Geomagnetic control of diffusion in the upper atmosphere

Abstract

In many r e c e n t p a p e r s concerned w i t h providing an explan a t i o n f o r t h e geomagnetic anomaly, agreement w i t h measured d a t a h a s been o b t a i n e d from the e q u a t i o n s of motion f o r elect r o n s and i o n s when used w i t h an e m p i r i c a l boundary c o n d i t i o n , whereas poor agreement has r e s u l t e d from a t t e m p t s t o numeric a l l y i n t e g r a t e t h e commonly employed form of t h e c o n t i n u i t y equation. W e have been a b l e t o e x p l a i n t h i s discrepancy by demonstrating t h a t t h e assumptions used to d e r i v e t h i s f a r m of t h e c o n t i n u i t y e q u a t i o n s do not a g r e e w i t g t o t h e form of t h e e q u a t i o n s used, and found t h a t although f i e l d a l i g n e d d i f f u s i v e e q u i l i br i u m p r o v i d e s t h e correct form, a more r e a s o n a b l e assumption concerning e l e c t r o n and i o n c o l l i s i o n s w i t h n e u t r a l s a l s o l e a d s t o t h e same r e s u l t . W e have then been a b l e t o provide a more r e a l i s t i c t h e o r e t i c a l d e s c r i p t i o n of t h e geomagnetic anomalyby employing a n a n a l y t i c form f o r t h e boundary c o n d i t i o n which is i n better agreement w i t h measurement t h a n those p r e v i o u s l y used F i n a l l y , by combining t h e e q u a t i o n s of motion f o r n e u t r a l s , e l e c t r o n s and i o n s , w e have been a b l e t o i n d i c a t e geomagnetic c o n t r o l f o r t h e n e u t r a l atmosphere i n t h e lower F r e g i o n of t h e ionosphere, a l t h o u g h t h e e x a c t shape of t h i s d i s t r i b u t i o n is unknown .

Relation between Sunspot Number and Charged Particle Density in the Upper Ionosphere

“…Among these probes, the Alouette satellite is the most famous for its study of the top-side ionosphere. Some theories on the profiles of electron density in the top-side ionosphere, geomagnetic control (Chandra and Goldberg 1964) and diffusive equilibrium distribution (Angerami and Thomas 1964), have been shown to be in good agreement with observed data.…”

A review of the theories concerning the equatorial F2 region ionosphere

“…A Chapman-like boundary condition for the vertical electron density profile as the equator was In view of the fact that the observed vertical profile at the equator is only roughly Chapman-like in form, the above results were very encouraging. Next, Chandra and Goldberg (1964) …”

“…In Kendall (1962), Goldberg & Sehmorling (1963), Chandra (1963), Chandra and Goldberg (1964). The last term on the right is the contribution from horizontal electron density gradients and is normally neglected for midlatitude diffusion and drift studies (of.…”

Equatorial geomagnetic anomaly and its associated current system

“…On the other hand, Goldberg et al, [1964] snd Chandra and Goldberg [1964] have studied the isothermal steady-state transport equations for charged fluids moving in a neutral medium (the advantage here being that explicit causes need not be known) and found that they generate, with the appropriate boundaw conditions, accurate representations of the topside geomagnetic anomaly as measured by King et al [1963]. This semiphenomenological approach has also been successful in the upper bottomside F region when the isothermal restriction is lifted [Goldberg, 1965].…”