| 项目编号: | 1613134
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| 项目名称: | Solar Wind Control of Alfven Wave Power in the Polar Region |
| 作者: | Andreas Keiling
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| 承担单位: | University of California-Berkeley
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| 批准年: | 2016
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| 开始日期: | 2016-09-01
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| 结束日期: | 2019-08-31
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| 资助金额: | 256972
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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: | alfven wave
; polar ionosphere
; wave
; reconnection region
; nasa polar spacecraft
; solar wind condition
; polar region
; solar wind
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| 英文摘要: | This project will quantify the global distribution of Alfven waves in the polar region and its variations with solar wind conditions, geomagnetic storm conditions, and auroral substorm phase. Alfven waves are an essential component of the dynamics and associated energy transport within the Earth's magnetosphere. This has become more and more apparent with each satellite mission into the magnetosphere. Significant Alfven wave activity has been observed by satellites traveling through the plasma sheet, the plasmasphere, the tail lobes, the auroral zone, and the reconnection regions in the magnetotail. Alfven waves are oscillations traveling along magnetic field lines. Much like waves moving outward from a stone tossed into the water, the Alfven waves carry information to other locations along magnetic field lines about changes in the magnetic field or currents at the site of their generation. At these other locations, the waves can be dissipated supplying their energy to power different processes remote from the original energy source. For example, in the polar ionosphere, the dissipation of Alfven waves supplies energy to accelerate the electrons responsible for creating breathtaking auroras. These Alfven waves are thought to originate in strong plasma jets within the stretched magnetotail far from the polar ionosphere. The project will support a graduate student for the summer thus contributing to the training of the next generation scientific workforce. The advances in knowledge of an energy transport process important to the dynamics of the magnetosphere will in the long term improve models of space weather forecasting, of value to a technological society.
The project proposed here will develop statistical maps of Alfven wave power observed by the NASA Polar spacecraft and quantify how these maps vary depending on solar wind and interplanetary magnetic field parameters and storm and substorm conditions. Results from MHD modeling will be compared to the statistical maps to validate the MHD simulations. The study will use tools similar to and the methodology of earlier work by the PI, but will include 10 years of data instead of the one-year interval used previously. This will allow the statistical examination of Alfven wave power for a wide-range of different conditions and geomagnetic activity levels. New insights about energy transport and dynamics of the Geospace system are expected. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/91344
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Andreas Keiling. Solar Wind Control of Alfven Wave Power in the Polar Region. 2016-01-01.
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