Meridional Distribution of Middle‐Energy Protons and Pressure‐Driven Currents in the Nightside Inner Magnetosphere: Arase Observations
Meridional Distribution of Middle‐Energy Protons and Pressure‐Driven Currents in the Nightside Inner Magnetosphere: Arase Observations
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DOI：
10.1029/2019ja026682
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发表时间：
2019-07
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通讯作者：
S. Imajo;M. Nosé;S. Kasahara;S. Yokota;A. Matsuoka;K. Keika;T. Hori;M. Teramoto;K. Yamamoto;S. Oimatsu;R. Nomura;A. Fujimoto;I. Shinohara;Y. Miyoshi
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作者：
S. Imajo;M. Nosé;S. Kasahara;S. Yokota;A. Matsuoka;K. Keika;T. Hori;M. Teramoto;K. Yamamoto;S. Oimatsu;R. Nomura;A. Fujimoto;I. Shinohara;Y. Miyoshi
我们利用ARASE卫星的资料，研究了中等扰动时间下，中能质子(10-180keV)和压力驱动电流在夜间(当地时间20-04小时)环电流区的平均经向分布。由于ARASE卫星具有31°的大倾角轨道，它覆盖的磁纬度范围为−40°到40°，径向距离为~lt；6RE。我们发现，随着MLAT的增加，等离子体压力显著降低。同一L壳层在30°和40°时的等离子体压力是0°和4 mm；10°时的∼10-60%，且在较低的L壳层上下降的速度更大。压力各向异性由垂直压力除以平行压力减1得到，随着径向距离的增加而减小，且与MLAT的相关性较弱。30°时血浆β的大小
We examined the average meridional distribution of middle‐energy protons (10–180 keV) and pressure‐driven currents in the nightside (20–04 hr magnetic local time) ring current region during moderately disturbed times using the Arase satellite's data. Because the Arase satellite has a large inclination orbit of 31°, it covers the magnetic latitude (MLAT) in the range of −40° to 40° and a radial distance of <6RE. We found that the plasma pressure decreased significantly with increasing MLAT. The plasma pressure on the same L* shell at 30° < MLAT < 40° was ∼10–60% of that at 0° < 4 MLAT < 10°, and the rate of decrease was larger on lower L* shells. The pressure anisotropy, derived as the perpendicular pressure divided by the parallel pressure minus 1, decreased with radial distance and showed a weak dependence on MLAT. The magnitude of the plasma beta at 30°