Evidence for Magnetospheric Effects on the Sodium Atmosphere of Mercury
Evidence for Magnetospheric Effects on the Sodium Atmosphere of Mercury
复制标题
磁层对水星钠气氛影响的证据
作者：
A. Potter;T. Morgan
汞在钠D2发射线的单色图像显示，在北方和南方高纬度地区的局部区域有过量的钠发射，钠发射分布存在着逐日的全球变化。这些现象支持了磁层效应可能是原因的说法。在磁亚暴期间，当磁层离子直接撞击表面时，表面矿物的溅射可能在极地地区产生钠蒸气。另一个重要的过程可能是钠离子沿着磁场线向极地地区的运输，在那里它们直接撞击水星表面并被中和以再生中性钠原子。行星钠分布的日常变化可能是由于太阳活动的变化造成的，太阳活动可以在几个小时的时间尺度内改变磁层。对钠散逸层的观测可能为远程监测水星的磁层提供一种工具。
Monochromatic images of Mercury at the sodium D2 emission line showed excess sodium emission in localized regions at high northern and southern latitudes and day-to-day global variations in the distribution of sodium emission. These phenomena support the suggestion that magnetospheric effects could be the cause. Sputtering of surface minerals could produce sodium vapor in polar regions during magnetic substorms, when magnetospheric ions directly impact the surface. Another important process may be the transport of sodium ions along magnetic field lines toward polar regions, where they impact directly on the surface of Mercury and are neutralized to regenerate neutral sodium atoms. Day-to-day variations in planetary sodium distributions could result from changing solar activity, which can change the magnetosphere in time scales of a few hours. Observations of the sodium exosphere may provide a tool for remote monitoring of the magnetosphere of Mercury.