Collaborative Research: CEDAR--Studies of Radio-Wave Scatter and Dynamical Processes in the Polar Summer Mesopause Region

研究人员将研究来自极地中层顶的强雷达回波的形态和小尺度垂直结构。这些被称为极地中间层夏季回波（PMSE）的独特回波的可能产生机制尚未得到很好的理解，并且由于缺乏所需的分辨率，观测受到限制。频域干涉测量法（FDI）可以潜在地提供有关回波垂直结构的信息，但该技术仅在存在单层时有效。研究人员开发了一种改进的方法，称为距离成像（RIM）。在该技术中，使用了许多发射机频率并采用了复杂的重建方案来获得所需的垂直分辨率。RIM方法将应用于从挪威特罗姆瑟的高频雷达获得的数据。研究中间层化学和动力学对于理解中层大气的温度结构具有重要意义。大气中层温度是与全球变化有关的长期变化的敏感指标。

The investigators will study the morphology and small-scale vertical structure of intense radar echoes from the polar mesopause. Possible generation mechanisms for these unique echoes, called polar mesospheric summer echoes (PMSE), are not well understood, and observations have been limited by the lack of needed resolution. Frequency domain interferometry (FDI) measurements can potentially provide information about the vertical structure of the echoes, but the technique only works when a single layer is present. The investigators have developed a modified approach called Range Imaging (RIM). In this technique, numerous transmitter frequencies are used and sophisticated reconstruction schemes are employed to obtain the desired vertical resolution. The RIM approach will be applied to data obtained from a very high frequency radar in Tromso, Norway. Studying mesospheric chemistry and dynamics is important for understanding the temperature structure of the middle atmosphere. Middle atmosphere temperature is a sensitive indicator of long-term changes associated with global change.