U.S.-Czech Space Research on Propagation and Non-Linear Properties of Plasma Waves

这个由爱荷华大学的Donald A. Gurnett和布拉格查尔斯大学的Ondrej Santolik合作的美国-捷克研究项目的目标是将最先进的分析技术应用于空间等离子体的波测量。欧洲航天局最近发射的星团任务由四个相同的航天器组成，这些航天器配备了用于测量地球磁层和邻近区域的等离子体波、场和粒子的仪器。由此产生的高质量波浪测量需要先进的方法来解释和分析潜在的物理过程。为了分析这个新的Cluster数据和来自两个早期任务（Polar和Cassini）的数据，美国-捷克团队将采用各种方法，如波分布函数、高阶光谱和多点/多尺度测量的相关方法。他们的研究计划以美国在波浪仪器方面的优势和捷克在卫星数据分析和波浪观测解释方面的专业知识为基础。研究人员打算共同确定：1)在极光区和弓形激波附近的非线性现象的性质；2)在磁赤道附近和极光区观察到的哨声模式等离子体波的来源和传播；3)产生这些等离子体波的波粒相互作用。研究结果将有助于更好地理解地球周围发生的基本物理过程，其中许多与太阳-地球联系有关，其中波起着基本作用。此外，当计划更复杂的调查时，这些发现应该对后续的多航天器任务有用，这些调查旨在回答理论家和建模者提出的关于恒星和地球等离子体波环境的问题。该项目通过使美国和中欧的专家能够在共同感兴趣和能力强的领域结合互补的人才和共享研究资源，实现了推进科学知识的计划目标。更广泛的影响包括，通过在合作机构工作，将美国和捷克学生引入国际空间研究界，并直接参与该项目的先进数据分析和建模技术。

The goal of this U.S.-Czech research project between Donald A. Gurnett of the University of Iowa and Ondrej Santolik of Charles University in Prague is to apply state- of-the-art analysis techniques to wave measurements in space plasmas. The European Space Agency's recently launched Cluster mission consists of four identical spacecraft equipped with instruments designed for measurements of plasma waves, fields and particles in Earth's magnetosphere and adjacent regions. The resulting high-quality wave measurements require advanced methods for interpretation and analysis of the underlying physical processes. To analyze this new Cluster data and data from two earlier missions (Polar and Cassini), the US-Czech team will employ various methods such as wave distribution functions, higher order spectra, and correlative methods for multi-point/multi-scale measurements. Their research plan builds upon U.S. strengths in wave instrumentation and Czech expertise in satellite data analysis and interpretation of wave observations. Together the researchers intend to determine the: 1) properties of nonlinear phenomena in the auroral region and near the bow shock, 2) sources and propagation of plasma waves in the whistler mode observed near the magnetic equator and in the auroral region, and 3) wave particle interactions responsible for generation of these plasma waves. Results should lead to a better understanding of basic physical processes occurring around Earth, many of them related to the Sun-Earth connection in which waves play a fundamental role. Furthermore, findings should be useful to follow-on multi-spacecraft missions when planning more sophisticated investigations designed to answer questions posed by theorists and modelers about stellar and terrestrial plasma wave environments. This project fulfills the program objective of advancing scientific knowledge by enabling experts in the United States and Central Europe to combine complementary talents and share research resources in areas of strong mutual interest and competence. Broader impacts include the introduction of U.S. and Czech students to the international space research community through work at partner institutions and direct involvement in the project's advanced data analysis and modeling techniques.