CEDAR: Impacts of Lower Atmosphere Forcing on the Mesosphere-lower Thermosphere and Ionosphere During September Equinox Transition

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项目编号	1552153
	CEDAR: Impacts of Lower Atmosphere Forcing on the Mesosphere-lower Thermosphere and Ionosphere During September Equinox Transition
	Nicholas Pedatella
主持机构	University Corporation For Atmospheric Res
项目开始年	2016
	2016-06-15
项目结束日期	2019-05-31
资助机构	US-NSF
项目类别	Continuing grant
项目经费	194169(USD)
国家	美国
语种	英语
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.
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文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/69660
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Nicholas Pedatella.CEDAR: Impacts of Lower Atmosphere Forcing on the Mesosphere-lower Thermosphere and Ionosphere During September Equinox Transition.2016.