The determination of whistler nose-frequency and minimum group delay and its implication for the measurement of the east-west electric field and tube content in the magnetosphere

1996

J. geomagn. geoelec

Particular emphasis is laid on the application of whistlers recorded at low latitude ground station, Nainital during magnetically quiet times to estimate the eastward/westward electric field in the plasmasphere. The east-west components of electric field during quiet magnetic (average Kp = 1) are obtained for the first time from low latitude station on the basis of the available whistler data on Tarcsai (1975). Our measurements demonstrate an average estimated electric field of-0.06 mVm 1 in the premidnight local time sector and an average westward electric field of -0.05 mVm I in the post-midnight local time sector. These values are in good agreement with similar results reported by earlier workers. Near midnight there is a sharp transition from eastward field to westward electric field. The electric fields during quiet days at low latitudes are thought to be generated by the dynamo mechanism.

Section: Methods Of Analysismentioning

confidence: 99%

An Estimate of Quiet Time Plasmaspheric Electric Fields from Whistler Observations at Low Latitude.

Lalmani¹,

Ahmad²,

1996

J. geomagn. geoelec

“…The present estimation of f n has an error of about 10%. For diffusive equilibrium f n = 0.38f H e (Sagredo et al 1973). Sazhin et al (1990) estimated this multiplying parameter to vary between 0.38 and 0.40.…”

Section: Propagation Path Of Whistlersmentioning

confidence: 99%

Simultaneous observation of whistlers and emissions during a geomagnetically quiet period at low latitude

Lalmani

2010

Astrophys Space Sci

A unique night-time natural electromagnetic disturbances in the VLF/ELF range received during a magnetically quite period at a low latitude Indian ground station, Jammu (geomag. lat. 19°26 N, L = 1.17) has been reported. During the routine observation of VLF waves at Jammu, whistlers and different types of VLF/ELF emissions such as whistlers of varying dispersion confined to a small band limited frequency range, hisslers, pulsing hiss, discrete chorus emissions of rising and falling tones with multiple bands, oscillating tone discrete emission, whistler-triggered hook and discrete chorus risers emissions, etc. have been observed simultaneously during the quiet period on a single night. Such type of unique simultaneous observations has never been reported from any of the low latitude ground stations and this is the first observation of its kind. The results are discussed in the light of recorded features of whistlers and emissions. Generation and propagation mechanism are discussed briefly. Plasma parameters are further derived from the dispersion analysis of nighttime whistlers and emissions recorded simultaneously during magnetically quiet periods.

“…Total electron contents in a magnetic flux tube of unit cross sectional area at the reference height is estimated by evaluating the integral (Park, 1972;Sagredo et al, 1973;Singh et al, 1993)…”

Section: Observations and Analysismentioning

confidence: 99%

“…Carpenter et al (1972) and Sagredo et al (1973) have shown that in an active period, if a large number of whistlers are analysed, the electric field can be estimated with a precision of 0.1 mV/m.…”

Section: Introductionmentioning

confidence: 99%

A case study of whistlers recorded at Varanasi (L = 1.07)

et al. 2014

Earth Planet Sp

Large number of high dispersion whistlers recorded at low latitude station Varanasi (L = 1.07) are analysed and it is find out that they have propagated along L 2.12-2.76. This is explained by considering the propagation of whistlers through the earth-ionosphere wave guide after exiting from the duct towards the equator. Using diffusive equilibrium model (DE-1), we have estimated equatorial electron density, total electron content in a flux tube and large scale convective electric fields which are in good agreement with the results reported by other workers from the analysis of mid latitude whistlers. The significance of this paper is to probe mid latitude plasmasphere using whistlers recorded at low latitudes. Further, an attempt has been made to study the propagation mechanism of low latitude whistlers.