火星弓形激波上游的场对准质子束：首次观测

IF 4.6 1区地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Geophysical Research Letters Pub Date : 2025-05-30 DOI:10.1029/2025GL115483

K. Meziane, C. X. Mazelle, C. Simon-Wedlund, J. S. Halekas, A. M. Hamza, C. Bertucci, D. L. Mitchell, J. R. Espley

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引用次数: 0

摘要

我们报告了MAVEN航天器上的太阳风离子分析仪在火星弓形激波上游约一个火星半径处观测到的快速向太阳传播的高能质子场对准光束（FABs）。速度分布表明，所有光束的整体平行速度v B =（1.35±0.21）。V S ${V}_{B}=(1.35\pm 0.21){V}_{S}$，超过冲击速度V S ${V}_{S}$。在与准平行激波有关的场对准区域观察到几个fab。激波θ Bn ${\theta}_{Bn}$值和光束速度几乎同步变化，排除了镜面反射的可能性，表明存在非镜面反射机制。然而，与地球上的前震波束相比，火星上较慢的前震波束速度仍然无法解释。

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Field-Aligned Proton Beams Upstream of the Martian Bow Shock: First Observations

We report fast sunward-propagating energetic proton field-aligned beams (FABs) observed about one Mars radius upstream of the Martian bow shock, recorded by the Solar Wind Ion Analyzer instrument on the MAVEN spacecraft. The velocity distributions show that all the beams have a bulk parallel speed $v_{B} = (1.35 \pm 0.21) V_{S}$ , exceeding the shock speed $V_{S}$ . Several FABs are observed in the field-aligned region, linked to the quasi-parallel shock. The nearly synchronous variations of shock $θ_{B n}$ values and beam speeds rule out specular reflection, suggesting a non-specular reflection mechanism. However, the slower Martian foreshock beam speeds remain unexplained compared to their terrestrial counterparts.

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来源期刊

Geophysical Research Letters 地学-地球科学综合

CiteScore

9.00

自引率

9.60%

发文量

1588

审稿时长

2.2 months

期刊介绍： Geophysical Research Letters (GRL) publishes high-impact, innovative, and timely research on major scientific advances in all the major geoscience disciplines. Papers are communications-length articles and should have broad and immediate implications in their discipline or across the geosciences. GRLmaintains the fastest turn-around of all high-impact publications in the geosciences and works closely with authors to ensure broad visibility of top papers.