| 项目编号: | 1341359
|
| 项目名称: | Structure and Evolution of Dayside Diffuse Aurora and Enhanced Magnetospheric Density Regions from Coordinated Observations of South Pole All-Sky Imager and THEMIS Spacecraft |
| 作者: | Yukitoshi Nishimura
|
| 承担单位: | University of California-Los Angeles
|
| 批准年: | 2013
|
| 开始日期: | 2014-08-01
|
| 结束日期: | 2018-07-31
|
| 资助金额: | USD503257
|
| 资助来源: | US-NSF
|
| 项目类别: | Continuing grant
|
| 国家: | US
|
| 语种: | 英语
|
| 特色学科分类: | Geosciences - Polar
|
| 英文关键词: | density region
; dayside magnetosphere
; diffuse aurora
; whistler-mode wave
; whistler-mode
; aurora-wave-density
; themis spacecraft observation
; source region
; imaging dayside plasma density structure
; m-i
; themis-south pole auroral imager
; plasma density
; satellite observation
; dayside magnetospheric dynamics
; plasma density patch
; dayside density modulation
; structured patch
; ground-based 2d auroral imaging
; dayside conjunction
; antarctic-based auroral observation
; south pole all-sky auroral imager
; dayside magnetospheric density evolution
; south pole
|
| 英文摘要: | Plasma density is one of the fundamental quantities of the magnetosphere-ionosphere (M-I) coupling that affects the growth and propagation of various plasma wave modes, magnetic reconnection rate, and ionospheric conductance; all of which strongly influence energy and mass transport in the M-I system. By taking advantage of simultaneous satellite-ground conjunctions in recent years, this award will help determining the source region of dayside density modulations, specifically addressing three outstanding scientific questions: Where does the enhanced density originate? How do enhanced density regions evolve in time? And what is the typical size of the enhanced density regions?
The plasma density in the dayside magnetosphere is highly structured, and this structure can have a large impact on the excitation of whistler-mode waves that in turn scatter plasma sheet electrons drifting from the nightside and accelerate electrons in the Earth's radiation belts. It has been recently found that whistler-mode waves drive structured patches of the diffuse aurora; this can be used to highlight enhanced density regions in the dayside magnetosphere. The dayside 'aurora-wave-density' correlations lead to questions about the origin of enhanced plasma density patches and their propagation in the dayside magnetosphere. Satellite observations alone have difficulties separating spatial and temporal effects in tracing the motion of enhanced density regions, but ground-based 2D auroral imaging could offer an excellent technique for monitoring the shape and motion of diffuse aurora that is driven by precipitating energetic electrons interacting with whistler-mode waves.
The proposed investigation will use a creative approach for understanding dayside magnetospheric density evolution by using Antarctic-based auroral observations. In particular, South Pole is an ideal dayside auroral observatory due to its longest polar night in the world. The wave-particle interaction producing whistler-mode waves will be used as a tool for imaging dayside plasma density structures using correlated South Pole all-sky auroral imager and THEMIS spacecraft observations. This research may influence not only its own field of diffuse auroral studies, but also related fields such as dayside magnetospheric dynamics, wave particle interactions, and excitation of plasma waves.
This interesting and important scientific research provides an ideal opportunity to train a graduate student, further scientific collaboration and cooperation in Antarctica, and create a list of THEMIS-South Pole auroral imager 'dayside conjunction' events and respective geomagnetic field mapping results for the use by a broader geospace science community. |
| 资源类型: | 项目
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/96293
|
| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
|
|
There are no files associated with this item.
|
| Recommended Citation: | |
Yukitoshi Nishimura. Structure and Evolution of Dayside Diffuse Aurora and Enhanced Magnetospheric Density Regions from Coordinated Observations of South Pole All-Sky Imager and THEMIS Spacecraft. 2013-01-01.
|
|
|