Electron cooling in the upper atmosphere

“…Solar EUV and energetic particle heating of electrons is balanced by thermal conduction and by cooling to ions and neutrals. Dalgarno and Degges ( 1968) have shown that the dominant electron cooling process in the lower thermosphere is due to electron impact collisions with the ground state of atomic oxygen which produce transitions among the spin multiplets: the fine structure levels 3 P i , J = 0, 1, 2. A number of analytical formulas for this fine structure cooling rate have appeared: Dalgarno (1969), Lejeune and Petit (1969), and Rees and Roble (1975).…”

Section: Introductionmentioning

confidence: 99%

new fine structure cooling rate

Hoegy

1976

Geophysical Research Letters

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One of the dominant electron cooling processes in the ionosphere is caused by electron impact induced fine structure transitions among the ground state levels of atomic oxygen. This fine structure cooling rate is based on theoretical cross sections. Recent advances in the numerical cross section determinations to include polarization effects and more accurate representations of the atomic target result in new lower values. These cross sections are employed in this paper to derive a new fine structure cooling rate which is between 40% and 60% of the currently used rate. A new generalized formula is presented for the cooling rate (from which the fine structure cooling rate is derived), valid for arbitrary mass and temperature difference of the colliding particles and arbitrary inelastic energy difference.

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“…Выше 200 км основными механизмами охлаждения элек-тронного газа являются кулоновские соударения с ионами, а также возбуждение уровней тонкой структуры атомов кислорода и теплопроводность электронного газа [12,13]. В работах [14,15] …”

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