第十七期：What Controls the Global Morphology of Planetary Aurora?

讲座信息

讲座题目：What Controls the Global Morphology of Planetary Aurora?

讲座嘉宾：张彬铮 （香港大学理学院地球科学系）

时间：9月19日下午4点

地点：北航沙河主楼D座10层东

讲座摘要

Planetary magnetic fields control energetic particles in their space environments and guide particles to polar atmospheres to produce stunning auroral forms. As revealed by spacecraft measurements, the pathways of energetic particles to these planetary polar atmospheres are diverse, suggesting different coupling processes between their ionospheres and magnetospheres. These planets all have dipole-dominated magnetic fields, rotate in the same direction and are blown by solar wind, but what controls the global-scale patterns of energy dissipation, remains unknown. Based on three-dimensional magnetohydrodynamics calculations, we reveal that the competition between planet-driven plasma rotation and solar wind-driven flow convection determines the structure of global auroral morphologies. This unified theoretical framework can reproduce polar aurora from the Earth-type to Jupiter-type, via transition states that are strikingly consistent with the highly variable aurora patterns at Saturn. This generalised description of fundamental magnetospheric physics, proposed here and validated by decades-long observations, is applicable to exoplanetary systems.   

嘉宾介绍

张彬铮，香港大学理学院地球科学系助理教授，分别于浙江大学和达特茅斯学院获得工程科学本科和博士学位。2012-2015年在达特茅斯学院担任讲师与研究科学家，2016-2018年在美国国家大气研究中心(NCAR)开展独立博士后研究，2018年至今受聘香港大学地球科学系，主要从事MHD数值算法、空间天气大型建模以及行星磁层物理研究，在Science，Science Advances，APJ，GRL等杂志发表高水平SCI文章60余篇，多次担任美国自然科学基金委和美国宇航局项目通讯和会评专家， 2018年获得香港研究资助局杰出青年项目资助，2019年获国家自然科学基金委优秀青年科学项目（港澳）资助，美国国家大气研究中心McQueen Fellow。2022年起担任AGU Advances杂志编辑。