Seeding equatorial spread<i>F</i>with turbulent gravity waves: Phasing effects

Wu, Tangting; Huba, J. D.; Krall, J.; Fritts, David C.; Laughman, B.

doi:10.1002/2014gl062348

Cited by 17 publications

(17 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A mesoscale‐resolving whole atmosphere model with self‐consistent ionospheric electrodynamics is not yet available and will require significant computing resources. Idealized GWs and GWs from regional high‐resolution models have been used to drive ionosphere and plasmasphere models [ Krall et al , , , Hysell et al , ; Wu et al , ], and it is found that GW wavelength and geometry, propagation direction with respect to the Earth magnetic field lines, spatial distribution, and their phase structure can affect the initiation of ESF. These findings suggest that the predictability of the GWs in the upper atmosphere have important implications for the predictability of ESF, and it will be important to explore what the effects are of a complex global wave system on the ionosphere and thermosphere system and how sensitive they are to different wave spectra.…”

Section: Importance Of Mesoscale Processes For the Upper Atmosphere Vmentioning

confidence: 99%

Variability and predictability of the space environment as related to lower atmosphere forcing

2016

View full text Add to dashboard Cite

The Earth's thermosphere and ionosphere (TI) are characterized by perpetual variability as integral parts of the atmosphere system, with intermittent disturbances from solar and geomagnetic forcing. This review examines how the TI variability is affected by processes originating from the lower atmosphere and implications for quantifying and forecasting the TI. This aspect of the TI variability has been increasingly appreciated in recent years from both observational and numerical studies, especially during the last extended solar minimum. This review focuses on the role of atmospheric waves, including tides, planetary waves, gravity waves, and acoustic waves, which become increasingly significant as they propagate from their source region to the upper atmosphere. Recent studies have led to better understanding of how these waves directly or indirectly affect TI wind, temperature, and compositional structures; the circulation pattern; neutral and ion species transport; and ionospheric wind dynamo. The variability of these waves on daily to interannual scales has been found to significantly impact the TI variability. Several outstanding questions and challenges have been highlighted: (i) large, seemingly stochastic, day‐to‐day variability of tides in the TI; (ii) control of model error in the TI region by the lower atmosphere; and (iii) the increasing importance of processes with shorter spatial and temporal scales at higher altitudes. Addressing these challenges requires model capabilities to assimilate observations of both lower and upper atmosphere and higher model resolution to capture complex interactions among processes over a broad range of scales and extended altitudes.

show abstract

Section: Importance Of Mesoscale Processes For the Upper Atmosphere Vmentioning

confidence: 99%

Variability and predictability of the space environment as related to lower atmosphere forcing

2016

View full text Add to dashboard Cite

show abstract

“…The observation of wavelike structure at the bottomside of the F region and their effects on ESF were established by Patra et al []. Wu et al [] reported the role of turbulent gravity waves on ESF seeding. Manju et al [] quantified the strength of such perturbations required and showed that the amplitude of the gravity wave is a crucial parameter which determines the occurrence of ESF.…”

Section: Introductionmentioning

confidence: 95%

Gravity wave control on ESF day‐to‐day variability: An empirical approach

Aswathy

Manju

2017

JGR Space Physics

View full text Add to dashboard Cite

The gravity wave control on the daily variation in nighttime ionization irregularity occurrence is studied using ionosonde data for the period 2002–2007 at magnetic equatorial location Trivandrum. Recent studies during low solar activity period have revealed that the seed perturbations should have the threshold amplitude required to trigger equatorial spread F (ESF), at a particular altitude and that this threshold amplitude undergoes seasonal and solar cycle changes. In the present study, the altitude variation of the threshold seed perturbations is examined for autumnal equinox of different years. Thereafter, a unique empirical model, incorporating the electrodynamical effects and the gravity wave modulation, is developed. Using the model the threshold curve for autumnal equinox season of any year may be delineated if the solar flux index (F10.7) is known. The empirical model is validated using the data for high, moderate, and low solar epochs in 2001, 2004, and 1995, respectively. This model has the potential to be developed further, to forecast ESF incidence, if the base height of ionosphere is in the altitude region where electrodynamics controls the occurrence of ESF. ESF irregularities are harmful for communication and navigation systems, and therefore, research is ongoing globally to predict them. In this context, this study is crucial for evolving a methodology to predict communication as well as navigation outages.

show abstract

“…Wu et al, 2015). This implies that the coupling between the Perkins instability and CGWs can benefit the growth of MSTIDs.…”

Section: The Cgw Effects In the Ionosphere (Cases 2 And 3)mentioning

confidence: 96%

“…The NRL self-consistent SAMI3/ESF model is based on the NRL two-dimensional SAMI2 (Sami2 is Another Model of the Ionosphere) and three-dimensional SAMI3 model (Huba & Joyce, 2010;Huba et al, 2000). The SAMI3/ESF model includes an electric potential equation based on current conservation (∇ · J = 0), which has been applied to studies of ESF (Huba et al, 2009;Krall, Huba, Fritts, 2013;Krall, Huba, Joyce, & Hei, 2013;Wu et al, 2015) and nighttime MSTIDs (Duly et al, 2014). In this study, the SAMI2 is run for 43 hr to compute the simulated background ionosphere for initializing the SAMI3/ESF at each longitudinal plane.…”

Section: The Sami3/esf Modelmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Modeling of the Concentric Gravity Wave Seeding of Low‐Latitude Nighttime Medium‐Scale Traveling Ionospheric Disturbances

Chou

Lin

Huba

et al. 2018

Geophysical Research Letters

View full text Add to dashboard Cite

The first‐principles three‐dimensional ionosphere model Naval Research Laboratory SAMI3/ESF is used to study the low‐latitude nighttime medium‐scale traveling ionospheric disturbances (MSTIDs) triggered by the typhoon‐induced concentric gravity waves (CGWs) for the first time. Simulation results demonstrate that the electrodynamic coupling between CGWs and Perkins instability can initiate the rarely observed low‐latitude nighttime MSTIDs by accelerating their growth rates. Both the simulations and observations show that the westward and westward/equatorward propagating CGWs with similar wavefront alignments to the Perkins instability could enhance the generation of MSTIDs rather than the northward propagating CGWs. The CGWs penetrating to the ionospheric F layer without severe dissipation can induce greater polarization electric fields to accelerate the Perkins instability via E × B drifts.

show abstract

Seeding equatorial spreadFwith turbulent gravity waves: Phasing effects

Cited by 17 publications

References 20 publications

Variability and predictability of the space environment as related to lower atmosphere forcing

Variability and predictability of the space environment as related to lower atmosphere forcing

Gravity wave control on ESF day‐to‐day variability: An empirical approach

Numerical Modeling of the Concentric Gravity Wave Seeding of Low‐Latitude Nighttime Medium‐Scale Traveling Ionospheric Disturbances

Contact Info

Product

Resources

About