Journal article
Van Allen Probes Survey of the Plasmasphere and the Inner Magnetosphere Electric Field
Journal of geophysical research. Space physics, Vol.130(8), e2025JA033810
08/2025
DOI: 10.1029/2025JA033810
Abstract
We present a statistical study of the convection electric field and cold plasma density in the inner magnetosphere for different levels of geomagnetic activity over the Van Allen Probes mission. In addition to presenting the average dawn‐to‐dusk component of the electric field, the electric field is also presented in radial and azimuthal components. The statistical state of the plasmasphere is presented and put into the context of the electric field. In the frame corotating with the Earth, a trail of radially outward electric field wraps around from the dusk side regions of strong electric field through the nightside to the dawn side. This electric field feature corresponds to a westward plasma drift. Outside this region of radially outward electric field, in the post‐midnight sector, there is a sharp reversal of the radial electric field to an inward orientation. This feature corresponds to a flow shear in the Earth corotating frame and we suggest it is the Harang discontinuity mapped into the equatorial plane. In the post‐noon sector, the enhanced dawn‐dusk electric field is associated with a significant electric field azimuthal component. This is consistent with the radially outward flow of plasma in the drainage plume. When mapped into the ionosphere, this electric field should be able to lift the F‐region plasma to higher altitudes, where the recombination rate is lower, enhancing density and consequentially increasing the outflow rate. This mechanism could be by directly adding plasma to the plume without having to first journey through the plasmasphere.
Statistical maps produced in L‐MLT of the plasma density and electric field in the inner magnetosphere for different activity levels Radial and azimuthal electric field morphology that relates it to convective and ionospheric processes Results suggest that the electric fields in the plume increase ionospheric outflow to the plume
Details
- Title: Subtitle
- Van Allen Probes Survey of the Plasmasphere and the Inner Magnetosphere Electric Field
- Creators
- Scott Thaller - Orion Space Solutions, an Arcfield Company Louisville CO USACristian P. Ferradas - Goddard Space Flight CenterMei‐Ching Fok - Goddard Space Flight CenterSam Califf - Cooperative Institute for Research in Environmental SciencesSheng Tian - University of California, Los AngelesJean Francois Ripoll - CEA DAM DIF Arpajon France, UPS CEA LMCE Bruyères‐le‐Châtel FranceDavid Hartley - University of IowaJohn R. Wygant - University of Minnesota
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.130(8), e2025JA033810
- DOI
- 10.1029/2025JA033810
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Publisher
- AMER GEOPHYSICAL UNION
- Grant note
- Heliophysics Division: 80NSSC21K0519, 80NSSC20K1324 NASA
We acknowledge NASA funding through the Heliophysics Guest Investigator Open Grant 80NSSC21K0584. ST would like to additionally acknowledge NSF-GEM Grant 2350235 and valuable discussions with Toshi Nishimura on interpretation of the electric field structures. DPH acknowledges support from NSF-GEM Grants 2040708 and 2350235, and NASA Grants 80NSSC21K0519 and 80NSSC20K1324. The authors would like to thank the anonymous reviewer for helpful comments that have improved this manuscript.
- Language
- English
- Date published
- 08/2025
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984946843502771
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