GEM: Generation of Very Low Frequency (VLF) Whistler Waves and Resulting Wave-Particle Interactions in the Radiation Belt

GEM：辐射带中极低频 (VLF) 惠斯勒波的产生以及由此产生的波粒相互作用

• 批准号: 1203739
• 负责人: David Schriver
• 金额: $ 40万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1203739&HistoricalAwards=false
• 关键词: GEM; Generation; Very; Low; Frequency

This project will use a two-dimensional electromagnetic Darwin particle-in-cell simulation determine self-consistently how whistler waves are generated in the magnetosphere for a variety of conditions and to understand the ensuing wave-particle interactions. Non-linear wave-particle and wave-wave interactions are important aspects of this problem necessitating the use of particle in cell simulations. Recent observational and theoretical work has shown that whistler-mode waves can propagate obliquely with respect to the ambient magnetic field, so a multidimensional approach is required. The simulations will be run on a next-generation computational platform that will allow the inclusion of realistic parameters for the radiation belt region and will be used in close coordination with observed wave and particle data to study the growth, amplitudes, and wave propagation characteristics of whistler waves and for chorus waves, the formation of their structured spectra, and the general effects whistlers have on electrons in terms of energization and pitch angle scattering.Whistler waves, which are ubiquitous in the radiation belt region, play a major role in the transport, acceleration and loss of electrons. Whistlers are observed with a variety of characteristics and are sometimes smooth and unstructured, but other times are observed as bursty and structured. The structured and bursty types of emissions are commonly referred to as chorus. Understanding the role waves play in the formation of relativistic electron populations in the radiation belt region is key to space weather studies because of the deleterious effects these electrons can have on satellites. The research program here uses a first principles, self-consistent simulation approach to understand the fundamental problem concerning the origin of VLF whistler waves and the energization of inner-magnetospheric plasmas.

该项目将使用二维电磁darwin粒子模拟，以确定在磁层中如何在各种条件下在磁层中产生惠斯勒波，并了解随后的波颗粒相互作用。非线性波粒和波波相互作用是需要在细胞模拟中使用粒子的重要方面。最近的观察和理论工作表明，惠斯勒模式波可以相对于环境磁场倾斜地传播，因此需要一种多维方法。模拟将在下一代计算平台上运行，该平台将允许包含辐射带区域的现实参数，并将与观察到的波浪和粒子数据密切协调，以研究惠斯勒波和合唱波的生长，振幅和散布的旋转范围和散布的旋转惠斯的范围，并在其结构性效应的范围内形成惠斯的生长，振幅传播特征在辐射带区域无处不在的波浪在电子的传输，加速和损失中起主要作用。观察到吹口哨具有多种特征，有时是光滑且非结构化的，但其他时候则被视为爆发和结构化。 结构化和爆发的排放类型通常称为合唱。了解波浪在辐射带区域形成相对论电子种群中的作用是太空天气研究的关键，因为这些电子对卫星的影响有害。这里的研究计划使用第一原理，即自一致的模拟方法来了解有关VLF惠斯勒波的起源和内部磁层等离子体的能量的基本问题。