GEM: Study of Solar Wind-Magnetosphere-Ionosphere Coupling

这项拟议的调查利用ISEE 1号和2号航天器获得的磁场和等离子体的现场观测以及来自IGS磁力计系统链的地面数据，审查了磁层顶上的能量和动量流动。当行星际磁场向南时，将使用垂直于磁层顶表面的磁场和沿磁层顶表面的流动速度来测量跨磁层的平均势降。通过在表面上重复单独测量，可以估计重联场的区域和总的势降。为了确定法向分量，将得到磁层顶三维形状的精确模型。这个模型的压力依赖性将使我们能够测试压力脉冲是否会如所建议的那样引起陨石坑FTE。当IMF向北移动且重联较弱时，仍可通过波动过程进行能量转移。我们将研究从Pc 3到Pc 5周期存在的波，以确定是否有显著的波能通量越过边界。我们将检查来自IGS磁力计的2.5秒分辨率的同步地面数据，以确定这种波能如何通过磁层传播。我们还将研究极光和亚极光区域电流系统对动态气压变化的响应。最后，我们将研究磁层内外的每个边界层，以确定每个边界层如何取决于太阳风条件和磁层顶上的位置，以便确定哪些过程对这些边界层负责。特别是，我们将研究它们的形成是太阳风条件的函数。

This proposed investigation examines energy and momentum flow across the magnetopause using in-situ observations of magnetic field and plasmas obtained by the ISEE 1 and 2 spacecraft and ground based data from the IGS magnetometer chain. The average potential drop across the magnetosphere when the interplanetary magnetic field is southward will be measured using both the magnetic field normal to the magnetopause surface and the flow velocity along the surface. By repeated individual measurements across the surface, both the region of reconnected field and the total potential drop can be estimated. In order to determine the normal component an accurate model of the 3-D shape of the magnetopause will be derived. The pressure dependence of this model will allow us to test if pressure pulses can cause crater FTE's as has been suggested. When the IMF is northward and reconnection is weak, energy transfer can still take place by wave processes. We will examine the waves present from Pc 3 to Pc 5 periods to determine if significant wave energy flux crosses the boundary. We will examine simultaneous ground based data from the IGS magnetometer chain at 2.5s resolution to determine how this wave energy spreads through the magnetosphere. We will also examine the response of auroral and subauroral zone current systems to dynamic pressure changes. Finally, we will examine each of the boundary layers inside and outside the magnetosphere to determine how each of them depends on solar wind conditions and position on the magnetopause in order to determine what processes are responsible for these boundary layers. In particular we will examine their formation as a function of solar wind conditions.