| 项目编号: | 1552153
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| 项目名称: | CEDAR: Impacts of Lower Atmosphere Forcing on the Mesosphere-lower Thermosphere and Ionosphere During September Equinox Transition |
| 作者: | Nicholas Pedatella
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| 承担单位: | University Corporation For Atmospheric Res
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| 批准年: | 2016
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| 开始日期: | 2016-06-15
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| 结束日期: | 2019-05-31
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| 资助金额: | 194169
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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: | september equinox
; stratospheric wind
; ionosphere
; upper atmosphere dynamics
; result
; thermosphere temperature
; state-of-the-art whole atmosphere datum assimilation model
; plasma density
; comprehensive ionosphere
; lower-upper atmosphere coupling
; variability
; upper atmosphere variability
; atmosphere region
; ionosphere total electron content
; atmosphere wave
; investigation
; upper atmosphere region
; middle atmosphere region
; september equinoctial study
; data assimilation whole atmosphere model
; first whole atmosphere model
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| 英文摘要: | This award supports the investigation based upon the analysis of satellite data with plasma density, oxygen composition, and mesosphere lower thermosphere temperatures being the key parameters selected. The goal of this investigation is to understand how the short-term variability that is observed in the ionosphere total electron content (TEC) during the September equinox may be explained as a result of the wave coupling between the lower and upper atmosphere regions. These TEC variations can be characterized as ionospheric weather that occur as a result of several dissipative processes that are supported by the coupling of large scale lower atmosphere waves to the ionospheric plasma of the region between 100 to 350 km. The key idea that would be studied in this award is based upon the fact that the transmission of large scale waves upward from the lower atmosphere region maximizes during the equinoctial period. Normally, the stratospheric winds would block these waves from reaching such high heights. However, the September equinox is when the direction of stratospheric winds reverses direction being eastward during winter and westward during the summer. During the equinox, these stratospheric winds are weak and then transmission of the large scale waves through the middle atmosphere region becomes possible. The investigation will compare modeled results for the oxygen composition, temperature, and plasma densities in the region of 100 to 350 km computed for the September equinoctial study to the satellite measurements of these quantities for this same period. An undergraduate student will be involved in the proposed research activities through the Significant Opportunities in Atmospheric Research and Science (SOARS) program. The involvement of a SOARS student will serve to enhance participation of historically under-represented groups in the atmospheric sciences. The research will further benefit society through an improved understanding of short-term, day-to-day, variability in the ionosphere. Understanding this variability is critical due to the impact of the ionosphere on communication and navigation signals.
The modeling research would use numerical simulations of the plasma densities using a newly-developed, state-of-the-art whole atmosphere data assimilation model (WACCMX). Incorporation of data assimilation in WACCMX will represent the first whole atmosphere model with a comprehensive ionosphere and thermosphere to include the data assimilation capability, enabling new insights into lower-upper atmosphere coupling during specific events. By employing a data assimilation whole atmosphere model, the numerical simulations can be directly compared with the observations. This capability will be used to diagnose the mechanisms responsible for the observed variability. The realization of the proposal objectives will result in an overall improved understanding of the upper atmosphere variability that occurs using the September equinox transition as a representative simplified case study drawn from the overall range of upper atmosphere dynamics. This simplification is a result of the weakness of stratospheric winds during the reversal period. The elimination of the need to know in detail the stratospheric winds thus enhances the ability to assess and measure the modeling capability to simulate the other physical processes ongoing in upper atmosphere dynamics. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/92039
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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: | |
Nicholas Pedatella. CEDAR: Impacts of Lower Atmosphere Forcing on the Mesosphere-lower Thermosphere and Ionosphere During September Equinox Transition. 2016-01-01.
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