Thermospheric Neutral Winds in the Temperate Latitude Station Delhi

Abstract

Simultaneous time-dependent continuity equations for ions and the equation of motion for ions and neutral particles are solved numerically in the height range of 120-800 km for temperate latitude station (Delhi, 28^.5^oN) and in both the momentum equations; the non-linear acceleration terms are omitted. Wind system Is calculated using Jacchia's model atmosphere [Jacchia, L. G., <i>Smithsonion Contr. Astrophys., </i> 8 (1965b), 215].As compared to earlier workers [Geisler, J. E., <i>J. atmos. terr. Phys., </i> 29(1967),1469; and Kohl, H. &amp; King, J. W., <i>J. atmos. terr. Phys., </i> 29 (1967), 1045],who solved only theneutr.al momentum equation, in this paper the equations have been coupled through ion-neutral collision frequency to take into account the feed-back interaction between the ions and neutral air equations. The horizontal wind velocities vary with height and time, and are of the order of 200 msec^-1 at about 300 km during night and about 120 msec^-1 during daytime for medium solar activity. The zonal wind has a small prevailing eastward component in confirmation with the super-rotation of the upper atmosphere discovered by D. G. King-Hele [<i>Planet. Space Sci., </i> J2 (1964 b), 835], from small changes in the orbital inclination of artificial satellites.