Comparison of predictive estimates of high‐latitude electrodynamics with observations of global‐scale Birkeland currents
Comparison of predictive estimates of high‐latitude electrodynamics with observations of global‐scale Birkeland currents
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高纬度电动力学的预测估计与全球尺度伯克兰电流的观测结果的比较
DOI：
10.1002/2016sw001529
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
L. Rastaetter
中科院分区：
文献类型：
--
作者：
B. Anderson;H. Korth;D. Welling;V. Merkin;M. Wiltberger;J. Raeder;R. Barnes;C. Waters;A. Pulkkinen;L. Rastaetter
空间气象预报中心地球空间环境建模挑战中的两次地磁暴发生在主动磁层和行星电动力学响应实验首次获得数据之后。我们比较了来自AMPERE的Birkeland电流与2010年4月4日至5日和2011年8月5日至6日风暴的四个模型的预测。这四个模型分别是Weimer（2005 b）场向电流统计模型、里昂-Fedder-Mobarry磁流体动力学（MHD）模拟、开放全球地球空间环流模型MHD模拟和空间天气建模框架MHD模拟。按照Pulkkinen等人（2013）的描述运行MHD模拟，并从社区协调建模中心获得结果。的总径向Birkeland电流，ITotal，和径向电流密度，Jr的分布，为所有模型进行比较与AMPERE的结果。虽然总电流的相关性很好，但数量一致性差异很大。Jr分布揭示了模型与观测结果之间的差异，这些差异与模型中的纬度分布、形态和缺乏夜侧电流系统有关。结果激励增强模拟，首先通过增加模拟分辨率，然后通过检查实施更复杂的电离层电导模型，包括电离层外流或其他省略的物理过程的相对优点。系统的某些方面，包括亚暴时间和位置，可能仍然具有挑战性的模拟，这意味着持续需要真实的时间规范。
Two of the geomagnetic storms for the Space Weather Prediction Center Geospace Environment Modeling challenge occurred after data were first acquired by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). We compare Birkeland currents from AMPERE with predictions from four models for the 4–5 April 2010 and 5–6 August 2011 storms. The four models are the Weimer (2005b) field‐aligned current statistical model, the Lyon‐Fedder‐Mobarry magnetohydrodynamic (MHD) simulation, the Open Global Geospace Circulation Model MHD simulation, and the Space Weather Modeling Framework MHD simulation. The MHD simulations were run as described in Pulkkinen et al. (2013) and the results obtained from the Community Coordinated Modeling Center. The total radial Birkeland current, ITotal, and the distribution of radial current density, Jr, for all models are compared with AMPERE results. While the total currents are well correlated, the quantitative agreement varies considerably. The Jr distributions reveal discrepancies between the models and observations related to the latitude distribution, morphologies, and lack of nightside current systems in the models. The results motivate enhancing the simulations first by increasing the simulation resolution and then by examining the relative merits of implementing more sophisticated ionospheric conductance models, including ionospheric outflows or other omitted physical processes. Some aspects of the system, including substorm timing and location, may remain challenging to simulate, implying a continuing need for real‐time specification.
DOI：
10.1002/2014ja020500
发表时间：
2014-12
期刊：
Journal of Geophysical Research: Space Physics
影响因子：
--
作者：
J. Coxon;S. Milan;Lasse Boy Novock Clausen;Brian J. Anderson;H. Korth
通讯作者：
J. Coxon;S. Milan;Lasse Boy Novock Clausen;Brian J. Anderson;H. Korth