Nighttime F-layer Vertical Movements over Indian Low & Midlatitude Stations

Abstract

Nighttime hourly rate of change of h' F is computed for Kodaikanal, Hyderabad and Ahmedabad representing, respectively, the equatorial, low and midlatitude stations in India. Data for several years are considered for examining the nature of nighttime F-layer vertical movements at the above latitudes. Vertical movements at Kodaikanal seem to be controlled by the electrodynamic (E x B) effects and those at Ahmedabad are influenced by meridional neutral wind effects. At an intermediate latitude (low midlatitude) station like Hyderabad, the dynamical behaviour of the F-layer could be due to the competing effects of neutral winds, electric fields and diffusion. The observed seasonal variations in nighttime vertical drifts also confirm the above conclusions. The results of the present study are compared with those reported for stations in the American longitudes.