Lower and Middle Atmospheric Dynamics Using Interferometric Techniques

9402021 Palmer 空间和频域干涉测量 (SI/FDI) 技术的知识已经发展到能够获得真正科学成果的程度。 使用这些相对较新的技术为科学家提供了研究大气的额外观测结果。 该项目的第一阶段是使用内布拉斯加大学林肯分校最近购买的 915 MHz 雷达来研究行星边界层 (PBL)。 我们建议修改雷达，以便可以进行 FDI。 主要目标是研究大平原地区存在的低空急流对重力波传播的影响。 拟议的研究还扩展到对流层/平流层区域，PI 对改进观测方法感兴趣。 尽管在 VHF 波长下“校正”垂直速度的想法于 1985 年提出，但最近在多个波长下的测量对这一想法产生了怀疑。 PI 打算使用日本的 MU 雷达设施来调查该问题，那里有一个 VHF 干涉测量系统和一个 UHF 边界层雷达。 喷射流对折射层倾斜的影响也将使用 SI 技术进行研究。 已知等熵表面在喷射流峰值上方和下方的倾斜度会反转。 日本冬季有极强的急流，建议进行与研究急流直接相关的测量。 将利用格陵兰岛的 Sondre Stromfjord 雷达、日本的 MU 雷达和内布拉斯加州改进的 915 MHz 雷达，研究 FDI 技术对波长的依赖性。 FDI 技术可以提供湍流层垂直延伸的估计，这可能依赖于雷达波长。 使用这三个波长的观察应该可以阐明这个问题。

9402021 Palmer Knowledge of spatial and frequency domain interferometric (SI/FDI) techniques has progressed to a point where real scientific gains are being obtained. Using these relatively new techniques has provided the scientist with additional observations to investigate the atmosphere. The first phase of the project is the study of the planetary boundary layer (PBL) using a recently acquired 915 MHz radar at the University of Nebraska-Lincoln. We propose to modify the radar so that FDI can be performed. The main goal is to study the effect on gravity wave propagation of low- level jets, which exist in the Great Plains region. The proposed research also extends into the tropo/stratospheric regions, where the PIs are interested in refining the observational methods. Although the idea of "corrected" vertical velocities at VHF wave- lengths was introduced in 1985, recent measurements at multiple wavelengths has cast doubt on this idea. The PIs intend to investigate the problem using the MU radar facility in Japan, where there is a VHF interferometric system along with a UHF boundary layer radar. The effect of the jet stream on refractivity layer tilting will also be investigated using SI techniques. Isentropic surface are known to reverse in tilt above and below a jet stream peak. Japan has an extremely strong jet in the winter and it is proposed to make measurements directly related to studying the jet stream. Using the Sondre Stromfjord radar in Greenland, the MU radar in Japan, and the modified 915 MHz radar in Nebraska, the dependence of FDI techniques on wavelength will be investigated. The FDI techniques can provide an estimate of the vertical extend of turbulent layers, which may have a dependence on radar wavelength. Observations using these three wavelengths should elucidate this problem.