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

地球磁层传输过程中质量载荷效应的测量

• 批准号: 0855924
• 负责人: Ennio Sanchez
• 金额: $ 37.5万
• 依托单位: SRI International
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0855924&HistoricalAwards=false
• 关键词: Measurement; Mass; Loading; Effects; Transport

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.

磁层质量密度的变化可对若干重要的磁层现象产生重大影响。 预计质量负载会影响磁重联的速率，并影响与超低频（ULF）波相关的过程。 质量负荷影响磁层顶和低纬边界层Kelvin-Helmholtz（K-H）振荡的增长率和频率。 虽然这些影响很重要，但很难对质量负荷和相关影响进行定量测量。 该项目将为两类太阳风输入开发一个事件数据库。 在每一种情况下，这一事件的开始都将伴随着一个长期的向北行星际磁场，这将建立磁层的“基态”。将被检查的事件的第一类是共旋相互作用区（CIR）和第二类是长期向南IMF的时期。 将通过统计比较作为磁层密度函数的穿过极帽边界的磁通量的速率来检验质量负荷对向阳面磁合并的影响。 该项目将利用Geotail和THEMIS卫星飞行任务的数据，并结合地面磁力计和非相干散射雷达数据，包括为研究生或高年级本科生开展的研究活动。 这些结果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都很重要。