Bibliography

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

Signatures of conjugate photoelectrons in the ionosphere and thermosphere

Kil, Hyosub; Paxton, Larry; Schaefer, Robert; Huba, Joseph;

Published by:       Published on:

YEAR: 2021     DOI:

Plasma depletions lasting into daytime during the recovery phase of a geomagnetic storm in May 2017: Analysis and simulation of GPS total electron content observations

This paper reports that plasma density depletions appearing at middle latitudes near sunrise survived until afternoon on 29 May 2017 during the recovery phase of a geomagnetic storm. By analyzing GPS data collected in Japan, we investigate temporal variations in the horizontal two-dimensional distribution of total electron content (TEC) during the geomagnetic storm. The SYM-H index reached −142 nT around 08 UT on 28 May 2017. TEC depletions extending up to approximately 38°N along the meridional direction appeared over Japan around 05 LT (LT = UT + 9 hours) on 29 May 2017, when TEC rapidly increased at sunrise due to the solar extreme ultraviolet (EUV) radiation. The TEC depletions appeared sequentially over Japan for approximately 8 hours in sunlit conditions. At 06 LT on 29 May, when the plasma depletions first appeared over Japan, the background TEC was enhanced to approximately 17 TECU, and then decreased to approximately 80\% of the TEC typical of magnetically quiet conditions. We conclude that this temporal variation of background plasma density in the ionosphere was responsible for the persistence of these plasma depletions for so long in daytime. By using the Naval Research Laboratory: Sami2 is Another Model of the Ionosphere (SAMI2), we have evaluated how plasma production and ambipolar diffusion along the magnetic field may affect the rate of plasma depletion disappearance. Simulation shows that the plasma density increases at the time of plasma depletion appearance; subsequent decreases in the plasma density appear to be responsible for the long-lasting persistence of plasma depletions during daytime. The plasma density depletion in the top side ionosphere is not filled by the plasma generated by the solar EUV productions because plasma production occurs mainly at the bottom side of the ionosphere.

Otsuka, Yuichi; Shinbori, Atsuki; Sori, Takuya; Tsugawa, Takuya; Nishioka, Michi; Huba, Joseph;

Published by: Earth and Planetary Physics      Published on:

YEAR: 2021     DOI: 10.26464/epp2021046

Ionosphere; GPS; ionospheric irregularity; plasma bubble; SAMI2

Modeling the Impact of Metallic Ion Layers on Equatorial Spread With SAMI3/ESF

The impact of region metal ion layers on the development of equatorial plasma bubbles is investigated using the SAMI3/ESF model. We find that metal ion layers reduce the growth rate of the generalized Rayleigh-Taylor instability (GRTI) and act to suppress the development of equatorial plasma bubbles. This is consistent with theoretical expectations and observations and is attributed to the increase in both the Pedersen and Hall conductances. Additionally, inhomogeneities in the region metal ion layer can map into the layer and alter the morphology of equatorial spread (ESF) bubble evolution. Lastly, we find that if EFS bubbles develop in the presence of a metal ion layer, then the electric fields generated by the instability can lift the metal ions into the region. This is consistent with observations of Fe in the region during equatorial spread .

Huba, J.; Krall, J.; Drob, D.;

Published by: Geophysical Research Letters      Published on: 02/2020

YEAR: 2020     DOI: 10.1029/2020GL087224

Equatorial ionosphere; Equatorial Spread F; metal ions; sporadic E

Thermospheric tidal effects on the ionospheric midlatitude summer nighttime anomaly using SAMI3 and TIEGCM

This paper is the first study to employ a three-dimensional physics-based ionosphere model, SAMI3, coupled with the National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) and Global Scale Wave Model to simulate the mesospheric and lower thermospheric tidal effects on the development of midlatitude summer nighttime anomaly (MSNA). Using this coupled model, the diurnal variation of MSNA electron densities at 300 km altitude is simulated on both June solstice (day of year (DOY) 167) and December solstice (DOY 350) in 2007. Results show successful reproduction of the southern hemisphere MSNA structure including the eastward drift feature of the southern MSNA, which is not reproduced by the default SAMI3 runs using the neutral winds provided by the empirical Horizontal Wind Model 93 neutral wind model. A linear least squares algorithm for extracting tidal components is utilized to examine the major tidal component affecting the variation of southern MSNA. Results show that the standing diurnal oscillation component dominates the vertical neutral wind manifesting as a diurnal eastward wave-1 drift of the southern MSNA in the local time frame. We also find that the stationary planetary wave-1 component of vertical neutral wind can cause diurnal variation of the summer nighttime electron density enhancement around the midlatitude ionosphere.

Chen, C.; Lin, C.; Chang, L.; Huba, J.; Lin, J.; Saito, A.; Liu, J;

Published by: Journal of Geophysical Research: Space Physics      Published on: 06/2013

YEAR: 2013     DOI: 10.1002/jgra.50340

MSNA; SAMI3; tidal effect; TIEGCM

SAMI3 Simulations of Ionospheric Variability from 1996 to 2011

McDonald, SE; Lean, J; Huba, JD; Emmert, JT; Drob, DP; Siefring, CL; Meier, RR; Picone, J;

Published by:       Published on:

YEAR: 2012     DOI:

Simulating Ionospheric Variability in the Descending Phase of Solar Cycle-23 using SAMI3

McDonald, SE; Lean, J; Huba, JD; Joyce, GR; Emmert, JT; Drob, DP; Stephan, AW; Siefring, CL; Meier, RR; Picone, J;

Published by:       Published on:

YEAR: 2011     DOI:

Modeling of multiple effects of atmospheric tides on the ionosphere: An examination of possible coupling mechanisms responsible for the longitudinal structure of the equatorial ionosphere

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

Integrating the Sun-Earth System for the Operational Environment (ISES-OE)

Lean, J.; Huba, J.; McDonald, S.; Slinker, S.; Drob, D.; Emmert, J.; Meier, R.; Picone, J.; Joyce, G.; Krall, J.; Stephan, A.; Roach, K.; Knight, H.; Plunkett, S.; Wu, C.-C.; Wood, B.; Wang, Y.-M.; Howard, R.; Chen, J.; Bernhardt, P.; Fedder, J.;

Published by:       Published on:

YEAR: 2010     DOI:

Day-to-day variability of the equatorial ionization anomaly and scintillations at dusk observed by GUVI and modeling by SAMI3

Basu, Su.; Basu, S.; Huba, J.; Krall, J.; McDonald, S.; Makela, J.; Miller, E.; Ray, S.; Groves, K.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2009

YEAR: 2009     DOI: 10.1029/2008JA013899

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

Sun-to-Earth Imaging for Operational Space Weather Monitoring

Chua, DH; Wood, BE; Slinker, SP; Meier, RR; Englert, CR; Socker, DG; Huba, J; Krall, J;

Published by:       Published on:

YEAR: 2009     DOI:

Three-dimensional equatorial spread F modeling: Zonal neutral wind effect

Joyce, GR; Huba, J; Ossakow, SL; Krall, J; England, S;

Published by:       Published on:

YEAR: 2009     DOI:

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:

YEAR: 2009     DOI:

Equatorial anomaly development and collapse at dusk observed by TIMED/GUVI and modeled by SAMI3

Basu, Sunanda; Basu, Sunanda; Huba, J; Krall, J; Basu, Santimay; Makela, Jonathan;

Published by: 37th COSPAR Scientific Assembly      Published on:

YEAR: 2008     DOI:

Modeling the longitudinal variation in the post-sunset far-ultraviolet OI airglow using the SAMI2 model

England, SL; Immel, TJ; Huba, JD;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2008     DOI:

Modeling of Equatorial Anomaly Development and Collapse at Dusk Observed by TIMED/GUVI Over Indian Longitudes

Basu, S; Huba, J; Makela, J; Ray, S; Groves, K;

Published by:       Published on:

YEAR: 2007     DOI:

Equatorial anomaly development mapped by TIMED/GUVI: Occurrence/suppression of scintillations at low latitudes and their modeling

Basu, S; Basu, S; Makela, J; Miller, E; Dasgupta, A; Roy, S; Huba, J; Groves, K; Rich, F;

Published by: Eos Trans. AGU      Published on:

YEAR: 2006     DOI:

Modeling of Equatorial Anomaly Development and Collapse at Dusk Observed by TIMED/GUVI

Basu, S; Huba, J; Makela, J; Miller, E; Groves, K;

Published by:       Published on:

YEAR: 2006     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

Ionospheric and dayglow responses to the radiative phase of the Bastille Day flare

Meier, RR; Warren, HP; Nicholas, AC; Bishop, J; Huba, JD; Drob, DP; Lean, JL; Picone, JM; Mariska, JT; Joyce, G; , others;

Published by: Geophysical research letters      Published on:

YEAR: 2002     DOI: