Investigation of the Mesospheric Chemistry and Dynamics Using the Arecibo Radar Facility

在所有尚未解决的中层大气问题中，中上层(80-95公里)出现的问题似乎比其他任何地区都多。在这里积累问题的一个一般原因是，用于模拟该区域下方区域的辐射、化学和动力学方程都包含在中间层上层无效的简化。这意味着，该区域的理论和模型需要特别注意，而不是它上面或下面的区域通常需要的关注。这一区域不仅很难建模，而且也很难进行实验研究。这一区域太高，不能用飞机或气球进入，也太低，不能进行卫星现场测量。显然，发展可靠的遥感技术对研究这一大气区域很重要。在开发雷达技术以研究包括电离层D区在内的中间层上层化学方面，马修斯教授正在开展一项开创性的工作，国际电离层协会正在就这一建议开展工作。利用美国国家科学基金会在波多黎各的阿雷西博和波士顿地区的米尔斯通山运营的大型非相干雷达设施，马修斯教授已经能够为D区化学和相关动力学的重要研究生成有价值的数据集。这项提议描述了一个研究项目，目的是扩大观测范围，分析数据，并开展关于中间层离子化学模型以及零星电离层的形成和维持的理论工作。包括电子和离子浓度在内的实验结果将被用作对理论模型的约束。此外，还将进一步完善雷达散射理论和应用。

Of all the unsolved problems of the middle atmosphere, more seem to occur in the upper mesosphere (80-95km) than in any other region. One general reason for the accumulation of problems here is that radiative, chemical and dynamical equations used to model the regions below this region all contain simplifications that are invalid in the upper mesosphere. This implies that theories and modeling for this region require special attention beyond that usually required for the regions above or below it. Not only is this region difficult to model, but it is also difficult to investigate experimentally. This region is too high for access with airplanes or balloons and too low for satellite in situ measurements. Clearly, the development of reliable sensing techniques is important to the study of this region of the atmosphere. A pioneering effort in the development of radar techniques for the study of the chemistry of the upper mesosphere which includes the ionospheric D region is being carried out by Prof. Mathews, the PI on this proposal. Using large incoherent radar facilities operated by NSF at Arecibo in Puerto Rico and Millstone Hill in the Boston area, Prof. Mathews has been able to generate a valuable data set for the important study of D-region chemistry and the associated dynamics. THis proposal describes a research project to extend the observations, analyze the data, and carry out theoretical work on the modelling of mesospheric ion chemistry and the formation and maintenance of the sporadic ionization layers. The experiment results which include the electron and ion concentrations will be used as constraints on the theoretical models. also, work will be done on further refinement of the radar scattering theory and utilization.