Bibliography

Global observations of E region plasma density morphology and variability

Nicolls, Michael; Rodrigues, Fabiano; Bust, Gary;

Published by: Journal of Geophysical Research      Published on: Jan-01-2012

YEAR: 2012     DOI: 10.1029/2011JA017069

Global observations of E region plasma density morphology and variability

The global morphology and variability of the ionospheric E region plasma density are estimated from satellite-based radio occultation total electron content (ROTEC) measurements. Vertical profiles of E region electron density are estimated using the inversion technique recently proposed by Nicolls et al. (2009). In this technique, the F-region contribution to each ROTEC measurement is removed using an assimilative model of the ionosphere in order to mitigate the effects of F-region gradients in the estimation of E region profiles. The technique is applied to occultation observations made by GPS receivers onboard COSMIC satellites aided by F-region electron density specification provided by the Ionospheric Data Assimilation Four-Dimensional (IDA4D) algorithm. Global estimates of hmE, NmE, and E region total electron content (TEC) are presented for two different months: April 2007 and January 2008. Results of our analysis show that ROTEC measurements such as those provided by the COSMIC constellation can produce reasonable and valuable estimates of E region parameters on a global scale when properly treated for the effect of F-region density gradients. The agreement between the α-Chapman theory of ionization and recombination and estimated profiles is demonstrated. Reasonable estimates of E region variability can also be specified by the global measurements. The dependence of the E region variability on latitude is quantified and presented.

Nicolls, Michael; Rodrigues, Fabiano; Bust, Gary;

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

YEAR: 2012     DOI: https://doi.org/10.1029/2011JA017069

E region electron density; E region morphology; E region variability; radio occultation

Characteristics of traveling ionospheric disturbances observed by the TIDDBIT sounder

Crowley, Geoff; Rodrigues, FS;

Published by: Radio Science      Published on:

YEAR: 2012     DOI:

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

Estimating E region density profiles from radio occultation measurements assisted by IDA4D

Nicolls, MJ; Rodrigues, FS; Bust, GS; Chau, JL;

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

YEAR: 2009     DOI:

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:

Incoherent and coherent scatter radar studies of the equatorial F region

Radio waves are weakly scattered by thermal fluctuations in the quasiequilibrium ionospheric plasma. Coherent scatter echoes, meanwhile, are caused by non-thermal electron density fluctuations generated by plasma instabilities and are much stronger than incoherent scatter (IS) echoes. The spectra of IS echoes provide information about parameters of the background plasma such as electron density, temperatures, and ion composition. On the other hand, coherent scatter echoes provide an indication of the turbulent state of the ionospheric plasma. This dissertation describes coherent and incoherent backscatter radar observations of the F region ionosphere in the magnetic equatorial region using the Jicamarca IS radar in Peru and the Sao Lu ˜ ´ıs coherent backscatter radar in Brazil.

Rodrigues, Fabiano;

Published by:       Published on:

YEAR: 2008     DOI:

Coherent backscatter radar imaging in Brazil: large-scale waves in the bottomside F-region at the onset of equatorial spread F

Rodrigues, FS; Hysell, DL; de Paula, ER;

Published by:       Published on:

YEAR: 2008     DOI: