Plasma diffusion in the ionosphere

Chandra, S.

doi:10.1016/0021-9169(64)90112-6

Cited by 19 publications

(5 citation statements)

References 9 publications

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“…We now return to first principles to investigate theories of plasma motion. The momentum equations for each species of charged particle in an ionosphere are [ Chandra , 1964; Banks and Kockarts , 1973]: where t is time, j is an index referring to a charged species, m j is the mass of a particle of species j , v j is the velocity of species j , g is the acceleration due to gravity, N j is the number density of species j , k is Boltzmann's constant, T j is the temperature of species j , q j is the charge of a particle of species j , E is the electric field, B is the magnetic field, ν jn is the “diffusion collision frequency” for collisions between particles of species j and neutrals n , u is the neutral wind velocity, and ν jk is the “diffusion collision frequency” for collisions between charged particles of species j and k . The current density, J , is defined as.…”

Section: Conservation Of Momentummentioning

confidence: 99%

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Theoretical models of ionospheric electrodynamics and plasma transport

Withers

2008

J. Geophys. Res.

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[1] A relationship between J, the current density, and E 0 , the electric field measured in the frame of the neutral wind, is derived for a planetary ionosphere:. If pressure gradients and gravity are neglected, this reduces to the well-known J = E 0 , where is the conductivity tensor. If J = 0, this reduces to ambipolar diffusion. Neither J = E 0 nor ambipolar diffusion can describe the vertical motion of plasma in a dynamo region, a region where electrons are tied to fieldlines, but ions are not. This has prevented models from accurately describing how vertical plasma transport affects plasma densities in the martian ionosphere. The relationship J = Q + S E 0 is applied to a one-dimensional ionospheric model to study ion velocities, electron velocities, currents, electric fields, and induced magnetic fields simultaneously and self-consistently. In this model, ion and electron velocities transition smoothly from moving across fieldlines below the dynamo region to moving along fieldlines above the dynamo region. This relationship is valid for the terrestrial ionosphere; replacing J = E 0 with J = Q + S E 0 in terrestrial models may alter some of their predictions.

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Section: Conservation Of Momentummentioning

confidence: 99%

“…[14] We now return to first principles to investigate theories of plasma motion. The momentum equations for each species of charged particle in an ionosphere are [Chandra, 1964;Banks and Kockarts, 1973]:…”

Section: Conservation Of Momentummentioning

confidence: 99%

Theoretical models of ionospheric electrodynamics and plasma transport

Withers

2008

J. Geophys. Res.

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“…T h i s apparent confusion a r i s e s by comparison of t h e work of Chandra (1964), ( t o be r e f e r r e d t o a s C -I ) , i n which it i s shown t h a t t h e assumption of ambipolar d i f f u s i o n a l o n g a f i e l d l i n e cannot l e a d t o geomagnetic c o n t r o l of t h e charged p a r t i c l e s , and such p a p e r s a s Goldberg and Schmerling (1962, 19631, ( t o be r e f e r r e d t o a s GS-I azd GS-11), and Goldberg, Kendall, and Schmerling (1964), ( t o be r e f e r r e d t o a s GKS), i n which t h i s process does appear t o produce geomagnetic c o n t r o l of t h e charged p a r t i c l e d e n s i t y i n t h e ionos p h e r e .…”

Section: Introduction I N Recent Months I T Has Become I N C R E a Smentioning

confidence: 99%

Geomagnetic control of diffusion in the upper atmosphere

Chandra¹,

Goldberg²

1964

J. Geophys. Res.

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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 .

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“…This is important primarily as regards the study of the ionosphere and terrestrial and cosmic space. For example, diffusion plays an important part in problems dealing with the formation and the shape of ionospheric layers [2][3][4][5][6][7][8][9], clouds of artificial ionization set up by rockets and high-altitude explosions [10][11][12][13][14], the origin and structure of ionospheric inhomogeneities [15][16][17][18], and in particular inhomogeneities in the E layer which result from hydrodynamic turbulence [19,20]. Diffusion processes play a determining part in the formation of trails of meteorites, satellites, and rockets in the ionosphere [21][22][23], as well as in the scattering of radio waves by these trails [24][25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%