CEDAR Postdoc: Determination of Charged Dust Characteristics in the Earth's Mesosphere Utilizing Radio Wave Modification

该项目是对极地中层夏季回波进行加热实验，作为表征这一现象所涉及的带电尘埃层的一种手段。PMSE是在夏季极地中间层观测到的异常雷达回波;这些回波与带电尘埃或气溶胶粒子有关，由于可能与全球变化有关，目前引起了相当大的兴趣。回声的确切产生机制是目前争论的一个话题，需要关于带电尘埃粒子密度和半径以及带电机制的信息。这些特性已经很难探索到目前为止，但最近的努力，积极修改PMSE与无线电波，以获得诊断信息似乎很有希望：重要的带电尘埃特性信息，如尘埃密度和尘埃半径，可以获得一旦一个坚定的理论解释的时间行为的不规则性在加热过程中被理解。该项目的目标是通过执行两项任务来发展这一能力：（1）开发和利用无线电波加热修正PMSE的新的计算和分析模型;（2）参加定于2007年和2008年夏季进行的欧洲非相干散射修正实验。如果EISCAT的结果由于高工作频率而受到影响，该项目可能会要求在高频活动极光研究计划（HAARP）或高功率极光刺激（HIPAS）进行后续加热实验。将开发的模型将包括扩散效应，更准确的充电模型，等离子体温度的演变，功能没有发现在早期的模型，并将用于模拟PMSE的时间行为在加热事件与不同的灰尘参数。观测数据将与模型结果进行比较，以改进模型并开发新的诊断能力。我们的目标是提供一个坚实的理论基础，解释在加热周期的时间电子密度行为，并最终开发诊断预测实验测量。更广泛的影响包括支持一个新的博士后学者在耦合，能量学和动力学的大气区域（CEDAR）计划，而实验将最终提供新的诊断工具，为未来的PMSE修改和PMSE观测。研究结果对极地中层云和平流层云的研究有一定的参考价值。

This project is to perform heating experiments on polar mesosphere summer echoes (PMSEs) as a means to characterize the charged dust layer involved in this phenomenon. As the name states, PMSEs are anomalous radar echoes observed in the summer polar mesosphere; the echoes are associated with charged dust or aerosol particles and are of considerable current interest because of a possible connection with global change. The exact generation mechanism for the echoes is a current topic of debate, and information on the charged dust particle density and radius as well as on the charging mechanism is needed. These characteristics have been difficult to explore thus far but recent efforts to actively modify PMSE with radio waves to obtain diagnostic information appears promising: important charged dust characteristic information, like dust density and dust radius can be obtained once a firm theoretical interpretation of the temporal behavior of the irregularities during heating is understood. This project's goal is to develop this capability by performing two tasks: (1) develop and utilize new computational and analytical models of PMSE modification by radio wave heating; and (2) participate in the European Incoherent Scatter (EISCAT) modification experiments scheduled for the summers of 2007 and 2008. The project may request follow-on heating experiments at the High Frequency Active Auroral Research Program (HAARP) or the High Power Auroral Stimulation (HIPAS) if the EISCAT results are compromised due to high operating frequencies. The models to be developed will incorporate diffusion effects, more accurate charging models, and plasma temperature evolution, features not found in earlier models, and will be used to simulate the temporal behavior of PMSEs during heating episodes with varying dust parameters. The observational data will be compared with the model results to refine the model and to develop new diagnostic capabilities. The goal is to provide a firm theoretical foundation for interpreting the temporal electron density behavior during the heating cycle and ultimately developing diagnostic predictions for experimental measurements. The broader impacts include the support of a new postdoctoral scholar in the Coupling, Energetics and Dynamics of Atmospheric Regions (CEDAR) program while the experiment will ultimately provide new diagnostic instruments for future PMSE modification and PMSE observation. The research results are likely to be beneficial for investigations of polar mesospheric and noctilucent clouds.