Probing Space Weather Events with the Cornell University Portable Radar Imager (CUPRI)

该项目将对VHF康奈尔大学便携式雷达成像仪（CUPRI）进行升级和持续的科学研究，该仪器将从波多黎各搬迁到纽约伊萨卡的康奈尔大学。主要的科学重点是高纬度E区等离子体的不稳定性，这将通过CUPRI观测到的雷达回波进行研究。回声的来源仍然是一个有争议的话题；直到最近，人们还认为这些不规则现象是在强烈的高能粒子沉淀过程中产生的。然而，人们提出了两种新的机制。第一个涉及与风暴增强密度（SED）结构相关的陡峭等离子体密度梯度产生的不稳定性。从热带到等离子体顶以外的区域都观察到了SED特征。在适当的电场条件下，SEDs可能会导致等离子体变得不稳定，从而产生增强雷达反向散射所需的小规模结构。另外，可能还有另一种驱动等离子体不稳定性的机制：温度梯度不稳定性已被观察到在沃洛普斯岛的超级雷达上产生HF散射。这些空间天气事件可能导致通信和导航系统的退化，因为主要的不稳定性级联到较小的尺度长度，产生散射和相应的多径干扰。除了研究干扰回波的起源，该项目还将探索其他三个科学问题：(1)由强烈的高能粒子降水产生的极光事件，就像CUPRI之前在可见极光弧的极地边缘观察到的那样，与SED结构有关，还是与SED结构不同？(2)在重大空间天气事件中，CUPRI获得的图像是否与总电子含量的扰动相关？(3)在Jicamarca雷达观测站观测到的磁向角的测量是否能更多地了解极光等离子体物理？(4)引起Wallops岛SuperDARN雷达观测到的部分高频散射的温度梯度不稳定是否在伊萨卡岛观测到的甚高频散射中起作用？CUPRI系统的计划升级包括：(1)部署额外的天线和接收器，以实现回波的三维成像以及回波的磁场向长角灵敏度测量；(2)用数字接收机代替模拟接收机，提高对不同天线数据的质量控制；(3)网络化的数据采集系统提供广泛的访问，包括学生访问，实时和处理过的数据产品；(4)创建大型网络数据库。该项目更广泛的影响包括为研究生和本科生提供开发、部署、操作和维护现代雷达设备的广泛实践经验，以及数据采集、分析和解释的机会。东道机构已表现出坚定的承诺，将代表性不足的群体包括在其研究活动中，特别是妇女和西班牙裔，预计这将在本项目下继续进行。

This project will undertake an upgrade to and continued science investigations with the VHF Cornell University Portable Radar Imager (CUPRI) which will be relocated to Cornell University in Ithaca, NY from Puerto Rico. The primary science focus is high latitude E region plasma instabilities which will be studied through observations of the radar echoes observed by CUPRI. The origin of the echoes remains a subject of debate; until recently, the irregularities were believed to be created during intense energetic particle precipitation. However, two new mechanisms have been proposed. The first involves the generation of instabilities by the steep plasma density gradients associated with storm-enhanced density (SED) structures. The SED features have been observed from the tropics to well beyond the plasmapause. Given the right electric field conditions, the SEDs may cause the plasma to go unstable, creating the small-scale structures required to enhance radar backscatter. Alternatively, there may be a second mechanism responsible for driving plasma instabilities: a temperature gradient instability that has been observed to produce HF scattering over the SuperDARN radar at Wallops Island. These space weather events can result in degraded communication and navigation systems as the primary instabilities cascade to smaller scale lengths, producing scatter with consequential multi-path interference. In addition to investigating the origin of the perturbed echoes, the project will explore three other science questions: (1) do auroral events created by intense energetic particle precipitation, like those previously observed by CUPRI along the poleward edge of visible auroral arcs, relate to, or are they distinguished from, SED structures? (2) will images obtained by CUPRI be correlated with perturbations in total electron content during significant space weather events? (3) can more be learned about auroral plasma physics from measurements of magnetic aspect angles, as has been observed at Jicamarca Radar Observatory? (4) does the temperature gradient instability that causes some of the HF scattering observed over the SuperDARN radar at Wallops Island play a role in VHF scattering observed from Ithaca? The planned upgrades to the CUPRI system include (1) deploying additional antennae and receivers to enable 3-D imaging of the echoes as well as measurements of the magnetic field aspect angle sensitivity of the echoes; (2) replacing analog receivers with digital receivers for improved quality control of the data from different antennae; (3) networking the data acquisition system to provide wide access, including student access, to real time and processed data products; and (4) creating a large networked database. The broader impacts of the project include the provision of extensive hands-on experience in developing, deploying, operating, and maintaining modern radar equipment to graduate and undergraduate students, as well as opportunities in data acquisition, analysis and interpretation. The host institution has demonstrated a strong commitment to including underrepresented groups in its research activity, particularly women and Hispanics, which is expected to continue under this project.