Solar Sector Boundary Crossing Refresher


To those not inclined, enthusiastic gushing over Earth poised to cross a fold in the heliospheric current sheet on April 29/30 likely falls flat. That’s OK, twenty years ago I wouldn’t have understood a solar sector boundary crossing meant geomagnetic storm. Living in a state of gob smacked wonder over auroras, didn’t equate to comprehending how or why – shreds of murky high school science were of little use. Solar dynamic’s light didn’t flicker until the day I decided to figure it out from the perspective of one without a formal science education.

In October 2014 I wrote a post titled “Solar Sector Boundary Crossing”. If I do say so myself – a concise, accessible, easily understood window to the wonder of solar dynamics.

“Hang on for a lesson in solar dynamics – Earth is experiencing a solar sector boundary crossing. Let me explain….

The sun produces wind (currently 410.9 Km/second) that blasts across the cosmos. Just like Earth, our Sun has a magnetic field – known as the interplanetary magnetic field (IMF).  Whipped into a 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.

http://spaceweather.com/glossary/imf.html

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 – in the meantime, and barring the occasional high frequency radio disruption,  wonky GPS and cell phones, peppered with sudden power grid failure events – we’re treated to kick ass auroras.”

http://wso.stanford.edu/gifs/HCS.html

Magnetic Crochet


This is what happens when a solar eruption hurls energy our way at 11 million mph. Sunspot AR2017 erupted on March 29 with a healthy X-1 class flare – UV radiation ionized our upper atmosphere, resulting in a “ripple” in Earth’s magnetosphere. Known as a “magnetic crochet”, the disturbance occurred as AR2017 strutted her stuff –  geo-magnetic hiccups usually come knocking a few days after a flare – simultaneous “events” are rare.

For a short time radio signals were lost as static assaulted short wave operators.

Courtesy NASA’s Solar Dynamics Observatory – a video of AR2017 in action….

spaceweather.com

http://spaceweather.com/

AR2017 appears to have gotten it off her chest – simmering down with only a 55% chance of M and 20% chance of powerful X class activity in the next 24 hours. Dodging yet another cosmic EMP unscathed.

Scientists at Berkley have just released findings of a global “near miss” on July 23, 2012. A series of immense solar flares unleashed enough energy to rival the Carrington Event of 1859. Had the storm erupted 9 days earlier, our planet would have been in the cross hairs – global power grid failures, trillions of dollars in economic repercussions with an estimate of 4 – 10 years to recover.

http://www.universityherald.com/articles/8229/20140319/giant-solar-superstorm-narrowly-missed-earth-2-years-ago-electrical-damage-would-have-been-catastrophic.htm