Global Solar Wind Structure: Effects of Pickup Protons

全球太阳风结构：拾取质子的影响

• 批准号: 1004035
• 负责人: Arcadi Usmanov
• 金额: $ 31.1万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1004035&HistoricalAwards=false
• 关键词: Global; Solar; Wind; Structure; Effects

This award is made in response to a proposal submitted to and reviewed under the NSF/DOE Partnership in Basic Plasma Science and Engineering, joint solicitation NSF 09-596.This project will study the effects of interstellar pickup protons on the structure and dynamics of the outer heliosphere. This requires creating a three-dimensional magneto-hydrodynamic (MHD) solar wind model, by integrating a model that accounts for the pickup protons as a separate fluid, together with a one-dimensional turbulence transport model. The approach being adopted treats the solar wind plasma as a mixture of three comoving species - solar wind protons, electrons, and pickup protons - and includes separate mass and energy equations for the solar wind protons and electrons, and for the pickup protons. The final model will therefore account for the energy transfer from pickup protons to solar wind protons and for the plasma heating due to turbulent dissipation.Using the tilted-dipole approximation or representative solar magnetograms to prescribe boundary conditions at the coronal base will enable calculation of the global structure of the solar wind out to 100 astronomical units for all phases of solar activity, which can then be compared with observations from the Voyager spacecraft. The study will examine the heating and deceleration of the solar wind in the outer heliosphere, the role of pickup ions in the physical processes of the outer heliosphere, interactions between large and small scales, and the interplay between turbulence and the solar wind.The results of this research will be useful in studies of other astrophysical plasmas, in particular that of the interstellar medium, where thermal plasma and energetic particles are coupled via waves, as well as coronal mass ejections and cosmic ray propagation, and the solar wind interaction with the local interstellar medium. This work will use and further develop methods employed in industrial and engineering applications, establishing a strong cross-disciplinary interest.

该奖项是根据NSF/DOE基础等离子体科学与工程合作伙伴关系（联合招标NSF 09-596）提交并审查的提案作出的。该项目将研究星际拾取质子对外日球层结构和动力学的影响。这需要建立一个三维的磁流体动力学（MHD）太阳风模型，将一个将拾取质子作为独立流体的模型与一个一维湍流传输模型结合起来。采用的方法将太阳风等离子体视为三种共同运动的物质——太阳风质子、电子和拾取质子的混合物，并包括太阳风质子、电子和拾取质子的单独质量和能量方程。因此，最终的模型将解释从拾取质子到太阳风质子的能量转移，以及由于湍流耗散引起的等离子体加热。使用倾斜偶极近似或代表性太阳磁图来规定日冕基础的边界条件，将使太阳风的全球结构计算达到100天文单位，用于太阳活动的所有阶段，然后可以与旅行者号航天器的观测结果进行比较。该研究将考察太阳风在外日球层的加热和减速、吸收离子在外日球层物理过程中的作用、大尺度和小尺度的相互作用以及湍流与太阳风之间的相互作用。这项研究的结果将有助于其他天体物理等离子体的研究，特别是星际介质的研究，其中热等离子体和高能粒子通过波耦合，以及日冕物质抛射和宇宙射线传播，以及太阳风与当地星际介质的相互作用。这项工作将使用并进一步发展工业和工程应用中使用的方法，建立强大的跨学科兴趣。