U.S.-Western Europe Cooperative Study of the Solar Wind Acceleration

该奖项支持W.A.Coles博士和加州大学圣地亚哥分校的两名研究生与挪威特罗姆索大学极光天文台的Ruth Esser和其他人、奥斯陆的Egil Leer、芬兰的Jussi Markkanen和德国林道Max Planck空气动力学研究所的Eockart Marsch合作进行空间物理研究。关于太阳风加速的许多领先的理论工作现在都在欧洲完成(特别是在挪威和这家德国研究所)。美国国际和平研究所和他的学生将从与这些领先的理论家直接合作的机会中受益匪浅。他们共同提议继续观测太阳风速，这些观测是在1990年夏天科尔斯博士休假时在斯堪的纳维亚半岛北部的欧洲非相干散射雷达设备(EISCAT)开始的。尽管观测时间有限，但1990年的数据首次实现了理论径向加速度剖面与实测值的定量比较。在接下来的几个夏天，他们将有更多的时间，这将使他们能够进行更多的观测，并大幅减少速度估计误差。这额外的观察时间确实需要更多的工作，而研究生以及几个欧洲合作者是其成功所必需的。这项提议的基本目的是提高对地球等离子体环境的了解。等离子体是由太阳辐射使大气电离而形成的。这个“电离层”与太阳的外层大气--“太阳风”--在一个叫做“磁层”的磁控区域内相互作用。拟议的合作研究旨在了解产生和加速太阳风的机制，导致太阳风速度的突然变化，这是造成电离层扰动的原因。这种干扰有许多重要的地球物理和实际症状，包括极光显示、高频通信中断、卫星通信链路衰落和长距离电力线中断。

This award supports Dr. W. A. Coles and two graduate students of the University of California at San Diego to collaborate in space physics research with Ruth Esser and others of the Auroral Observatory, University of Tromso, Norway, Egil Leer of Oslo, Jussi Markkanen of Finland, and Eckart Marsch of the Max Planck Institute for Aeronomy, Lindau, Germany. Much of the leading theoretical work on solar wind acceleration is now done in Europe (notably in Norway and at this German institute.) The U.S. PI and his students will benefit substantially from the opportunity to work directly with these leading theorists. Together they propose to continue observations of the solar wind velocity that were begun at the European Incoherent Scatter Radar Facility (EISCAT) in northern Scandinavia during the summer of 1990, when Dr. Coles was on sabbatical. Despite limits on the observing time, the 1990 data have permitted the first quantitative comparison of theoretical radial acceleration profiles with measurements. More time will be available to them in the coming few summers, which will enable them to make many more observations and drastically decrease the velocity estimation errors. This extra observing time does require much more work, and the graduate students as well as several European collaborators are necessary for its success. The basic aim of this proposal is to improve understanding of the earth's plasma environment. The plasma is formed by ionization of the atmosphere by solar radiation. This "ionosphere" interacts with the outer atmosphere of the sun, the "solar wind", in a magnetically controlled region called the "magnetosphere." The proposed collaborative research is directed at understanding the mechanisms which create and accelerate the solar wind, causing the sudden changes in its velocity which are responsible for ionospheric disturbances. Such disturbances have a number of important geophysical and practical symptoms, including auroral displays, high frequency communications blackouts, fading on satellite communication links, and long distance power line upsets.