IRFP: Jupiter's Magnetosphere-Ionosphere System

国际研究奖学金计划使美国科学家和工程师能够在国外进行9至24个月的研究。该计划的奖项提供了联合研究的机会，以及使用国外独特或互补的设施，专业知识和实验条件。该奖项将支持博士24个月的研究奖学金。Ray将与英国伦敦的伦敦大学学院的NicholasLeos博士一起工作。 磁制动是星星将角动量释放给周围等离子体并自旋下降的过程，是太阳系形成的一个重要过程。木星与其周围等离子体盘的相互作用是这种相互作用的局部模拟。到目前为止，角动量传输的磁层-电离层耦合模型还无法将木星磁层等离子体（径向质量传输率和角速度分布）的现场测量与木星极光发射的观测相协调-这是这种耦合的一个明亮的标志。然而，以前的模型简化了电离层或磁层的处理，忽略了场向势允许的差分旋转，从而不能充分耦合热层和磁层流动。本研究将科罗拉多大学磁层角动量传输模型与伦敦大学学院木星电离层模型相结合，建立木星M-I耦合的第一个综合系统模型，该模型以同样复杂的方式处理大气层和磁层，并研究场向势如何影响母体的大气特性，从而影响角动量的净传输。通过改变行星质量、磁场强度和旋转速率，这项研究还将量化早期恒星的磁制动，并将其应用于太阳系外的形成。这项工作将在PI和伦敦大学学院的研究小组之间建立新的国际合作。 它将有助于了解木星和早期恒星的磁层-电离层-热层耦合系统，该系统在高层大气学、磁层物理学和太阳系形成等领域具有跨学科应用。

The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twenty-four month research fellowship by Dr. Licia C. Ray to work with Dr. Nicholas Achilleos at University College London in London, United Kingdom. Magnetic braking, the process by which a star sheds angular momentum to its surrounding plasma and spins down, is an important process in solar system formation. Jupiter's interaction with its surrounding plasma disc is a local analog for this interaction. Thus far, magnetosphere-ionosphere (M-I) coupling models of angular momentum transport have not been able to reconcile in situ measurements of Jupiter's magnetospheric plasma (radial mass transport rates and angular velocity profiles) with observations of Jupiter's auroral emission - a bright signature of this coupling. However, previous models simplified the treatment of either the ionosphere or the magnetosphere, inadequately coupling the thermospheric and magnetospheric flows by neglecting the differential rotation allowed by field-aligned potentials.This research merges the University of Colorado magnetospheric model of angular momentum transfer with the University College London Jovian Ionosphere Model, building the first comprehensive system model of Jupiter's M-I coupling which treats the atmosphere and magnetosphere with equal sophistication and investigates how field-aligned potentials affect the atmospheric properties of the parent bodies and thus the net transport of angular momentum. By varying the planetary mass, magnetic field strength, and rotation rate this research will also quantify magnetic braking for early stars with applications to extra-solar system formation.This work will develop new international collaborations between the PI and the research group at University College London. It will contribute to the understanding of the coupled magnetosphere-ionosphere-thermosphere system of Jupiter and of early stars, which has inter-disciplinary applications to the fields of aeronomy, magnetospheric physics, and solar system formation.