A Study of the Solar Wind Ion and Electron Measurements From the Magnetospheric Multiscale Mission's Fast Plasma Investigation
A Study of the Solar Wind Ion and Electron Measurements From the Magnetospheric Multiscale Mission's Fast Plasma Investigation
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磁层多尺度任务快速等离子体调查的太阳风离子和电子测量研究
DOI：
10.1029/2021ja029784
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
C. Pollock
中科院分区：
文献类型：
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作者：
O. Roberts;R. Nakamura;V. Coffey;D. Gershman;M. Volwerk;A. Varsani;B. Giles;J. Dorelli;C. Pollock
我们比较了磁层多尺度使命（MMS）的快速等离子体调查（FPI）和OMNI在地球-太阳L1拉格朗日点附近获得的太阳风中的等离子体测量结果。FPI是一种用于研究等离子体过程的仪器，如磁场重联、加速和湍流。自2017年以来，MMS支持太阳风活动，与MMS主要感兴趣的区域相比，等离子体可以具有更高的马赫数，更低的温度和更窄的光束。随着FPI的固件现在针对这些活动进行了优化，与OMNI的比较有助于解释太阳风测量结果。通过这些比较，我们可以为快速和突发勘测遥测模式提出建议。从快模间隔，我们发现，首先，FPI离子密度可以低于OMNI质子密度。然而，FPI电子密度与OMNI质子密度吻合良好。第二，由于太阳风的质子温度较低且角度较窄，FPI离子温度被高估。因此，建议将OMNI质子温度用于等离子体参数，例如离子β，离子热与磁压力的比率。第三，当与OMNI质子速度相比时，FPI离子速度被很好地估计。在突发模式下，离子密度和温度具有相似的特性，但程度较低。本文讨论的方法减少了在这些等离子体瞬间观测到的自旋效应。结果汇总在一个表格中，其中包括线性拟合参数及其定义的误差。
We compare plasma measurements in the solar wind between the Magnetospheric MultiScale Mission's (MMS) Fast Plasma Investigation (FPI) and those obtained near the Earth‐Sun L1 Lagrangian point from OMNI. FPI is an instrument designed to investigate plasma processes such as magnetic reconnection, acceleration, and turbulence. Since 2017, MMS supports solar wind campaigns where the plasma can have a higher Mach number, a cooler temperature, and a narrower beam compared with the MMS primary regions of interest. With FPI's firmware now optimized for these campaigns, the comparison with OMNI aids the interpretation of solar wind measurements. From these comparisons, we can make suggestions for both fast and burst‐survey telemetry modes. From fast mode intervals, we find first, that the FPI ion density can be lower than the OMNI proton density. However, the FPI electron density agrees well with the OMNI proton density. Second, due to the solar wind's cooler proton temperature and narrow‐angle, the FPI ion temperature is overestimated. Thus, using the OMNI proton temperature is suggested for plasma parameters such as the ion β , the ratio of ion thermal to magnetic pressure. Third, the FPI ion velocity is well‐estimated when compared with the OMNI proton velocity. In burst mode, the ion density and temperature have similar characteristics but to a lesser degree. Spin effects observed in all these plasma moments in burst mode intervals are reduced with the methods discussed in this paper. The results are summarized in a table that includes linear fit parameters and their defined errors.