Tomographic studies of aeronomic phenomena using radio and UV techniques

Kamalabadi, F.; Bust, G. S.; Dymond, K. F.; González, S. A.; Bernhardt, P. A.; Chakrabarti, Supriya; Cotton, Daniel M.; Stephan, A. W.; McCoy, R. P.; Budzien, S. A.; Thonnard, S. E.

doi:10.1016/s1364-6826(02)00096-2

Cited by 29 publications

(26 citation statements)

References 19 publications

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“…The descending node of each TIMED orbit provides two views of the plasma depletions having a component normal to the magnetic field from which tomographic retrievals of electron densities may be performed (Kamalabadi et al, 1999(Kamalabadi et al, , 2002Comberiate et al, 2007). The major assumption was that electron density fluctuations were approximately constant along magnetic field lines.…”

Section: Implications Of Plasma Measurements For Gw Parametersmentioning

confidence: 99%

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

et al. 2008

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Abstract. 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.

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Section: Implications Of Plasma Measurements For Gw Parametersmentioning

confidence: 99%

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

et al. 2008

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“…But, as the regularization approach tries to find a solution which is vertically as well as horizontally smooth, one has to choose an optimum regularization. In case of second order regularization, the large gradients are heavily penalized (Kamalabadi et al, 2002), thus tending to hide important aspects of the image of a highly disturbed ionosphere. A first order regularization should be a better option in such cases.…”

Section: The Algorithmmentioning

confidence: 99%

“…All the irregularities preserve their positions in latitude and altitude in the reconstructed image. It should be noted that the regularization approach introduces a smoothening effect in the gradients of electron density (Kamalabadi et al, 2002). It has been noticed during the simulation of different test cases that in case of a highly disturbed ionosphere, first order regularization is optimum.…”

Section: Reconstruction Of Complicated Irregularitiesmentioning

confidence: 99%

“…A number of theoretical as well as experimental CIT schemes have been reported so far in literature (Raymund et al, 1990;Fremouw et al, 1992;Na and Lee, 1990, 1994Afraimovitch et al, 1992;Andreeva et al, 1990Andreeva et al, , 1992Andreeva et al, , 2001Tereshchenko, 1991, 1992;Klobuchar et al, 1992;Pryse and Kersley, 1992;Kunitake et al, 1995;Kersley et al, 1997;Zhou et al, 1999;Tsai et al, 2002;Kamalabadi et al, 2002;Bhuyan et al, 2002). The Algebraic Reconstruction Technique, ART (Austen et al, 1988), the Multiplicative Algebraic Reconstruction Technique, MART (Raymund et al, 1990;Kersley et al, 1993) and Maximum Entropy Method, MEM (Fougere, 1995) are some of the widely used CIT algorithms.…”

Section: Introductionmentioning

confidence: 99%

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Application of generalized singular value decomposition to ionospheric tomography

2004

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Abstract. The electron density distribution of the low-and mid-latitude ionosphere has been investigated by the computerized tomography technique using a Generalized Singular Value Decomposition (GSVD) based algorithm. Model ionospheric total electron content (TEC) data obtained from the International Reference Ionosphere 2001 and slant relative TEC data measured at a chain of three stations receiving transit satellite transmissions in Alaska, USA are used in this analysis. The issue of optimum efficiency of the GSVD algorithm in the reconstruction of ionospheric structures is being addressed through simulation of the equatorial ionization anomaly (EIA), in addition to its application to investigate complicated ionospheric density irregularities. Results show that the Generalized Cross Validation approach to find the regularization parameter and the corresponding solution gives a very good reconstructed image of the low-latitude ionosphere and the EIA within it. Provided that some minimum norm is fulfilled, the GSVD solution is found to be least affected by considerations, such as pixel size and number of ray paths. The method has also been used to investigate the behaviour of the mid-latitude ionosphere under magnetically quiet and disturbed conditions.

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“…Examples of some common techniques and some experiments are given in Bernhardt et al (1998) and Kamalabadi et al (2002).…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2009

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Abstract. The SpreadFEx campaign was conducted with the goal of investigating potential neutral atmospheric dynamics influences in seeding plasma instabilities and bubbles extending to higher altitudes from September to November 2005, with primary measurements in Brazil. In this paper, we present the results of space-based UV and ground-based optical observations in support of this campaign. Specifically, we present multi-dimensional electron density images obtained tomographically from the 135.6 nm emissions measured by the GUVI instrument aboard the TIMED satellite that result from radiative recombination of O + and compare those with the corresponding 630.0 nm OI images recorded in the Brazilian sector. The GUVI results provide altitude vs. longitude information on depleted regions in the ionospheric plasma density that are complementary to the single-height latitude-longitude images obtained with the airglow imager.

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Tomographic studies of aeronomic phenomena using radio and UV techniques

Cited by 29 publications

References 19 publications

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

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

Application of generalized singular value decomposition to ionospheric tomography

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

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