A new dynamic fluid‐kinetic model for plasma transport within the plasmasphere

The objective of this paper is the application of a newly developed flux-corrected transport based hydrodynamic solution methodology to the plasmasphere refilling problem following a geomagnetic storm. The flux-corrected transport method is extremely well-suited to the solution of nonlinear partial differential equations with shocks and discontinuities. In this solution methodology, every ion species is modeled as two separate fluids originating from the northern and southern hemispheres. We present refilling results that include three ion (H + , He + , and O + ) species and two neutrals (H and O). We believe that with additional modifications, the model can be adapted to the solution of other ionosphere-magnetosphere coupling problems. Plain Language SummaryThe paper applies a newly developed multispecies hydrodynamic model to the plasmasphere refilling problem following geomagnetic storms. We believe that with additional development, the model can be applied to other ionosphere-magnetosphere coupling problems. Key Points:• Developed a hydrodynamic model for the plasmasphere refilling problem following geomagnetic storms • The model is based on the well-known flux-corrected transport method • The model is applied to the plasmasphere refilling problem for three ion species and two neutrals along the L = 4 line Figure 9. (a) Ambipolar electric field profile after 20 min. (b) Ambipolar electric field profile after 2 hr. (c) Ambipolar electric field profile after 15 hr. (d) Ambipolar electric field profile after 40 hr.

Section: Discussion Of Resultsmentioning

confidence: 99%

A Multiion, Flux‐Corrected Transport Based Hydrodynamic Model for the Plasmasphere Refilling Problem

Chatterjee

Schunk

2020

“…Besides the plasma‐neutral collisions, Coulomb collisions between the charged particles can also change the plasma velocity distributions in the parallel and perpendicular directions [ Nanbu , ] and therefore influence the particle trapping and latitude distribution [ Wilson et al ., ; Wang et al ., ]. The Coulomb collision frequency ( v st ) for the interactions between different ion species ( s and t ) can be expressed as [ Schunk and Nagy , ]

v_{s t} = B_{s t} \frac{n_{t}}{T_{t}^{3 / 2}}

…”

Section: Discussionmentioning

confidence: 99%

“…However, the Coulomb collision frequencies between the light plasma species ( e − , H + , and He + ) with the heavy oxygen ions (O + ) are still high at 670 km. The frequent Coulomb collisions can cause the pitch angle scatterings of the charged particles [ Wang et al ., ].…”

Section: Discussionmentioning

confidence: 99%

“…In the semikinetic approximation, each ion species (O + , H + , and He + ) can be treated as single particles in the weak plasma‐neutral collision region, and the field‐aligned or latitudinal motion of three ion species depends on the field‐aligned electric field, gravitational force, magnetic mirror force, and centrifugal force along the magnetic field lines [ Wang et al ., ]. Based on the field‐aligned motion equations of the charged particles [ Wang et al ., ], the field‐aligned acceleration ( a i || = d v i || /d t ) of each ion species ( i ) is given by

a_{i true| true|} = \frac{q_{i}}{m_{i}} E_{true| true|} - normalg (||, sin I) - \frac{μ_{i}}{m_{i}} \frac{\partial B}{\partial s} + U_{E} \cdot ((), \frac{\partial \overset{b}{true}}{\partial t} + v_{true| true|} \frac{\partial \overset{b}{true}}{\partial s} + U_{E} \cdot \nabla \overset{b}{true})

…”

Section: Discussionmentioning

confidence: 99%

“…In this transition region, different ions (O + , He + , and H + ) and electrons ( e − ) mainly come from the ionization of neutral atmospheric compositions through absorption of solar extreme ultraviolet (EUV) radiation, and some plasma species are also lost through the charge exchange or recombination reactions [ Weiss , ; Schunk and Nagy , ]. Besides the photochemical reactions, the plasma spatial distributions are changed by neutral wind drag and/or electromagnetic forces [ Anderson , ; Murphy et al ., ; Balan et al ., ; Denton et al ., ; Luan and Solomon , ; Wang et al ., ]. Meanwhile, the plasma motions are also influenced by magnetosphere‐ionosphere coupling processes [ Song et al ., , ; Song and Vasyliūnas , ; Tu et al ., ].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Semiannual and solar activity variations of daytime plasma observed by DEMETER in the ionosphere‐plasmasphere transition region

Cao

Yang

et al. 2015

Using the plasma data of Detection of Electro‐Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) satellite and the NRLMSISE‐00 atmospheric model, we examined the semiannual and solar activity variations of the daytime plasma and neutral composition densities in the ionosphere‐plasmasphere transition region (~670–710 km). The results demonstrate that the semiannually latitudinal variation of the daytime oxygen ions (O+) is basically controlled by that of neutral atomic oxygen (O), whereas the latitude distributions of the helium and hydrogen ions (He+ and H+) do not fully depend on the neutral atomic helium (He) and hydrogen (H). The summer enhancement of the heavy oxygen ions is consistent with the neutral O enhancement in the summer hemisphere, and the oxygen ion density has significantly the summer‐dense and winter‐tenuous hemispheric asymmetry with respect to the dip equator. Although the winter enhancements of the lighter He+ and H+ ions are also associated with the neutral He and H enhancements in the winter hemisphere, the high‐density light ions (He+ and H+) and electrons (e−) mainly appear at the low and middle magnetic latitudes (|λ| < 50°). The equatorial accumulations of the light plasma species indicate that the light charged particles (He+, H+, and e−) are easily transported by some equatorward forces (e.g., the magnetic mirror force and centrifugal force). The frequent Coulomb collisions between the charged particles probably lead to the particle trappings at different latitudes. Moreover, the neutral composition densities also influence their ion concentrations during different solar activities. From the low‐F10.7 year (2007–2008) to the high‐F10.7 year (2004–2005), the daytime oxygen ions and electrons increase with the increasing neutral atomic oxygen, whereas the daytime hydrogen ions tend to decrease with the decreasing neutral atomic hydrogen. The helium ion density has no obvious solar activity variation, suggesting that the generation (via the neutral He photoionization) and loss (via the charge exchange with neutral nitrogen N2 and/or the recombination with electrons) of the daytime He+ ions are comparable during different solar activities.

Mass loading at the magnetopause through the plasmaspheric plume

Wang

Song

2016

Self Cite

An investigation of the transport of the plasmaspheric plasma to the dayside magnetopause under disturbed geomagnetic conditions associated with plasmaspheric plumes is conducted by numerical simulations using the Dynamic Fluid‐Kinetic (DyFK) model. The simulations present the field‐aligned density distributions and kinetic features of multiple ion species (H+/He+/O+) in a plasmaspheric flux tube that corotates while convecting toward the dayside magnetopause. The simulations show that the plasmaspheric plume can provide an equatorial magnetopause plasma density which is up to 3 orders of magnitude higher than that under the typical conditions. With the effects of wave‐particle interaction included, such mass loading through the plasmaspheric plume is even stronger. The local reconnection rate at the location where the plasmaspheric plume mass loads at the dayside magnetopause may decrease by 90%, depending on the geomagnetic activities, the outer plasmaspheric density, and the level and spatial span of the wave‐particle interaction.