1. Intensification of the Electron Zebra Stripes in the Earth's Inner Magnetosphere During Geomagnetic Storms.
- Author
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Pandya, Megha, Ebihara, Yusuke, Tanaka, Takashi, Manweiler, Jerry W., and Vines, Sarah K.
- Subjects
MAGNETOSPHERE ,ZEBRAS ,STRIPES ,ELECTRONS ,SOLAR wind ,EARTH (Planet) ,MAGNETIC storms ,GEOMAGNETISM - Abstract
We examined rapid variations in the electron zebra stripe patterns, specifically at L = 1.5, over a three‐month duration, using twin Van Allen Probes within Earth's inner magnetosphere. During geomagnetically quiet intervals, these stripes exhibit a peak‐to‐valley ratio (Δj) ∼1.25 in detrended electron fluxes. However, during geomagnetic storms, they became highly prominent, with Δj > 2.5. The correlation between Δj and net field‐aligned currents (FACs) is observed to be high (0.70). Global magnetohydrodynamic (MHD) simulation results indicate that the westward electric field at midnight at low latitudes in the deep inner magnetosphere correlates well with net FACs. An increase in net FACs could amplify the dawn‐to‐dusk electric field in the deep inner magnetosphere, thereby causing the inward transport of electrons. Given that FACs are linked to the interaction between solar wind and the magnetosphere, our findings emphasize the importance of solar wind‐magnetosphere coupling in the deeper regions of the inner magnetosphere. Plain Language Summary: The intensity of hundreds of keV electron fluxes displays a distinctive pattern in the energy versus L‐value spectrogram, characterized by periodic valleys and peaks, commonly referred to as zebra stripes. These patterns have been observed in the magnetospheres of multiple planets, including Earth, Jupiter, and Saturn. Our study reveals that during geomagnetically quiet intervals, Earth's inner magnetospheric zebra stripes exhibit well‐defined banded features. However, these bands become highly pronounced during geomagnetic storms. The peak‐to‐valley ratio (Δj) of detrended electron fluxes shows a correlation with net field‐aligned currents (FACs), and these FACs, in turn, align with the westward component of the electric field at midnight. Consequently, FACs play a significant role in controlling electron flux dynamics deep within the inner magnetosphere. This research illuminates the solar wind‐magnetosphere‐ionosphere couplings. Key Points: Electron zebra stripes are a persistent feature in Earth's inner magnetosphere, although they become intensified during geomagnetic stormsPeak‐valley ratio (Δj) in detrended electron flux within the zebra stripes enhances by ≥1 factor at L = 1.5 during three geomagnetic stormsΔj is well correlated with the net field‐aligned current (FAC) in polar region, suggesting the dominant role of convection driven by FAC [ABSTRACT FROM AUTHOR]
- Published
- 2024
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