GEM: Validating Self-Consistent Inner Magnetospheric Models: Assessing Effects of Uncertainties in Plasma Sheet and Electric Field Boundary Conditions on Simulating Storms
GEM: Validating Self-Consistent Inner Magnetospheric Models: Assessing Effects of Uncertainties in Plasma Sheet and Electric Field Boundary Conditions on Simulating Storms
批准号:
1203195
负责人:
Margaret Chen
金额:
$34.0万
依托单位:
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
项目状态:
已结题
起止时间:
2012-06-15 至 2017-05-31
中文摘要
该项目将审查磁层交叉极帽电位(CPCP)和等离子体片人口中的不确定性,以及这些不确定性如何影响磁暴期间磁层环电流的强度和空间分布。它将检查环的模型和观测之间的不一致在多大程度上可以归因于边界条件的不确定性,而不是其他原因,如模型中缺少物理过程。以往的模拟研究表明,作为环电流的主要来源,磁层对流电场和等离子体片分布的变化对环电流有很大的影响。因此,能否成功模拟常见的环电流观测数据,如DST指数、地磁摄动和地球同步轨道上的磁场,以及等离子体参数,取决于对CPCP和等离子体片密度和温度的了解。由于这些量的现场测量的空间和时间分辨率有限,统计再分析或经验模型的平均值经常被用来说明内部磁层模型的边界条件。然而,与这些边界条件规范相关的不确定性很大。该项目将量化模拟的风暴对CPCP以及自洽内部磁层模型的离子和电子等离子体片密度和温度边界条件的不确定性的敏感性。方法是研究由NASA THEMIS航天器和CPCP(国防气象卫星计划)测量的等离子体片参数相对于通常用于提供模拟边界条件的参考模型的统计变化。对于这些数据集,将建立CPCP和中心等离子体片参数参考模型的残差统计模型。将计算多变量误差协方差统计,并将产生等离子体和电场边界条件的蒙特卡罗情景。在某些情况下,蒙特卡罗方案将受到可用现场数据的限制。对于不同的边界条件,将使用磁电自洽赖斯对流模型平衡(RCM-E)来模拟地球同步轨道上的DST、地磁摄动以及磁场和等离子体参数。通过比较不同边界条件场景的度量标准,该项目将确定RCM-E在边界条件中的不确定性下是否物理上足够,或者它是否需要额外的物理过程。该项目将有助于确定研究人员是否需要继续专注于为环电流模型添加更真实的物理特性,或者他们是否应该将重点转移到改善边界条件规范以控制模型。最终,它将为产生整体空间天气、近景预报和预报磁层内部的等离子体和磁场铺平道路。该项目由一位女科学家领导,还涉及产业界(航空航天公司)之间的研究联系。和大学。
英文摘要
This project will examine the uncertainties in the magnetospheric cross polar cap potential (CPCP) and in the plasma sheet population and how these uncertainties affect the intensity and spatial distribution of the magnetospheric ring current during magnetic storms. It will examine how much of the disagreements between models and observations of the ring can be attributed to the uncertainty in the boundary conditions rather than other causes such as missing physical processes in the models. Previous simulation studies have shown that changes in the magnetospheric convection electric field and the plasma sheet distribution, which is the major source to the ring current, strongly influence the ring current. For this reason, success in modeling common ring current observables, such as the Dst index, ground magnetic perturbations and magnetic field at geosynchronous orbit, and plasma parameters is dependent on knowing the CPCP and the plasma sheet densities and temperatures. Because of limited spatial and temporal resolution of in-situ measurements of such quantities, averages from statistical re-analysis or empirical models are often used to specify the boundary conditions for inner magnetospheric models. However, there are large uncertainties associated with these boundary condition specifications. This project will quantify how sensitive simulated storms are to the uncertainties in the CPCP and in the ion and electron plasma sheet density and temperature boundary conditions of self-consistent inner magnetospheric models. The approach is to investigate the statistical variations of plasma sheet parameters measured by the NASA THEMIS spacecraft and the CPCP from DMSP (Defense Meteorological Satellite Program) measurements relative to reference models commonly used to provide simulation boundary conditions. For these data sets, a statistical model of the residual errors of reference models for CPCP and central plasma sheet parameters will be developed. The multivariate error covariance statistics will be computed and Monte Carlo scenarios of the plasma and electric field boundary conditions will be generated. In some cases, the Monte Carlo scenarios will be constrained by available in-situ data. For the different boundary conditions scenarios, the magnetically and electrically self-consistent Rice Convection Model-Equilibrium (RCM-E) will be used to simulate Dst, ground magnetic perturbations and magnetic field and plasma parameters at geosynchronous orbit. By comparing the metrics for the different boundary condition scenarios, the project will determine whether the RCM-E is physically sufficient given the uncertainties in the boundary conditions, or whether it needs additional physical processes.This project will help determine whether researchers need to continue to focus on adding more realistic physics to models of the ring current or if they should shift their focus toward improving the specification of the boundary conditions the control the models. Ultimately it will pave the way to generating ensemble space weather nowcasts and forecasts of the inner magnetosphere's plasma and fields. The project is headed by a woman scientist and also involves research ties between industry (Aerospace Corp.) and universities.
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GEM: Diffuse and Discrete Auroral Electron Precipitation Effects On Magnetosphere-Ionosphere Coupling
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批准号:2225405
-
项目类别:Continuing Grant
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资助金额:$55.8万
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财政年份:2022
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负责人:Margaret Chen
-
依托单位:
GEM: Assessing the Relative Importance of Convection and Induced Electric Fields for Particle Transport and Energization in the Inner Magnetosphere
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批准号:1602862
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项目类别:Continuing Grant
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资助金额:$34.2万
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财政年份:2017
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负责人:Margaret Chen
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依托单位:
GEM: Simulations of Diffuse Auroral Electron Transport and Precipitation in Realistic Model Storms and Substorms
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批准号:0902832
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项目类别:Continuing Grant
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资助金额:$30.0万
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财政年份:2009
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负责人:Margaret Chen
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依托单位:
Collaborative Research: Self-Consistent Ring-Current Particle Transport Simulations
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批准号:0548715
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项目类别:Continuing Grant
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资助金额:$22.5万
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财政年份:2006
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负责人:Margaret Chen
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依托单位:
Collaborative Research: GEM--Stormtime Particle Transport Studies in More Realistic Models of the Inner Magnetosphere
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批准号:0202108
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项目类别:Continuing Grant
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资助金额:$14.1万
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财政年份:2002
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负责人:Margaret Chen
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依托单位:
Collaborative Research: Space Weather--Self-Consistent Modeling of Inner Magnetosphere Under Enhanced Convections
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批准号:0207160
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项目类别:Continuing Grant
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资助金额:$10.0万
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财政年份:2002
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负责人:Margaret Chen
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依托单位:
GEM: Modeling the Stormtime Injection of Ring Current Ions and Electrons
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批准号:9900981
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项目类别:Continuing Grant
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资助金额:$22.5万
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财政年份:1999
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负责人:Margaret Chen
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依托单位:
Dynamical Model of Stormtime Ring Current
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批准号:9522288
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项目类别:Continuing Grant
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资助金额:$16.0万
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财政年份:1995
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负责人:Margaret Chen
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依托单位:
海外基金