O+ ion temperature partition coefficients β∥ and β⊥: The Effect of O+–O+ Coulomb self‐collisions

Barghouthi, I. A.

doi:10.1029/2004ja010475

Cited by 2 publications

(1 citation statement)

References 29 publications

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“…The value of is not a constant, but varies with altitude and ionospheric conditions. Monte Carlo simulations [ Winkler et al , 1992; Barghouthi , 2005] and experiments [ McCrea et al , 1993, 1995] reported values and profiles ranging from 0.22 [ Winkler et al , 1992] to 0.5 [ Barghouthi , 2005] for an electric field of 50 mV near 300 km, corresponding to an ion drift speed of ≈1000 m/s. = = 2/3 corresponds to no anisotropy, and and then become identical to .…”

Section: Discussionmentioning

confidence: 99%

On the relationship between flux transfer events, temperature enhancements, and ion upflow events in the cusp ionosphere

2011

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[1] A transit of the dayside aurora across the field-of-view of the EISCAT Svalbard Radar occurred on 20 December 1998. This offered an excellent opportunity to study the spatial structure of the cusp/cleft aurora using meridian scanning photometer and incoherent scatter radar. We were able to identify distinct regions of upflow driven by ion heating (type 1) and upflow driven by electron heating (type 2) around poleward moving auroral forms, a transient auroral feature tied to flux transfer events. A quiet period before the auroral transit allowed us to estimate a neutral temperature profile, which enabled calculation of the ion-neutral relative wind. We found evidence for purely ion heating-driven upflow equatorward of the cusp auroral boundary, and for electron heating-driven upflow near the equatorward auroral boundary. The greatest upflow occurred near the center of the cusp aurora when both ion and electron temperatures were enhanced. The observed upflows were greater than expected from ambipolar diffusion alone, suggesting that ion-neutral frictional heating did contribute to upflow events in most cases. The great variability observed in ion temperature indicates that the ion flow was greatly structured within the aurora. Type 1-2 upflows may be considered as spatial structures of active cusp. Upflows are observed at various times in their evolution, and one upflow event, estimated to be 5-10 minutes old, showed a lifting of the F region of some 100 km, indicating a hybrid of type 1 and type 2.Citation: Skjaeveland, Å., J. Moen, and H. C. Carlson (2011), On the relationship between flux transfer events, temperature enhancements, and ion upflow events in the cusp ionosphere,

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Section: Discussionmentioning

confidence: 99%

On the relationship between flux transfer events, temperature enhancements, and ion upflow events in the cusp ionosphere

2011

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Hypergeometric function representation of transport coefficients for drifting bi-Maxwellian plasmas

Jubeh

Barghouthi

2017

Physics of Plasmas

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We derive the momentum, parallel energy, and perpendicular energy collisional transport coefficients for drifting bi-Maxwellian plasmas by using the Boltzmann collision integral approach and present them in the form of triple hypergeometric functions. In the derivation, we write the drift velocity u of the bi-Maxwellian plasma in terms of parallel and perpendicular components (i.e., u = u‖ + u⊥), parallel and perpendicular with respect to the ambient magnetic field, and we consider the Coulomb collision interactions. We consider two special cases: first, when the drift velocity is parallel to the ambient magnetic field (i.e., u = u‖), and second, when the drift velocity is perpendicular to the ambient magnetic field (i.e., u = u⊥). For the first case, the transport equations and consequently the transport coefficients are derived and presented in the form of double hypergeometric functions; these results are consistent with the findings of Hellinger and Trávníček [Phys. Plasmas 16(5), 054501 (2009)]. For the second case, the transport coefficients are obtained and found to be in the form of double hypergeometric functions. When we combine these two special cases, i.e., for general u, the transport coefficients are shown to be in the form of triple hypergeometric functions. Also, we investigate the above problem by using another approach, i.e., Fokker Planck approximation. We obtain similar results for both approaches.

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O⁺ ion temperature partition coefficients β_∥ and β_⊥: The Effect of O⁺–O⁺ Coulomb self‐collisions

Cited by 2 publications

References 29 publications

On the relationship between flux transfer events, temperature enhancements, and ion upflow events in the cusp ionosphere

On the relationship between flux transfer events, temperature enhancements, and ion upflow events in the cusp ionosphere

Hypergeometric function representation of transport coefficients for drifting bi-Maxwellian plasmas

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