Studies of the Solar Wind Near the Sun

太阳附近太阳风的研究

• 批准号: 9008608
• 负责人: William Coles
• 金额: $ 20万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-06-01 至 1992-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9008608&HistoricalAwards=false
• 关键词: Studies; Solar; Wind; Near; Sun

The solar wind plasma within 20 Ro will be studied using a variety of radio propagation techniques. This will permit estimation of the spatial spectrum of density fluctuations, the mean flow velocity, its random component and the orientation of the magnetic field. These measurements will be compared with optical data, such as white light coronograph, magnetograph, and emission line observations. The basic objectives will be to learn more about the mechanism of coronal heating and the flow of energy near the critical point, and to study the coronal origin of large scale structures such as fast streams. Within 20 Ro earlier observations have shown a rapid increase in random velocity, excess power in density fluctuations on scales of 10 to 300 km, and density fluctuations which become highly isotropic. This study will measure the acceleration of the particles through the sonic point using multiple antenna intensity scintillations. The spatial anisotropy as a function of spatial scale will be measured by comparing angular scattering (measured at the VLA) with phase scintillation (measured with the VLBA). The intensity scintillations will be analyzed to learn the origin of the random velocity component. Finally, observations within 20 Ro can be compared with surface measurements more accurately than those further from the sun because the mapping distance is small and stream-stream interactions are much less important. A study will be made to determine the difference in the flow field between regions of different magnetic geometry.

20 Ro以内的太阳风等离子体将使用一个 各种无线电传播技术。 这将允许 密度涨落空间谱的估计 平均流速，其随机分量和方向 磁场这些测量结果将与 光学数据，如白色光日冕仪、磁记录仪和 发射谱线观测基本目标是学习 更多关于日冕加热和气流的机制 临界点附近的能量，并研究日冕起源 大规模的结构，如快速流。 在20 Ro以内 早期的观察表明， 速度，密度波动的过剩功率， 300公里，密度波动变得高度各向同性。 这项研究将测量粒子的加速度， 使用多个天线强度放大器的声波点。 作为空间尺度的函数的空间各向异性将是 通过比较角散射（在VLA测量） 相位闪烁（用VLBA测量）。强度 将分析这些事件以了解随机事件的起源 速度分量最后，20 Ro以内的观测值可以 与表面测量相比， 离太阳更远，因为映射距离小， 流与流之间的相互作用就不那么重要了。一项研究将 以确定流场的差异， 不同磁性几何形状的区域。