Aurora Season


Don’t despair over fall dropping summer leaves, autumn is aurora season in the northern hemisphere. Auroras dance in the wake of geomagnetic storms – the product of blustery solar winds vibrating Earth’s magnetic field. Consider our magnetic field (magnetosphere) a protective barrier of protons and electrons. When uppity solar winds smack Earth’s magnetic bubble dislodged particles shower the atmosphere with auroras iconic glow. Spring and fall have twice the geomagnetic storms as summer and winter, the product of interplanetary tilt near the equinoxes.

Interplanetary tilt – think of our sun as an enormous magnet, all planets in our solar system orbit within the Sun’s magnetosphere. At magnetopause, the point at which the farthest reach of Earth’s magnetosphere battles solar forces, our magnetic field points north. No harm no foul unless the Sun’s magnetic field tilts south, a defining characteristic occurring near the equinoxes. When north and south facing magnetic fields link up, Earth’s magnetic field is partially cancelled at point of contact, with wild abandon displaced particles dance the northern lights.

Science calls the north/south facing magnetic portal Bz. Negative south pointing Bz’s allow solar wind energy to penetrate Earth’s magnetic fortress, positive north pointing Bz’s slam the door shut. Bz’s ebb and flow in response to Earth’s wobbly axis. Every spring and fall Earth’s axis careens obligingly towards gates of the Bz portal – aurora season has arrived.

http://news.nationalgeographic.com/news/2011/04/pictures/110408-new-aurora-pictures-deep-sky-northern-lights-space/

Autumn is Aurora Season

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

Solar Sector Boundary Crossing


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.

Aurora Alert Tonight


Ponder Earth’s magnetic field as a shield protecting us from harmful cosmic radiation. Known as “geomagnetic” because it starts at our solid iron outer core, (miles below the surface) and reaches to the outer atmosphere. (creating a magnetosphere, the point in space beyond the ionosphere where charged particles protect us from solar wind and radiation). Without it – our ozone layer would wither, and we would succumb to ultraviolet radiation. In other words, life could not exist.

When strong solar winds impact the magnetosphere, they “distort” our magnetic field creating “openings” – the near side to the sun being “compressed” and far side of the planetary field is bulged outward.

  1. As the charged particles of solar winds and flares hit the Earth’s magnetic field, they travel along the field lines.
  2. Some particles get deflected around the Earth, while others interact with the magnetic field lines, causing currents of charged particles within the magnetic fields to travel toward both poles — this is why there are simultaneous auroras in both hemispheres. (These currents are called Birkeland currents after Kristian Birkeland, the Norwegian physicist who discovered them — see sidebar.)
  3. When an electric charge cuts across a magnetic field it generates an electric current (see How Electricity Works). As these currents descend into the atmosphere along the field lines, they pick up more energy.
  4. When they hit the ionosphere region of the Earth’s upper atmosphere, they collide with ions of oxygen and nitrogen.
  5. The particles impact the oxygen and nitrogen ions and transfer their energy to these ions.
  6. The absorption of energy by oxygen and nitrogen ions causes electrons within them to become “excited” and move from low-energy to high-energy orbitals (see How Atoms Work).
  7. When the excited ions relax, the electrons in the oxygen and nitrogen atoms return to their original orbitals. In the process, they re-radiate the energy in the form of light. This light makes up the aurora, and the different colors come from light radiated from different ions.

http://science.howstuffworks.com/nature/climate-weather/atmospheric/aurora2.htm

Two recent solar events – CME’s (coronal mass ejection) are poised to deliver Aurora magic in regions unaccustomed to their magnificence. Solar wind from the first eruption have arrived, with stronger consequences from the second ejection expected in the next few hours. What this means is Auroras could be visible far below normal latitudes. Some scientists project as far south as Mexico.

If you feel so inclined – go outside, cast your gaze northward, and watch for tell tale green ripples across the sky. Best time to view is between midnight and dawn – obviously clear skies away from city lights are advisable.

http://earthsky.org/space/significant-auroras-predicted-for-tonight-and-tomorrow?utm_source=EarthSky+News&utm_campaign=e4e54e437a-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-e4e54e437a-393970565

Taken a few hours ago from the International Space Station

 

 

 

 

 

 

Attention Northern Hemisphere Sky Watchers


This is not a warning, hysterical plea to take cover or recruiting post for the tin foil hat club – simply a heads up for Northern hemisphere sky watchers. Sunspot AR1865 sent an M1 class flare our way, it should reach earth’s magnetic field this evening. Not powerful enough to cause a bad day – even though it was earth directed – the magic is expected to unfold in spectacular auroras.

Those who have witnessed Aurora’s spell understand her soul restoring powers. Those who haven’t can only hope that one day she will allow you to witness her dance across the northern sky. If you happen to find yourself in a dark place, away from city lights; gaze upwards tonight – if you’re lucky, Aurora will dance for you.

NASA – AR1865

80/60 With Another X-Class for Show


AR1748 is one pesky sunspot; still beating its chest, and threatening to show us who’s boss. With odds of eruptions now up to 80% for M-class and 60% for X in the next 24 hours – 1748 unleashed another X class flare today – in case the three X flares of 1.7, 2.8, and 3.2 the previous day hadn’t made us stand up and take notice. As AR1748 turns towards earth, today’s X-1 is expected to deliver a little slap – most likely in the form of geo-magnetic disturbances responsible for crazy beautiful auroras. Ar1748 has produced more X-class flares in the last few days than all other sunspots this year combined.

NASA Solar Dynamics Observatory – photo of AR 1748 taken on May 16

http://sdo.gsfc.nasa.gov/

Pole Reversal


Historical and scientific records indicate many earth shattering events are long overdue. The “big one”, referring to a mega earthquake in the pacific north west, the Yellowstone super volcano, and apparently – a magnetic pole reversal.

I always believed theories of pole reversal lived only on the pages of books. Discovering this event is not only probable, but has happened in our history on more than one occasion, gave birth to this ponder.

http://www.cosmosmagazine.com/news/earths-poles-long-overdue-reversal/

Andrew Biggin from the University of the Netherlands in Utrecht, analyzed rock to determine how they were magnetized at formation. This allowed him to pin point the location of the magnetic pole at the time. His research showed a reversal every 400,00 years or so; the last one taking place about 800,000 years ago. He suggests that a pattern of  weakening in the earth’s magnetic field takes place for around 2000 years prior to the complete reversal. Archaeological evidence indicates our magnetic field was considerably stronger in Roman times.

Pole reversal doesn’t happen overnight; overdue, in earth terms could be hundreds, thousands, or millions of years. Just one more reason to ponder our time on earth. One more reason to embrace each day, not sweating the little stuff.