lonization transport effects in the equatorial<i>F</i>region

Hanson, W. B.; Moffett, R. J.

doi:10.1029/jz071i023p05559

Cited by 484 publications

(314 citation statements)

References 29 publications

Supporting

Mentioning

307

Contrasting

Order By: Relevance

“…The existence of the equatorial anomaly is explained by an ionization transport mechanism commonly referred to as the equatorial fountain effect [Hanson and Moffett, 1966;Moffett, 1979], which lifts the equatorial plasma to a height of several hundreds to over one thousand kilometers. Recent computer simulations [Balan and Bailey, 1995] and experimental data [Vladimer et al, 1999] show that the fountain created by uplifting electrodynamic ExB drift at the geomagnetic equator must be supplemented by neutral wind effects.…”

Section: Discussionmentioning

confidence: 99%

Some features of the equatorial anomaly revealed by ionospheric tomography

Andreeva¹,

Franke²,

Yeh³

et al. 2000

Geophysical Research Letters

View full text Add to dashboard Cite

Abstract. The equatorial anomaly in ionization density has been imaged using the computerized ionospheric tomography technique applied to data from a low-latitude ionospheric tomography network. Examples of images representative of typical conditions during equinox and low solar flux are presented and shown to exhibit some characteristic features which have not been observed directly previously. The EA core, comprising the highest density region of the EA, is shown to exhibit a characteristic structure and asymmetry. These characteristics are quantified using measures of the ionospheric slab thickness and altitude, and they are discussed in light of the fountain mechanism which is responsible for formation of the EA.

show abstract

Section: Discussionmentioning

confidence: 99%

Some features of the equatorial anomaly revealed by ionospheric tomography

Andreeva¹,

Franke²,

Yeh³

et al. 2000

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…These have been called the Appleton (also named equatorial) ionization anomalies. They are the result of the upward motion of the plasma at the magnetic equator and its consequent diffusion obliquely along the magnetic field lines [Hanson and Moffett, 1966]. The total electron content (TEC) anomaly starts to develop as early as 1100 LT.…”

Section: Introductionmentioning

confidence: 99%

Measurement of the latitudinal distributions of total electron content during equatorial spread F events

Valladares¹,

Basu²,

Groves³

et al. 2001

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…The transport of ionization is mainly controlled by the equatorial fountain effect. The electrodynamic ExB drift at the magnetic equator and subsequent diffusion generates the plasma fountain and anomaly (Hanson and Moffett, 1966). The neutral wind makes the fountain and anomaly asymmetric (Balan and Bailey, 1995).…”

Section: Resultsmentioning

confidence: 99%

“…During daytime the ionization distribution in the ionosphere of the low-latitude region is modified by the fountain effect (Hanson and Moffett, 1966). The electrodynamic ExB drift produces a trough of ionization at the equator with two crests around 15 • -20 • geomagnetic latitudes -known as the equatorial ionization anomaly.…”

Section: Introductionmentioning

confidence: 99%

Solar control of ambient ionization of the ionosphere near the crest of the equatorial anomaly in the Indian zone

Chakraborty¹,

Hajra²

2008

Ann. Geophys.

View full text Add to dashboard Cite

Abstract. Long-term (1978Long-term ( -1990 total electron content (TEC) data have been analyzed to show the dependence of ambient ionization on EUV radiation from the Sun. TEC observations were made at Calcutta (22.58 • N, 88.38 • E geographic, dip: 32 • N), situated virtually below the northern crest of the equatorial ionization anomaly. Day-to-day changes in TEC at different local times do not show any significant correlation with F10.7 solar flux. A good correlation is, however, observed between the F10.7 solar flux and the monthly mean TEC when both are considered on a long-term basis, i.e. either in the ascending (1986)(1987)(1988)(1989)(1990) or in the descending (1979-1985) phase. In the early morning hours the correlation coefficient maximizes around the 08:00-10:00 h IST interval. The flux independent nature of diurnal TEC is evident around the noon time hours of only a few months in the descending phase for F10.7 values greater than 150 unit. Variation of TEC for the whole time period (1979)(1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989)(1990)) also exhibits a prominent hysteresis effect. The remarkable feature of the hysteresis effect is its local time dependence, leading to a temporal flip-over. Solar flux-normalized TEC values show a clear seasonal dependence with asymmetrical variations in the two equinoxes. The amplitudes of the equinoctial peaks reveal a prominent local time dependence. A further normalization leads to a typical local time variation of TEC. Based on solar flux, seasonal and local time dependent features of TEC, an empirical formula has been developed to represent the TEC variation in the early morning hours. It yields a quantitative estimate of the solar flux dependent nature of the TEC variation. The formula has been validated using the available TEC data and data from the neural network.

show abstract

lonization transport effects in the equatorialFregion

Cited by 484 publications

References 29 publications

Some features of the equatorial anomaly revealed by ionospheric tomography

Some features of the equatorial anomaly revealed by ionospheric tomography

Measurement of the latitudinal distributions of total electron content during equatorial spread F events

Solar control of ambient ionization of the ionosphere near the crest of the equatorial anomaly in the Indian zone

Contact Info

Product

Resources

About