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

Inferring nighttime ionospheric parameters with the far ultraviolet imager onboard the ionospheric connection explorer

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:

YEAR: 2018     DOI:

Radiative transfer modeling of the OI 135.6~nm emission in the nighttime ionosphere

Remote sensing of the nighttime OI 135.6\ nm emissions has been a widely used method for measuring the\ F\ region ionospheric plasma densities. In this work, we first develop a comprehensive radiative transfer model from first principles to investigate the effects of different physical processes on the production and transport of the 135.6\ nm photons in the ionosphere and then propose a new approach for estimating electron densities from the nightglow. The forward modeling investigation indicates that under certain conditions mutual neutralization can contribute up to \~38\% of the total production of the nighttime 135.6\ nm emissions. Moreover, depending on the ionospheric conditions, resonant scattering by atomic oxygen and pure absorption by oxygen molecules can reduce the limb brightness observed by satellite-borne instruments by up to \~40\% while enhancing the brightness viewing in the nadir direction by typically \~25\%. Further analysis shows that without properly addressing these effects in the inversion process, the peak electron density in the\ F\ region (NmF2) obtained using limb observations can be overestimated by up to \~24\%. For accurate estimation of the ionospheric electron density, we develop a new type of inverse model that accounts for the effects of mutual neutralization, resonant scattering, and pure absorption. This inversion method requires the knowledge of O and O₂\ densities in order to solve the radiative transfer equations. Application of the inverse model to the nighttime ionosphere in the noiseless cases demonstrates that the electron density can be accurately quantified with only \~1\% error in NmF2 and hmF2.

Qin, Jianqi; Makela, Jonathan; Kamalabadi, Farzad; Meier, R.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 11/2015

YEAR: 2015     DOI: 10.1002/jgra.v120.1110.1002/2015JA021687

OI 135.6-nm Emission; onosphere; Radiative transfer; remote sensing

Radiative transfer modeling of the OI 135.6 nm emission in the nighttime ionosphere

Qin, Jianqi; Makela, Jonathan; Kamalabadi, Farzad; Meier, RR;

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

YEAR: 2015     DOI:

Estimation of electron densities in the lower thermosphere from GUVI 135.6 nm tomographic inversions in support of SpreadFEx

Kamalabadi, F.; Comberiate, J.; Taylor, M.; Pautet, P.-D.;

Published by: Annales Geophysicae      Published on: Jan-01-2009

YEAR: 2009     DOI: 10.5194/angeo-27-2439-2009

Overview and summary of the Spread F Experiment (SpreadFEx)

We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx) performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI) and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian sector and included ground-based optical, radar, digisonde, and GPS measurements at a number of fixed and temporary sites. Related data on convection and plasma bubble structures were also collected by GOES 12, and the GUVI instrument aboard the TIMED satellite.\ 

Initial results of our SpreadFEx analyses are described separately by Fritts et al. (2009). Further analyses of these data provide additional evidence of 1) gravity wave (GW) activity near the mesopause apparently linked to deep convection predominantly to the west of our measurement sites, 2) small-scale GWs largely confined to lower altitudes, 3) larger-scale GWs apparently penetrating to much higher altitudes, 4) substantial GW amplitudes implied by digisonde electron densities, and 5) apparent influences of these perturbations in the lower F-region on the formation of equatorial spread F, RTI, and plasma bubbles extending to much higher altitudes. Other efforts with SpreadFEx data have also yielded 6) the occurrence, locations, and scales of deep convection, 7) the spatial and temporal evolutions of plasma bubbles, 8) 2-D (height-resolved) structures in electron density fluctuations and equatorial spread F at lower altitudes and plasma bubbles above, and 9) the occurrence of substantial tidal perturbations to the large-scale wind and temperature fields extending to bottomside F-layer and higher altitudes. Collectively, our various SpreadFEx analyses suggest direct links between deep tropical convection and large GW perturbations at large spatial scales at the bottomside F-layer and their likely contributions to the excitation of RTI and plasma bubbles extending to much higher altitudes.

Fritts, D.; Abdu, M.; Batista, B.; Batista, I.; Batista, P.; Buriti, R.; Clemesha, B.; Dautermann, T.; de Paula, E.; Fechine, B.; Fejer, B.; Gobbi, D.; Haase, J.; Kamalabadi, F.; Kherani, E.; Laughman, B.; Lima, P.; Liu, H.-L.; Medeiros, A.; Pautet, P.-D.; Riggin, D.; Rodrigues, F.; Sabbas, F.; Sobral, J.; Stamus, P.; Takahashi, H.; Taylor, M.; Vadas, S.; Vargas, F.; Wrasse, C.;

Published by: Annales Geophysicae      Published on: Jan-01-2009

YEAR: 2009     DOI: 10.5194/angeo-27-2141-2009

The Spread F Experiment (SpreadFEx): Program overview and first results

Fritts, D.; Abdu, M.; Batista, B.; Batista, I.; Batista, P.; Buriti, R.; Clemesha, B.; Dautermann, T.; de Paula, E.; Fechine, B.; Fejer, B.; Gobbi, D.; Haase, J.; Kamalabadi, F.; Kherani, E.; Laughman, B.; Lima, J.; Liu, H.-L.; Medeiros, A.; Pautet, P.-D.; Riggin, D.; Rodrigues, F.; Sabbas, Sao; Sobral, J.; Stamus, P.; Takahasi, H.; Taylor, M.; Vadas, S.; Vargas, F.; Wrasse, C.;

Published by: Earth Planets Space      Published on:

YEAR: 2009     DOI:

Gravity wave and tidal influences on equatorial spread F based on observations during the Spread F Experiment (SpreadFEx)

The Spread F Experiment, or SpreadFEx, was performed from September to November 2005 to define the potential role of neutral atmosphere dynamics, primarily gravity waves propagating upward from the lower atmosphere, in seeding equatorial spread F (ESF) and plasma bubbles extending to higher altitudes. A description of the SpreadFEx campaign motivations, goals, instrumentation, and structure, and an overview of the results presented in this special issue, are provided by Fritts et al. (2008a). The various analyses of neutral atmosphere and ionosphere dynamics and structure described in this special issue provide enticing evidence of gravity waves arising from deep convection in plasma bubble seeding at the bottomside F layer. Our purpose here is to employ these results to estimate gravity wave characteristics at the bottomside F layer, and to assess their possible contributions to optimal seeding conditions for ESF and plasma instability growth rates. We also assess expected tidal influences on the environment in which plasma bubble seeding occurs, given their apparent large wind and temperature amplitudes at these altitudes. We conclude 1) that gravity waves can achieve large amplitudes at the bottomside F layer, 2) that tidal winds likely control the orientations of the gravity waves that attain the highest altitudes and have the greatest effects, 3) that the favored gravity wave orientations enhance most or all of the parameters influencing plasma instability growth rates, and 4) that gravity wave and tidal structures acting together have an even greater potential impact on plasma instability growth rates and plasma bubble seeding.

Fritts, D.; Vadas, S.; Riggin, D.; Abdu, M.; Batista, I.; Takahashi, H.; Medeiros, A.; Kamalabadi, F.; Liu, H.-L.; Fejer, B.; Taylor, M.;

Published by: Annales Geophysicae      Published on: 10/2008

YEAR: 2008     DOI: 10.5194/angeo-26-3235-2008

A tomographic model for ionospheric imaging with the Global Ultraviolet Imager

Comberiate, J.; Kamalabadi, F.; Paxton, L.;

Published by: Radio Science      Published on: Jan-04-2007

YEAR: 2007     DOI: 10.1029/2005RS003348

Tomographic imaging of equatorial plasma bubbles

Comberiate, J.; Kamalabadi, F.; Paxton, L.;

Published by: Geophysical Research Letters      Published on: Jan-01-2006

YEAR: 2006     DOI: 10.1029/2006GL025820

Validation and Long-Term Studies of Equatorial Plasma Bubble Reconstructions With GUVI

Comberiate, J; Paxton, LJ; Kamalabadi, F;

Published by:       Published on:

YEAR: 2006     DOI:

Coordinated Observations of Equatorial Plasma Bubbles Using TIMED/GUVI and Ground-Based Instruments

Comberiate, J; Kamalabadi, F; Paxton, L;

Published by:       Published on:

YEAR: 2005     DOI:

Statistical Analysis of Equatorial Spread F Activity Seen From TIMED/GUVI

Comberiate, JM; Krekeler, JM; Kamalabadi, F; Paxton, LJ; Kil, H;

Published by:       Published on:

YEAR: 2004     DOI:

Characterization of Ionospheric Plasma Bubbles With the Global Ultraviolet Imager

Kamalabadi, F; Comberiate, J; Krekeler, J; Paxton, L;

Published by:       Published on:

YEAR: 2004     DOI:

The first coordinated ground- and space-based optical observations of equatorial plasma bubbles

We report on ionospheric optical emissions detected by the GUVI instrument on the TIMED satellite. As the satellite crosses the equatorial zone the bright Appleton Anomaly region is imaged. Often these bright zones are interrupted by regions slanted from west to east as the equator is approached forming a backwards \textquoteleftC\textquoteright-shape in the image. To explain this feature we use simultaneous ground-based observations looking equatorward from Hawaii using the 777.4-nm emission. We also compare these optical observations to inverted electron density maps, as well as to those made by radar and to numerical simulations of the Rayleigh-Taylor instability. The characteristic shape is a result of a shear in the eastward plasma flow velocity, which peaks near the F peak at the equator and decreases both above and below that height. The ability to detect these unstable and usually turbulent ionospheric regions from orbit provides a powerful global remote sensing capability for an important space weather process.

Kelley, Michael; Makela, J.; Paxton, L.; Kamalabadi, F.; Comberiate, J.; Kil, H.;

Published by: Geophysical Research Letters      Published on: 07/2003

YEAR: 2003     DOI: 10.1029/2003GL017301

Assimilation of Space-Based Ultraviolet Data Into a Recursive Global Ionospheric Model

Kamalabadi, F; Hajj, G; Pi, X; Wang, C; Wilson, B;

Published by:       Published on:

YEAR: 2003     DOI:

Low-Latitude Ionospheric Plasma Depletions: Imaging, Modeling, and Interpretation Using Space-Based Ultraviolet Measurements

Comberiate, JM; Kamalabadi, F; Paxton, L; Kil, H;

Published by:       Published on:

YEAR: 2003     DOI:

Detection and Mapping of Plasma Bubbles With the Global Ultraviolet Imager

Kamalabadi, F; Comberiate, J; Paxton, L; Kil, H;

Published by:       Published on:

YEAR: 2003     DOI:

The first coordinated ground-and space-based optical observations of equatorial plasma bubbles

Kelley, Michael; Makela, Jonathan; Paxton, Larry; Kamalabadi, Farzad; Comberiate, Joseph; Kil, Hyosub;

Published by: Geophysical Research Letters      Published on:

YEAR: 2003     DOI:

Characterization of Low Latitude Ionospheric Plasma Depletions Using Space-Based Ultraviolet Imaging

Comberiate, JM; Kamalabadi, F; Paxton, LJ; Kil, H;

Published by:       Published on:

YEAR: 2002     DOI: