Measurement of Mass-Loading Effects On Transport Processes in the Earth's Magnetosphere

磁层中质量密度的变化可对一些重要的磁层现象产生重大影响。质量负荷预计会影响磁重联的速率，并影响与超低频(ULF)波相关的过程。在磁层顶和低纬边界层，质量负荷影响开尔文-亥姆霍兹(K-H)振荡的增长速度和频率。尽管这些影响很重要，但很难对质量负荷及其相关影响进行量化衡量。该项目将为两类太阳风输入建立一个事件数据库。在每一种情况下，该事件都将从向北的行星际磁场(IMF)的较长时间开始，这将建立磁层的“基态”。将研究的第一类事件是协旋相互作用区(CIR)，第二类事件是长期向南移动的IMF。通过统计比较穿过极冠边界的磁通量速率作为磁层密度的函数，来检验日侧磁合并的质量负荷效应。该项目将使用来自GeoTail和THEMIS卫星飞行任务的数据，以及地面磁力计和非相干散射雷达数据。该项目将包括研究生或高级本科生的研究活动。这一结果将对地球空间环境建模计划以及我们对空间天气事件的理解和预测能力具有重要意义。

Variations in the mass density in the magnetosphere can have significant effects on a number of important magnetospheric phenomena. Mass loading is expected to effect the rate of magnetic reconnection and it effects the processes related to Ultra-Low Frequency (ULF) waves. Mass loading effects the growth rate and frequency of Kelvin-Helmholtz (K-H) oscillations at the magnetopause and in the low latitude boundary layer (LLBL). Although the effects are important, it has been difficult to get a quantitative measure of the mass loading and the associated effects. This project will develop a database of events for two classes of solar wind inputs. In each case, the event will begin with a prolonged period of northward interplanetary magnetic field (IMF), which will establish a "ground-state" of the magnetosphere. The first class of events that will be examined is Corotating Interaction Regions (CIRs) and the second class is periods of prolonged southward IMF. The mass loading effect on dayside magnetic merging will be examined by statistically comparing the rate of magnetic flux crossing the polar cap boundary as a function of the magnetospheric density. The project will use data from the Geotail and THEMIS satellite missions in conjunction with ground-based magnetometers and incoherent scatter radar data.The project will include research activities for a graduate student or advanced undergraduate student. The results will be of importance to the Geosapce Environment Modeling program as well as to our understanding and ability to forecast space weather events.