Plasma Irregularity Sources Associated with Charged Dust in the Polar Summer Mesosphere

对极地中间层夏季回波的解释已成为近地空间科学的核心挑战之一。这些雷达回波通常与高空夜光云（nlc）一起观测到，夜光云由带电尘埃粒子组成。由于ncs可以提供地球上全球气候变化的证据，并且是近地空间环境演变和动态的指标，因此定量理解pmse与ncs之间的关系也成为一个前沿问题。pmse被认为是由NLC源层中的小尺度电子密度不规则产生的。最近同时进行的探空火箭和雷达测量提供了迄今为止nlc内部等离子体结构及其与pmse关系的最完整图像。这些测量提供了强有力的证据，证明在带电尘埃云和背景中间层等离子体之间的边界层中，等离子体的不规则性也被观察到增强。要求提供资金，以便在定量了解据信产生pmse的电子密度不规则性的来源方面取得重要和实质性的进展。与最近的实验证据一致，将开发一个新的模型，将NLC边界层视为PMSE产生的主要来源区域。这项研究将提供一种新的方法和途径，以获得对NLC边界层在产生pmse中的重要性的基本见解。拟议的活动将通过在主要研究者所在机构建立基础设施和学术部门之间的合作而产生广泛的影响。该活动还将维持首席研究员与政府研究实验室之间的长期合作。这一活动将促进大气科学和国际等离子体界之间的合作。最后，少数PI和研究生教育将得到这项工作的支持。

The explanation of Polar Mesospheric Summer Echoes (PMSEs) has become one of the central challenges in near earth space science. These radar echoes are often observed in conjunction with high altitude noctilucent clouds (NLCs), which consist of charged dust particles. Since NLCs may provide evidence of global climate change on earth and are an indicator of the evolution and dynamics of the near earth space environment, a quantitative understanding of the relationship between PMSEs and NLCs has also become a forefront issue. PMSEs are believed to be produced by small-scale electron density irregularities in the NLC source layer. Recent simultaneous sounding rocket and radar measurements have produced the most complete picture to date of the plasma configuration inside NLCs and the relationship to PMSEs. These measurements provide strong evidence that PMSEs are enhanced in the boundary layer between the charged dust cloud and the background mesospheric plasma where plasma irregularities are also observed to be enhanced. Funding is requested to make an important and substantial advance in the quantitative understanding of the source of electron density irregularities believed to produce PMSEs. Consistent with the recent experimental evidence, a new model will be developed to consider the NLC boundary layer as a primary source region for PMSE generation. This investigation will provide a new methodology and approach to gaining fundamental insight into the importance of NLC boundary layers in producing PMSEs.The proposed activity will have broad impact by establishing infrastructure and collaboration between academic departments at the principal investigator's home institution. The activity will also sustain long term collaboration between the principal investigator and government research laboratories. The activity will allow collaborations to be furthered between the atmospheric science and international plasma communities. Finally, a minority PI and graduate student education will be supported by this work.