加拿大卡尔加里大学天文物理系主任David Knudsen教授报告会通知

Auroral arcs are the familiar curtains ofgreen or red light that extend from horizon to horizon in the polar sky. Their lower border is at an altitude ofonly 100 km, making them accessible to high-resolution measurements by both ground and space-based instruments. However, despite decades ofdetailed study, there remains no accepted theory of the generator that powers arcs, nor of the cause oftheir characteristic structure. Moreover, most popular explanations ofthe aurora are incorrect. For example, in general the aurora is NOT caused by solar wind electrons striking the upper atmosphere. This talk will address the gap between auroral observations and theories, and will include an overview ofrecent ground-based and in situ observations made by scientists at the University ofCalgary.