Tonight into tomorrow, northern hemisphere sky watchers as far south as Iowa or Michigan to Washington State are on aurora alert. Auroras are caused by charged particles hitching a ride on solar wind, dark skies turn undulating curtains of mischievous colour when charged particles interact with molecules in our atmosphere. Usually, our magnetosphere acts as a planetary shield preventing geomagnetic interaction of charged particles. Every so often fast moving particles overwhelm our magnetic field, create an opening and light up night skies.
On May 12, a magnetic filament on the sun, seen here, became unstable and erupted. (NASA/SDO)
Since Monday, 3 additional solar eruptions sent fast moving charged particles our way. As a result the auroral oval (doughnut shaped ring around the pole where charged particles follow magnetic field lines, reason why far northern latitudes regularly witness geomagnetic storms), has shifted far to the south.
The northern lights as seen looking eastward from just east of Penzance, Sask., at 1:21 a.m. local time Tuesday morning. (Submitted by Notanee Bourassa)
The colour of that light depends on the kind of molecule and the altitude of the collision.
Green is the most common colour, produced when the particles collide with oxygen at an altitude of around 100 to 300 km. At about 300 to 400 km, the interaction with oxygen produces red. Pink occurs below 100 km when nitrogen atoms are struck.
Bottom line – Space Weather Prediction Centre forecasters say there’s a 75% chance of geomagnetic storm activity tonight. If your skies are clear, go outside. If she’s willing, Aurora will find you. Opportunities like this don’t come along every day.
To the delight of Aurora watchers Earth’s magnetic field vibrates in protest of unrelenting solar wind. An Earth facing hole of monstrous proportion opened on the Sun, belching winds of 600 Km/second (that’s almost 1.2 mph ) toward our planet. Defensive vibrating twists in Earth’s magnetic field ignited powerful geomagnetic storms.
Astronomers predict intense aurora activity to continue for several days.
The current auroral oval commands the Northern Hemisphere. Anyone living under the oval owes it to themselves to look up under clear dark skies. Those lucky enough to meet Aurora, embrace her stamp of indelible wonder. She’s waiting – all you have to do is find her.
Its been a while since space weather graced this blog, far too long if you ask me. With that in mind, ponder a Sunday night space weather update.
As I write solar wind blows at 354.8 km/second, 1,967 potentially hazardous asteroids are identified within 100 LD (lunar distance) from our planet and 2 observable fireballs have been recorded in the past 24 hours. Despite a lull in solar activity courtesy cyclical expectations of solar minimum, a behemoth Earth facing hole in the Sun’s surface catapults solar wind in our direction. Contact with Earth’s magnetic field is anticipated on February 19 or 20th. Aurora watchers can expect geomagnetic storms.
Few people know what space weather is, let alone grasp how it impacts life on Earth. If you were a passenger on NetJets flight 795 from White Plains to Burbank last week, you received a radiation dose of x 68.4 that of radiation exposure at sea level. Space weather is real and it matters. Happy Sunday.
SDO (Solar Dynamics Observatory) changed how we ponder our Sun. Launched on February 11, 2010, SDO became NASA’s first solar observatory. No larger than a minivan, purposeful and dedicated, SDO’s singular objective is to understand how solar activity impacts Earth. Instruments measure the Sun’s interior, magnetic field and plasma of the solar corona simultaneously – one mission, to understand space weather in relation to Earth and near-Earth space.
Space weather refers to the effects of solar wind on Earth’s magnetosphere, ionosphere and thermosphere. Conditions attributed to constant flows, punctuated by violent eruptions of solar plasma – charged particles, flung outwards from the Sun at speeds up to 1 million mph. Auroras, mesmerizing spectacles driven by clashes with solar plasma appear innocent enough – space weather has far greater ramifications.
Solar wind driven plasma is responsible for bending or obliterating radio waves, disrupting navigation systems, forcing airplanes to change course, decayed orbits of satellites, temporarily knocking out cell phone service and complete failure of power grids.During an intense geomagnetic storm in October of 2003, 46 0f 70 spacecraft failures were attributed to space weather. In March 1989, 3 minutes after impact of a severe solar storm, Quebec’s power grid was annihilated for 9 hours.
Over the next few weeks I’ll dissect space weather into digestible bites. Meanwhile, take a moment to witness one of SDO’s greatest gifts –
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.
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.
Massive sunspot AR 1785 – eleven times the diameter of earth – now faces our planet with potential for some nasty flares. Space weather forecasters at NOAA predict a 55% chance of M-class and 10% X-class for today.
Luckily earth has the magnetosphere which deflects solar wind and concentrates solar energy at the magnetic pole. Scientists have known for a long time the magnetosphere wasn’t perfect; just as the ozone layer develops “holes”, our magnetic shield is prone to “cracks”. Anyone lucky enough to see an aurora has witnessed the power of electrically charged solar winds.
In 1961 scientist Jim Dungey theorized these cracks occurred when the solar energy arrived packing a magnetic field that travelled in the opposite direction from our magnetic field. We now know these cracks can remain open for hours, allowing billions of electrically charged particles to light up the sky. Severe solar storms can wipe out satellites, communication, and power.
AR 1785 will most likely blast tons of plasma into space before fading away. Geomagnetic storms will rage – airplanes might change course to avoid radiation, auroras will dazzle, and few will be the wiser. I don’t lose sleep over space weather, I just wish more people understood the implications of a direct hit through an unlucky crack that could plunge us into darkness for months.
Photo by Taichi Nakamura of Dunedin New Zealand – southern hemisphere auroras when earth passed through a region of southward magnetic field, opening a crack in the magnetosphere on July 6.
The solar winds are currently kicking up quite a fuss. As someone who pays attention to these things – trust me when I say that’s pretty fast. Solar winds cut loose when coronal holes open up on the surface of the sun; unfathomable blasts explode from their bellies. At the moment reported to be 585 Km/sec.
This got me pondering – how fast is that really? It translates to 1,308,607.73 MPH!