Polar/TIDE Results on Polar Ion Outflows
Polar/TIDE Results on Polar Ion Outflows
复制标题
极性离子流出的 Polar/TIDE 结果
DOI：
10.1029/gm109p0087
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Y. Su
中科院分区：
文献类型：
--
作者：
T. Moore;M. Chandler;C. Chappell;R. H. Comfort;P. Craven;D. Delcourt;H. Elliott;B. Giles;J. Horwitz;C. Pollock;Y. Su
ISTP极地航天器配备了一种独特的等离子体速度分析器系统，专门为低能量、低密度等离子体离子的动力学诊断而设计。这种等离子体以前在极帽区域是看不到的，因为它们的速度很低，而且航天器在低环境等离子体密度的阳光下会产生正的光电荷。热离子动力学实验(TEDE)包括七个大孔，聚焦静电光学和飞行时间质量分析，以增强对低能等离子体离子的敏感性。等离子体源仪器在小电势(∼+2V)下限制和调节极地航天器的光电荷。TEDER和PSI共同产生了对以下方面的新观测：1)裂隙地区太阳和电离层等离子体的混合；2)极光加热和等离子体输送；3)极冠电离层的太阳照明控制；4)整个极帽地区较低高度的O+向下运动；5)高海拔极风；6)极地外流的高空对流；7)极风外流的意外动力；以及8)等离子体供应给等离子体片。这些观测结果表明，大多数极冠O+外流起源于日侧等离子体上升流区，在极帽中产生了等离子体喷泉效应。这些观测结果支持评估电离层等离子体源对磁层动力学和风暴现象的影响。初步的全球模拟结果表明，电离层等离子体是延伸到中央等离子体片中持续中性线的相应地理顶层内等离子体密度和气压的主要贡献者。潮汐和PSI从根本上帮助我们了解到，太阳风能的耗散并不局限于电离层本身，而是分布在以陆地为主的更大的地圈中。
The ISTP Polar spacecraft is equipped with a unique plasma velocity analyzer system designed specifically for kinetic diagnostics of low-energy, low-density plasma ions. Such plasmas were previously unobservable in the polar cap region owing to their low velocities and the positive photoelectric charging of spacecraft in sunlight at low ambient plasma density. The thermal ion dynamics experiment (TIDE) incorporates seven large apertures, focusing electrostatic optics, and time-of-flight mass analysis, for enhanced sensitivity to low energy plasma ions. The plasma source instrument (PSI) limits and regulates the photoelectric charging of the Polar spacecraft at small potentials (∼+2V). Together, TIDE and PSI have produced new observations of i) the mixing of solar and ionospheric plasmas in the cleft regions; ii) auroral heating and plasma transport; iii) solar illumination control of the polar cap ionosphere; iv) the downward motion of O + at lower altitudes throughout the polar cap region; v) the high altitude polar wind; vi) the high altitude convection of the polar outflows; vii) the unexpected dynamism of polar wind outflows; and viii) the supply of plasma to the plasma sheet. These observations indicate that most polar cap O + out flow originates in the dayside plasma upwelling region, creating a plasma fountain effect in the polar cap. The observations support the evaluation of consequences of the ionospheric source of plasma for magnetospheric dynamics and storm phenomena. Preliminary global modeling results indicate that ionospheric plasma is the dominant contributor to both the density and pressure of the plasma within a corresponding geopause that extends to the persistent neutral line in the central plasma sheet. TIDE and PSI have contributed fundamentally to our knowledge that the dissipation of solar wind energy is not limited to the ionosphere proper, but is distributed throughout a much larger geosphere of dominantly terrestrial origin.