Behavior of ionized plasma in the high latitude topside ionosphere: The polar wind

Ganguli, Supriya B.; Mitchell, H. G.; Palmadesso, P. J.

doi:10.1016/0032-0633(87)90030-4

Cited by 69 publications

(40 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The classical theory of polar wind, without ponderomotive forces by Alfvén waves in the flow, was developed by Banks andHolzer (1968, 1969), Lemaire and Scherer (1973), Schunk and Watkins (1979, 1981, Ganguli et al (1987Ganguli et al ( , 1988, Schunk (1989), Schunk and Sojka (1997), and Ganguli (1996). The supersonic outflow of plasma from the ionosphere into the tail of the magnetosphere along open geomagnetic field lines bare many similarities with the solar wind, a theory that was proposed by Parker (1963).…”

Section: Statement Of the Problem And Basic Equationsmentioning

confidence: 99%

Ponderomotive Forces in Cosmos

Lundin

Guglielmi

2006

Space Sci Rev

View full text Add to dashboard Cite

This review is devoted to ponderomotive forces and their importance for the acceleration of charged particles by electromagnetic waves in space plasmas. Ponderomotive forces constitute timeaveraged nonlinear forces acting on a media in the presence of oscillating electromagnetic fields. Ponderomotive forces represent a useful analytical tool to describe plasma acceleration. Oscillating electromagnetic fields are also related with dissipative processes, such as heating of particles. Dissipative processes are, however, left outside these discussions. The focus will be entirely on the (conservative) ponderomotive forces acting in space plasmas. The review consists of seven sections. In Section 1, we explain the rational for using the auxiliary ponderomotive forces instead of the fundamental Lorentz force for the study of particle motions in oscillating fields. In Section 2, we present the Abraham, Miller, Lundin-Hultqvist and Barlow ponderomotive forces, and the Bolotovsky-Serov ponderomotive drift. The hydrodynamic, quasihydrodynamic, and "test-particle" approaches are used for the study of ponderomotive wave-particle interaction. The problems of self-consistency and regularization are discussed in Section 3. The model of static balance of forces (Section 4) exemplifies the interplay between thermal, gravitational and ponderomotive forces, but it also introduces a set of useful definitions, dimensionless parameters, etc. We analyze the Alfvén and ion cyclotron waves in static limit with emphasis on the specific distinction between traveling and standing waves. Particular attention has been given to the impact of traveling Alfvén waves on the steady state anabatic wind that blows over the polar regions (Section 5). We demonstrate the existence of a wave-induced cold anabatic wind. We also show that, at a critical point, the ponderomotive acceleration of the wind is a factor of 3 greater than the thermal acceleration. Section 6 demonstrates various manifestations of ponderomotive forces in the Earth's magnetosphere, for instance the ionospheric plasma acceleration and outflow. The polar wind and the auroral density cavities are considered in relation to results from the Freja and Viking satellites. The high-altitude energization and escape of ions is discussed. The ponderomotive anharmonicity of standing Alfvén waves is analyzed from ground based ULF wave measurements. The complexity of the many challenging problems related with plasma processes near the magnetospheric boundaries is discussed in the light of recent Cluster observations. At the end of Section 6, we consider the application of ponderomotive forces to the diversity of phenomena on the Sun, in the interstellar environment, on newborn stars, pulsars and active galaxies. We emphasize the role of forcing of magnetized plasmas in general and ponderomotive forcing in particular, presenting some simple conceivable scenarios for massive outflow and jets from astrophysical objects.

show abstract

Section: Statement Of the Problem And Basic Equationsmentioning

confidence: 99%

Ponderomotive Forces in Cosmos

Lundin

Guglielmi

2006

Space Sci Rev

View full text Add to dashboard Cite

show abstract

“…A number of models of the polar wind have been proposed; hydrodynamic models Holzer, 1968, 1969a, b;Marubashi, 1970;Raitt et al, 1975Raitt et al, , 1977Schunk et al, 1978), kinetic models Scherer, 1970, 1973), models solving the generalized transport equations Watkins, 1981, 1982;Demars and Schunk, 1987;Ganguli et al, 1987) and time-dependent models (Gombosi and Nagy, 1989;Schunk and Sojka, 1989). Polar wind observations are dated from the early years of the 1970s with the Explorer 31, OGO 2, and ISIS 2 satellites (Homan, 1970;Taylor and Walsh, 1972;Homan et al, 1974) and in the 1980s case studies of the polar wind were carried out based on data obtained from the Dynamic Explorer (DE) 1 satellite (Shelley et al, 1982;Nagai et al, 1984;Chandler et al, 1991).…”

Section: Introductionmentioning

confidence: 99%

Ion upflow and downflow at the topside ionosphere observed by the EISCAT VHF radar

et al. 2000

View full text Add to dashboard Cite

Abstract. We have determined the MLT distribution and K P dependence of the ion up¯ow and down¯ow of the thermal bulk oxygen ion population based on a data analysis using the EISCAT VHF radar CP-7 data obtained at Tromsù during the period between 1990 and 1996: (1) both ion up¯ow and down¯ow events can be observed at any local time (MLT), irrespective of dayside and nightside, and under any magnetic disturbance level, irrespective of quiet and disturbed levels; (2) these up¯ow and down¯ow events are more frequently observed in the nightside than in the dayside; (3) the up¯ow events are more frequently observed than the down¯ow events at any local time except midnight and at any K P level and the dierence of the occurrence frequencies between the up¯ow and down¯ow events is smaller around midnight; and (4) the occurrence frequencies of both the ion up¯ow and down¯ow events appear to increase with increasing K P level, while the occurrence frequency of the down¯ow appears to stop increasing at some K P level.

show abstract

“…The partitioning of the ion distribution allows the O ion distribution to become anisotropic according to equations given in, for example, Ganguli et al (1987) and Gombosi and Rasmussen (1991). The isotropic temperature, which is output from the model for H Y He and electrons, is calculated from the energy Bailey and Sellek (1990).…”

Section: Anisotropic Codementioning

confidence: 99%

Localized structure in the cusp and high-latitude ionosphere: a modelling study

1999

View full text Add to dashboard Cite

Abstract. The ionospheric signature of a¯ux transfer event (FTE) seen in EISCAT radar data has been used as the basis for a modelling study using a new numerical model of the high-latitude ionosphere developed at the University of Sheeld, UK. The evolution of structure in the high-latitude ionosphere is investigated and examined with respect to the current views of polar patch formation and development. A localized velocity enhancement, of the type associated with FTEs, is added to the plasma as it passes through the cusp. This is found to produce a region of greatly enhanced ion temperature. The new model can provide greater detail during this event as it includes anisotropic temperature calculations for the O ions. This illustrates the uneven partitioning of the energy during an event of this type. O ion temperatures are found to become increasingly anisotropic, with the perpendicular temperature being substantially larger than the parallel component during the velocity enhancement. The enhanced temperatures lead to an increase in the recombination rate, which results in an alteration of the ion concentrations. A region of decreased O and increased molecular ion concentration develops in the cusp. The electron temperature is less enhanced than the ions. As the new model has an upper boundary of 10 000 km the topside can also be studied in great detail. Large upward¯uxes are seen to transport plasma to higher altitudes, contributing to the alteration of the ion densities. Plasma is stored in the topside ionosphere and released several hours after the FTE has ®nished as the¯ux tube convects across the polar cap. This mechanism illustrates how concentration patches can be created on the dayside and be maintained into the nightside polar cap.

show abstract

Behavior of ionized plasma in the high latitude topside ionosphere: The polar wind

Cited by 69 publications

References 24 publications

Ponderomotive Forces in Cosmos

Ponderomotive Forces in Cosmos

Ion upflow and downflow at the topside ionosphere observed by the EISCAT VHF radar

Localized structure in the cusp and high-latitude ionosphere: a modelling study

Contact Info

Product

Resources

About