Search Results - "Sastri, J. H."

Distinctive effects of interplanetary electric field and substorm on nighttime equatorial F layer: A case study by Chakrabarty, D., Sekar, R., Sastri, J. H., Ravindran, Sudha

“…A geomagnetic storm event is identified wherein the base of the equatorial F layer (h′F) over dip equator moved unusually upward till premidnight hours and…”
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Evidence for OI 630.0 nm dayglow variations over low latitudes during onset of a substorm by Chakrabarty, D., Sekar, R., Sastri, J. H., Pathan, B. M., Reeves, G. D., Yumoto, K., Kikuchi, T.

“…Observations of OI 630.0 nm dayglow intensity from Mt. Abu (magnetic latitude (MLAT): 16.2°N; magnetic longitude (MLONG): 148°E) at two different directions…”
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Summer-winter hemisphere asymmetry of the preliminary reverse impulse of geomagnetic storm sudden commencements at midlatitudes by Sastri, J. H., Yumoto, K., Rao, J. V. S. V., Ikeda, A.

“…We present event‐specific observational evidence for the prevalence of a summer‐winter hemisphere asymmetry of the preliminary reverse impulse (PRI) of…”
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Preliminary impulse of the geomagnetic storm sudden commencement of November 18, 1993 by Sastri, J. H., Takeuchi, T., Araki, T., Yumoto, K., Tsunomura, S., Tachihara, H., Luehr, H., Watermann, J.

“…The characteristics of the geomagnetic sudden commencement (SC) that occurred at 1211:30 UT on November 18, 1993, following an interval of prolonged…”
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DP 2 electric field fluctuations in the dusk-time dip equatorial ionosphere by Abdu, M. A., Sastri, J. H., Luhr, H., Tachihara, H., Kitamura, T., Trivedi, N. B., Sobral, J. H. A.

“…We have studied the geomagnetic and ionospheric manifestations of the DP 2 activity that occurred on April 7, 1995 using high time resolution magnetometer data…”
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Onset conditions of equatorial (range) spread F at Fortaleza, Brazil, during the June solstice by Sastri, J. H., Abdu, M. A., Batista, I. S., Sobral, J. H. A.

“…Case studies are made of the ionospheric, thermospheric, and geomagnetic conditions associated with the occasional onset of range spread F at Fortaleza (4°S,…”
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Response of equatorial ionosphere to episodes of asymmetric ring current activity by SASTRI, J. H, ABDU, M. A, SOBRAL, J. H. A

“…We present the characteristics of the response of equatorial ionospheric zonal electric field and F-region plasma density to the asymmetric ring current…”
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Global magnetospheric-ionospheric oscillations initiated by a solar wind pressure impulse by Huang, Chao-Song, Foster, J. C., Reeves, G. D., Watermann, J., Sastri, J. H., Yumoto, K., Song, P.

“…We present simultaneous observations of long‐period (∼1 hour) global magnetospheric‐ionospheric oscillations with multiple spacecraft and ground‐based…”
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Solar flare effects on the geomagnetic elements during normal and counter electrojet periods by RASTOGI, R. G, PATHAN, B. M, RAO, D. R. K, SASTRY, T. S, SASTRI, J. H

“…The paper describes the study of solar flare effects (sfe) on horizontal (H), eastward (Y) and vertical (Z) components of the geomagnetic field at the…”
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Letter to the Editor: Post-midnight onset of spread-F at Kodaikanal during the June solstice of solar minimum by Sastri, J. H.

“…At dip equatorial stations in the Indian zone, spread-F conditions are known to develop preferentially around midnight during the June solstice (northern…”
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Sporadic-E associated with the Leonid meteor shower event of November 1998 over low and equatorial latitudes by CHANDRA, H, SHARMA, S, DEVASIA, C. V, SUBBARAO, K. S. V, SRIDHARAN, R, SASTRI, J. H, RAO, J. V. S. V

“…Rapid radio soundings were made over Ahmedabad, a low latitude station during the period 16–20 November 1998 to study the sporadic-E layer associated with the…”
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Equatorial disturbance dynamo electric field longitudinal structure and spread F: a case study from GUARA/EITS campaigns by Abdu, MA, Sastri, J H, MacDougall, J, Batista, I S, Sobral, JHA

“…Digisondes/ionosondes, an HF Doppler radar and magnetometers were operated in Brazil and India during the September/October 1994 GUARA/EITS campaigns. Analysis…”
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Nighttime thermospheric meridional winds at Cachoeira Paulista (23°S, 45°W): Evidence for effects of the equatorial midnight pressure bulge by Batista, Inez S., Sastri, J. H., Medeiros, R. T., Abdu, M. A.

“…We have studied the local time and seasonal variations of thermospheric nighttime meridional winds at the low‐latitude station, Cachoeira Paulista, Brazil,…”
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On latitudinal profile of Storm Sudden Commencement in H, Y and Z at Indian geomagnetic observatory chain by RASTOGI, R. G, PATHAN, B. M, RAO, D. R. K, SASTRY, T. S, SASTRI, J. H

“…The unique network of geomagnetic observatories along 145°E geomagnetic longitude extending from the magnetic equator to the north pole has enabled to study…”
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Solar cycle and seasonal variations in F-region vertical drifts over Kodaikanal, India by K. B. Ramesh, J. H. Sastri

“…Measurements of the changes in phase path of F-region reflections at normal incidence at Kodaikanal (77° 28'E, 10° 14'N, dip 3°N) from February 1991 to…”
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Penetration electric fields at the nightside dip equator associated with the main impulse of the storm sudden commencement of 8 July 1991 by Sastri, J. Hanumath

“…The geomagnetic storm sudden commencement (ssc) of 8 July 1991 was reported [Wilson et al., 2001] to be characterized by a reduction (enhancement) of X…”
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Signatures for magnetospheric substorms in the geomagnetic field of dayside equatorial region: Origin of the ionospheric component by Sastri, J. Hanumath, Kamide, Y., Yumoto, K.

“…An event‐based study is made of the conditions that lead to the ionospheric current component in the geomagnetic field signature for magnetospheric substorms…”
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Coherent Radio Beacon Experiment (CRABEX) for tomographic imaging of the equatorial ionosphere in the Indian longitudes – Preliminary results by Thampi, Smitha V., Ravindran, Sudha, Devasia, C.V., Sreelatha, P., Pant, Tarun K., Sridharan, R., Ratnam, D. Venkata, Sarma, A.D., Reddi, C. Raghava, Jose, Jessy, Sastri, J.H.

“…To investigate the equatorial ionospheric processes like the equatorial ionization anomaly (EIA), equatorial spread F (ESF) and their inter relationships, a…”
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On the development of abnormally large postsunset upward drift of equatorial F region under quiet geomagnetic conditions by Sastri, J. Hanumath

“…The regular postsunset enhancement of upward drift of the equatorial F region is observed to be abnormally large on certain quiet days (Ap ≤ 5) as manifested…”
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Equatorial disturbance dynamo electric field longitudinal structure and spread F: A case study from GUAR/EITS Campaigns by Abdu, M. A., Sastri, J. H., MacDougall, J., Batista, I. S., Sobral, J. H. A.

“…Digisondes/ionosondes, an HF Doppler radar and magnetometers were operated in Brazil and India during the September/October 1994 GUARA/EITS campaigns. Analysis…”
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