J. H. Sastri

TL;DR: In this article, a case study of the ionospheric, thermospheric, and geomagnetic conditions associated with the occasional onset of range spread F at Fortaleza (4°S, 38°W, dip latitude −1.8°, and magnetic declination 21°W), Brazil, in the June solstice, a season in which frequency spread F is typically seen in the postsunset hours (after 2000 LT).

TL;DR: In this article, the characteristics of the response of equatorial ionospheric zonal electric field and F-region plasma density to the asymmetric ring current intensifications that occurred in succession on 16 December 1991, corresponding to the STEP/EITS-2 campaign period are presented.

TL;DR: In this article, the geomagnetic and ionospheric manifestations of the DP 2 activity that occurred on April 7, 1995 using high-time resolution magnetometer data of IMAGE network in Scandinavia and of Alcantara (dip 1.2° N), Brazil, and F layer vertical plasma drift, V z. measured by an HF Doppler radar at Kodaikanal, India.

TL;DR: In this article, 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 descended thereafter.

TL;DR: In this article, the authors measured 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 February 1993 to determine the variation of the equatorial evening vertical drifts (V z ) with season, solar and magnetic activity.