| 项目编号: | 1552255
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| 项目名称: | Collaborative Research: CEDAR--Life Cycle of the Quasi Two-Day Wave in the Southern Hemisphere |
| 作者: | David Ortland
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| 承担单位: | NorthWest Research Associates, Incorporated
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| 批准年: | 2016
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| 开始日期: | 2016-03-15
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| 结束日期: | 2019-02-28
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| 资助金额: | 74874
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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: | research
; atmosphere
; quasi two-day wave
; wave coupling
; atmospheric wave activity
; year
; southern hemisphere region
; upper atmospheric research program
; wave structure
; large-scale wave structure
; qtdw wave phenomenology
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| 英文摘要: | The Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) program, a broad-based, community-guided, upper atmospheric research program, is aimed at understanding the behavior of atmospheric regions from the lower atmosphere upward through the ionized upper layers of the atmosphere. One of the major themes of this program is the measurement of the transfer of atmospheric wave activity from the lower atmosphere into the mesosphere and lower thermosphere, which overlaps the lower ionosphere. An important dynamical phenomenon associated with this wave coupling is called the quasi two-day wave (QTDW), which is a large-scale wave structure seen in the middle atmosphere winds and temperatures that is particularly pronounced within the southern hemisphere region with a spatial extent over many thousands of km. The lifetime of this structure varies between one and two weeks with a rapid growth, evolution, and decay profile that is not understood. The research of this award would utilize simultaneous data from two NASA satellites to follow the spatial progression of this structure with high temporal resolution. The 10 years extent of the database will allow this phenomenon to be intercompared from year to year and for the two periods of solar maximum and solar minimum. This research would determine through the application of a theoretical primitive equation model what might be the predominant excitation source generating this wave structure. Two possible candidates would be investigated. One (baroclinic instability) is the development of a dynamical instability mechanism energized by the poleward edge of the stratospheric jet stream. The other (inertial instability) is an instability process energized near the geographic equator as a result of the very weak magnitude of the Coriolis force. The broader impact of this award is the improvement of our overall understanding of fundamental MLT dynamics. A graduate student would receive half-time support.
The proposed activity will directly address questions regarding the coupling between atmospheric height regions, and possible energetics feedbacks between the QTDW wave phenomenology and the zonal mean circulation. The QTDW structure will be holistically investigated from the generation region into the 110 km region. Momentum and energy exchange across the stratopause and mesopause boundaries will be examined. The study will encompass a decade of observations, 2002-present, which will allow study of contrasting years, e.g., the possible influence of stratospheric warmings. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/92684
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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: | |
David Ortland. Collaborative Research: CEDAR--Life Cycle of the Quasi Two-Day Wave in the Southern Hemisphere. 2016-01-01.
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