September 2nd marks a historic 150th anniversary. On this day in 1859 miners in Virginia woke at 3 am thinking glowing skies signaled sunrise. From the North Pole to Cuba, Hawaii, most of Mexico, parts of Central America and Colombia, China and Japan, brilliant auroras delivered a electromagnetic circus. All across Europe and North America telegraph wires sparked, stations caught fire, some operators reported sending and receiving messages even after disconnecting power lines.
150 years ago British astronomer Richard Carrington witnessed a unprecedented solar flare – today we know it as the Carrington Event. A similar event today would devastate life as we know it. Ponder weeks, months, possibly years without electricity, internet, ATMs, GPS, power to pump water and fuel, air, road or rail travel. Space weather is real and it matters.
On September 3rd space weather predicts a solar sector boundary crossing.
Our sun produces wind (currently 316.9 Km/second) blasts across the cosmos. Just like Earth, the Sun has a magnetic field – known as the interplanetary magnetic field (IMF). Whipped into spiral rotation, wind driven IMF rotates in one direction. It divides into spiral sections pointing to and away from the sun along the ecliptic plane ( a 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 (scientific term, southward Bz) the two fields link causing 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).
It takes 3 or 4 days for magnetism to sort itself out – during that time expect occasional high frequency radio wave disruption, wonky GPS and cell phone service peppered with sudden power grid failure events. On the upside, we’re treated to kick ass auroras.
Space weather really does matter.