Natural phenomenon needn’t be mysterious. Ponder Aurora Borealis, arguably one of nature’s greatest phenomenon, least mysterious spectacles. Aurora are offspring of space weather, nothing mysterious about that. On May 11, 2020 Earth is expected to cross a fold in the heliospheric current sheet. In less mysterious language – disruption of interplanetary space separating opposing magnetic polarities of Earth and Sun, briefly over riding Earth’s magnetic field, inviting solar energy to temporarily dazzle sky watchers with aurora majesty – consider yourself schooled in solar sector boundary crossing, a space weather basic.
Solar wind is the source of space weather. Just like Earth, the Sun has a magnetic field known as interplanetary magnetic field (IMF). Whipped into spiral rotation, wind driven IMF rotates in one direction dividing into spiral sections pointing to and away from the sun along an ecliptic plane ( direct line between Earth and the Sun). The edge of this swirling mass has a surface separating polarities of planetary and solar magnetism called the heliosphere current sheet.
Earth’s magnetic field points north at the magnetopause (the point of contact between our magnetosphere and the IMF). If the IMF happens to point south at contact the field link causes partial cancellation of Earth’s magnetic field – in other words, opening a temporary door for solar energy to enter our atmosphere. Welcome solar sector boundary crossing – a phenomenon born of high solar wind and coronal mass ejections (CME’s – aka solar flares).
Enough talk, time for dazzling aurora timelapse courtesy Adrian Mauduit at Night Lights Films –
This GIF explained the Aurora Borealis finally to me. It’s sort of obvious to me now.
Fantastic graphic. Thanks.