The impact of gravity waves rising from convection in the lower atmosphere on the generation and nonlinear evolution of equatorial bubble
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In this article, a nonlinear evolution of equatorial F-region plasma bubbles under varying ambient ionospheric conditions and gravity wave seeding perturbations in the bottom-side F-layer is studied.Abstract:
. The nonlinear evolution of equatorial F-region plasma bubbles under varying ambient ionospheric conditions and gravity wave seeding perturbations in the bottomside F-layer is studied. To do so, the gravity wave propagation from the convective source region in the lower atmosphere to the thermosphere is simulated using a model of gravity wave propagation in a compressible atmosphere. The wind perturbation associated with this gravity wave is taken as a seeding perturbation in the bottomside F-region to excite collisional-interchange instability. A nonlinear model of collisional-interchange instability (CII) is implemented to study the influences of gravity wave seeding on plasma bubble formation and development. Based on observations during the SpreadFEx campaign, two events are selected for detailed studies. Results of these simulations suggest that gravity waves can play a key role in plasma bubble seeding, but that they are also neither necessary nor certain to do so. Large gravity wave perturbations can result in deep plasma bubbles when ionospheric conditions are not conducive by themselves; conversely weaker gravity wave perturbations can trigger significant bubble events when ionospheric conditions are more favorable. But weak gravity wave perturbations in less favorable environments cannot, by themselves, lead to strong plasma bubble responses.read more
Citations
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Gravity wave initiation of equatorial spread F/plasma bubble irregularities based on observational data from the SpreadFEx campaign
TL;DR: In this paper, the role of gravity waves in the instability initiation leading to equatorial spread F development was investigated using ground-based experiments conducted during the 2005 SpreadFEx campaign in Brazil.
Journal ArticleDOI
Simultaneous observation of ionospheric plasma bubbles and mesospheric gravity waves during the SpreadFEx Campaign
H. Takahashi,Michael J. Taylor,Pierre-Dominique Pautet,Amauri Fragoso de Medeiros,Delano Gobbi,Cristiano Max Wrasse,Joaquim Fechine,M. A. Abdu,Inez S. Batista,Eurico R. de Paula,J. H. A. Sobral,Daniela C. S. Arruda,Sharon L. Vadas,F. S. Sabbas,David C. Fritts +14 more
TL;DR: In this article, two airglow CCD imagers, located at Cariri (7.4° S, 36.5° W, geomag. 11° S) and near Brasilia (14.8°S, 47.6°W, geOMag. 10°S) were operated simultaneously and measured the equatorial ionospheric bubbles and their time evolution by monitoring the airglove OI 6300 intensity depletions.
Journal ArticleDOI
Equatorial spread F/plasma bubble irregularities under storm time disturbance electric fields
TL;DR: In this paper, a comprehensive analysis and discussion of the processes of ESF development, suppression or disruption under different phases of a storm activity sequence is presented, and the consequences for ESF occurrence from undershielding and over-shielding penetration electric fields as well as from the disturbance winds and wind dynamo electric field occurring in different local time sectors of the night, as also the irregularity dynamics and longitude extension.
Journal ArticleDOI
Convective ionospheric storms: a review
TL;DR: A major goal of the National Space Weather Program, and of C/NOFS, is predicting these storms, analogous to thunderstorms in the lower atmosphere due to their adverse effects on communication and navigation signals.
Journal ArticleDOI
On equatorial spread F: Establishing a seeding hypothesis
TL;DR: In this paper, a seeding hypothesis for the equatorial spread F (ESF) was proposed, based on the discovery that a direct link exists between regions of deep convective activity in the troposphere, where atmospheric gravity waves (GWs) are spawned, and the occurrence frequency of ESF during solstices.
References
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Journal ArticleDOI
Thermospheric responses to gravity waves arising from mesoscale convective complexes
Sharon L. Vadas,David C. Fritts +1 more
TL;DR: In this article, the authors employ a linear model of the responses to local body forces to estimate the spectra of gravity waves arising due to vertical motions within mesoscale convective complexes (MCCs) at equatorial latitudes.
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Gravity wave and tidal influences on equatorial spread F based on observations during the Spread F Experiment (SpreadFEx)
David C. Fritts,Sharon L. Vadas,Dennis M. Riggin,M. A. Abdu,Inez S. Batista,H. Takahashi,Amauri Fragoso de Medeiros,Farzad Kamalabadi,Hanli Liu,Bela G. Fejer,Michael J. Taylor +10 more
TL;DR: In this paper, the authors used the results of the SpreadFEx campaign to estimate gravity wave characteristics at the bottomside F layer, and to assess their possible con- tributions to optimal seeding conditions for equatorial spread F and plasma instability growth rates.
Journal ArticleDOI
The Condor Equatorial Spread F Campaign: Overview and results of the large‐scale measurements
Michael C. Kelley,James LaBelle,Erhan Kudeki,Bela G. Fejer,Sa. Basu,Su. Basu,K. D. Baker,Christian Hanuise,P. Argo,Ronald F. Woodman,Wesley E. Swartz,Donald T. Farley,John W. Meriwether +12 more
TL;DR: In this article, the authors report on the results of the experiments designed to study the equatorial F region and conclude that at least two factors other than the classical gravitational Rayleigh-Taylor plasma instability process must operate to yield the longest-scale horizontal organization of spread F structures.
Journal ArticleDOI
Nonlinear Rayleigh-Taylor instabilities, atmospheric gravity waves and equatorial spread F
TL;DR: In this article, it was shown that the Rayleigh-Taylor instability initiated by gravity waves can be saturated by nonlinear coupling of unstable modes to damped modes if the amplitude of the seed gravity wave is small and if the relative plasma density perturbations can reach 50% or more.
Journal ArticleDOI
Equatorial spread-F by electric fields and atmospheric gravity waves generated by thunderstorms
TL;DR: In this paper, a model based on the typical features of seasonal and geographical variation of tropical convection generating the traveling ionospheric disturbances (TIDs) is presented which can explain seasonal and geographic variations of premidnight equatorial spread-F occurrence.