a strong AO at midlatitudes and a clear SAO at lower latitudes. The global mean GUVI O/N₂ number density ratio shows the AO, with slightly larger values in January than in July and a SAO with O/N₂ greater during equinoxes than at the solstices. O and N₂ densities on fixed pressure levels in the upper thermosphere are anticorrelated with solar extreme ultraviolet flux. On the other hand, O/N₂ is smaller during solar minimum and larger during solar maximum. The thermospheric AO and SAO in composition have a constant phase with altitude throughout the thermosphere.

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

Published by: Journal of Geophysical Research: Space Physics      Published on: 04/2019

YEAR: 2019     DOI: 10.1029/2019JA026544

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 transition region between F1 and F2 peaks can be expressed bythe \textquoteleftG\textquoteright factor, a function of ion production rate and loss rates via ion-atom interchange reactionsand dissociative recombination of molecular ions. This in turn can be expressed as the square of the ratio of ions lost via these processes. We compare estimatesof the G factor obtained from ionograms recorded at Kwajalein (9oN, 167.2oE) for 25 times during which theTIMED spacecraftrecordedapproximately co-located measurements of the neutral thermosphere.We find alinear relationship between √G and the molecular: atomic composition ratio,with agradient of 2.23 \textpm0.17 and an offset of 1.66 \textpm 0.19. This relationship reveals the potential for using ground-based ionospheric measurements to infer quantitative variations in the composition of the neutral thermosphere. Such information can be used to investigate spatial and temporal variations in thermospheric compositionwhich in turn has applications such as understanding the response of thermospheric composition to climate change and the efficacy of the upper atmosphere on satellite drag.

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

Published by: Annales Geophysicae Discussions      Published on: 03/2019

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

Introduction to NASA Living With a Star Institute special section on low Earth orbit satellite drag: Science and operational impact

Zhang, Yongliang; Paxton, Larry; Jones, James;

Published by: Space Weather      Published on:

YEAR: 2018     DOI:

Disturbances in the Thermosphere and Ionosphere: Current Understanding and Operational Impacts II Posters

Zhang, Yongliang; Paxton, Larry; Fuller-Rowell, Timothy; Jones, James;

Published by:       Published on:

YEAR: 2016     DOI:

Extreme Ultraviolet Variability Experiment (EVE) on~the~Solar Dynamics Observatory (SDO): Overview~of~Science Objectives, Instrument Design, Data~Products, and Model Developments

The highly variable solar extreme ultraviolet (EUV) radiation is the major energy input to the Earth\textquoterights upper atmosphere, strongly impacting the geospace environment, affecting satellite operations, communications, and navigation. The Extreme ultraviolet Variability Experiment (EVE) onboard the NASA Solar Dynamics Observatory (SDO) will measure the solar EUV irradiance from 0.1 to 105\ nm with unprecedented spectral resolution (0.1\ nm), temporal cadence (ten seconds), and accuracy (20\%). EVE includes several irradiance instruments: The Multiple EUV Grating Spectrographs (MEGS)-A is a grazing-incidence spectrograph that measures the solar EUV irradiance in the 5 to 37\ nm range with 0.1-nm resolution, and the MEGS-B is a normal-incidence, dual-pass spectrograph that measures the solar EUV irradiance in the 35 to 105\ nm range with 0.1-nm resolution. To provide MEGS in-flight calibration, the EUV SpectroPhotometer (ESP) measures the solar EUV irradiance in broadbands between 0.1 and 39\ nm, and a MEGS-Photometer measures the Sun\textquoterights bright hydrogen emission at 121.6\ nm. The EVE data products include a near real-time space-weather product (Level\ 0C), which provides the solar EUV irradiance in specific bands and also spectra in 0.1-nm intervals with a cadence of one minute and with a time delay of less than 15\ minutes. The EVE higher-level products are Level\ 2 with the solar EUV irradiance at higher time cadence (0.25\ seconds for photometers and ten seconds for spectrographs) and Level\ 3 with averages of the solar irradiance over a day and over each one-hour period. The EVE team also plans to advance existing models of solar EUV irradiance and to operationally use the EVE measurements in models of Earth\textquoterights ionosphere and thermosphere. Improved understanding of the evolution of solar flares and extending the various models to incorporate solar flare events are high priorities for the EVE team.

Woods, T.; Eparvier, F.; Hock, R.; Jones, A.; Woodraska, D.; Judge, D.; Didkovsky, L.; Lean, J.; Mariska, J.; Warren, H.; McMullin, D.; Chamberlin, P.; Berthiaume, G.; Bailey, S.; Fuller-Rowell, T.; Sojka, J.; Tobiska, W.; Viereck, R.;

Published by: Solar Physics      Published on: 01/2012

YEAR: 2012     DOI: 10.1007/s11207-009-9487-6

EVE; SDO; Solar EUV irradiance; Space weather research

Science of opportunity: Heliophysics on the FASTSAT mission and STP-S26

The FASTSAT spacecraft, which was launched on November 19, 2010 on the DoD STP-S26 mission, carries three instruments developed in joint collaboration by NASA GSFC and the

Rowland, Douglas; Collier, Michael; Sigwarth, John; Jones, Sarah; Hill, Joanne; Benson, Robert; Choi, Michael; Chornay, Dennis; Cooper, John; Feng, Steven; , others;

Published by:       Published on:

YEAR: 2011     DOI: 10.1109/AERO.2011.5747235

Correction of SOHO CELIAS/SEM EUV measurements saturated by extreme solar flare events

Didkovsky, LV; Judge, DL; Jones, AR; Wieman, S; Tsurutani, BT; McMullin, D;

Published by: Astronomische Nachrichten: Astronomical Notes      Published on:

YEAR: 2007     DOI:

The October 28, 2003 extreme EUV solar flare and resultant extreme ionospheric effects: Comparison to other Halloween events and the Bastille Day event

Some of the most intense solar flares measured in 0.1 to 0.8 nm x-rays in recent history occurred near the end of 2003. The Nov 4 event is the largest in the NOAA records (X28) and the Oct 28 flare was the fourth most intense (X17). The Oct 29 flare was class X7. These flares are compared and contrasted to the July 14, 2000 Bastille Day (X10) event using the SOHO SEM 26.0 to 34.0 nm EUV and TIMED SEE 0.1\textendash194 nm data. High time resolution, \~30s ground-base GPS data and the GUVI FUV dayglow data are used to examine the flare-ionosphere relationship. In the 26.0 to 34.0 nm wavelength range, the Oct 28 flare is found to have a peak intensity greater than twice that of the Nov 4 flare, indicating strong spectral variability from flare-to-flare. Solar absorption of the EUV portion of the Nov 4 limb event is a possible cause. The dayside ionosphere responds dramatically (\~2.5 min 1/e rise time) to the x-ray and EUV input by an abrupt increase in total electron content (TEC). The Oct 28 TEC ionospheric peak enhancement at the subsolar point is \~25 TECU (25 \texttimes 10¹² electrons/cm²) or 30\% above background. In comparison, the Nov 4, Oct 29 and the Bastille Day events have \~5\textendash7 TECU peak enhancements above background. The Oct 28 TEC enhancement lasts \~3 hrs, far longer than the flare duration. This latter ionospheric feature is consistent with increased electron production in the middle altitude ionosphere, where recombination rates are low. It is the EUV portion of the flare spectrum that is responsible for photoionization of this region. Further modeling will be necessary to fully understand the detailed physics and chemistry of flare-ionosphere coupling.

Tsurutani, B.; Judge, D.; Guarnieri, F.; Gangopadhyay, P.; Jones, A.; Nuttall, J.; Zambon, G.A.; Didkovsky, L.; Mannucci, A.J.; Iijima, B.; Meier, R.; Immel, T.J.; Woods, T.; Prasad, S.; Floyd, L.; Huba, J.; Solomon, S.; Straus, P.; Viereck, R.;

Published by: Geophysical Research Letters      Published on: 02/2005

YEAR: 2005     DOI: 10.1029/2004GL021475

Comparing the Measured N2 Lyman-Birge-Hopfield (LBH) Band Brightness in the Dayglow With Model Calculations: Investigating the Importance of Cascading as a Source of Excitation.

Aksnes, A; Eastes, R; Budzien, S; Dymond, K; Bailey, S; Jones, A;

Published by:       Published on:

YEAR: 2005     DOI:

Lookup tables for transionospheric effects on signals

Strickland, DJ; Barnes, RP; Kochenash, AJ; Jones, WA; Reilly, MH; Daniell, RE;

Published by: Radio Science      Published on:

YEAR: 2004     DOI: