| 项目编号: | 1559717
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| 项目名称: | EAGER: Transformative Modeling Studies of Magnetosphere-Ionosphere/Thermosphere System |
| 作者: | Paul Song
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| 承担单位: | University of Massachusetts Lowell
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| 批准年: | 2014
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| 开始日期: | 2015-12-15
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| 结束日期: | 2017-11-30
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| 资助金额: | USD296683
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| 资助来源: | US-NSF
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| 项目类别: | Continuing grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Atmospheric and Geospace Sciences
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| 英文关键词: | upper atmosphere
; magnetic field
; eager program
; gps navigation system
; earth
; model
; global magnetosphere-ionosphere model
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| 英文摘要: | The space environment surrounding the Earth is extremely dynamic, responding rapidly to the changing plasma and electromagnetic fields arriving from the Sun. Storms in space can trigger explosively (like earthquakes and volcanoes), driving strong electric currents through the upper atmosphere, which induce currents in the solid earth that can disrupt power grids; redistributing the charged particles within the embedded layers of the ionosphere, which can interfere with GPS navigation systems; and heating the upper atmosphere, which increases drag degrading the orbits of satellites. Global models of the high-altitude geospace environment are electromagnetic in nature and can follow these rapid changes in the magnetic fields and currents surrounding Earth, not so models of the magnetically coupled lower altitude ionosphere/upper atmosphere, which are electrostatic in nature. This proposal is focused on the development of a first-of-its-kind global electromagnetic model of the ionosphere/upper atmosphere system that, if successful will ultimately be incorporated into next-generation space weather models. This project is appropriate for the EAGER program. It is high risk but the reward, if it succeeds, is a new generation of global magnetosphere-ionosphere models that could potentially change views on some of the most fundamental aspects of the coupling between space and the upper atmosphere during the rapid onset of disturbances and possibly trigger new discoveries by supplying predictions of other effects to search for in the observations. The results will ultimately improve capabilities for space weather prediction and are potentially of interest to the study of planetary atmospheres, accretion disks, nebula, and the interstellar medium. The training of a graduate student at the University of Massachusetts-Lowell on this grant is an excellent means of transferring knowledge about this complex numerical methodology to the next generation of space scientists and is a near-term broader impact.
Present models of the ionosphere-thermosphere assume that the magnetic field close to Earth is constant. But fast time-scale processes like explosive auroral activity are not correctly represented unless the changes in the magnetic field produced by electric currents closing through the ionosphere are solved for self-consistently. A major impediment to developing such a model using present explicit numerical algorithms has been the intractably short time steps (as short as 1 millionth of a second at 100 kilometers altitude) required to maintain stability of the solution, which dictate unrealistically long computer run times in order to follow the evolution of the system. The PI is implementing new numerical technology not widely known in the geospace community based on implicit algorithms that enable the use of much longer time steps, and also optimizing the model to run on high-performance computers. The new electromagnetic model will then be used in a number of numerical experiments to explore controversial features of rapidly developing disturbances in the coupled geospace - upper atmosphere system. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/93018
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Paul Song. EAGER: Transformative Modeling Studies of Magnetosphere-Ionosphere/Thermosphere System. 2014-01-01.
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