A Severe G4 Geomagnetic Storm is expected to lash at earth around 03:00 — 09:00 UTC Saturday morning (11 p.m. EDT Friday night to 5 a.m. EDT Saturday morning).
A series of strong solar flares and Coronal Mass Ejections took place Wednesday and Thursday, directed towards Earth. These originated from a large and magnetically complex sunspot cluster (NOAA region 3664). Additional solar eruptions could cause geomagnetic storm conditions to persist through the weekend.
There is potential for disruption of communications, the electric power grid, navigation, radio and satellite operations.
And there will be bright auroras, potentially as far south as Alabama!
CME
Coronal Mass Ejection (CMEs) are explosions of plasma and magnetic fields from the sun’s corona. They travel at high speeds away from the Sun at speeds ranging from slower than 250 km/s to as fast as 3,000 km/s and reach Earth’s orbit in 1 to 2 days. They cause geomagnetic storms when they strike Earth.
Geomagnetic storms can impact infrastructure in near-Earth orbit and on Earth’s surface, potentially disrupting communications, the electric power grid, navigation, radio and satellite operations.
Space Weather Tonight
The CMEs ejected by the Sun this week are headed for earth, as shown in the stills from the animation at NOAA. The main merged CME should arrive around 02:00 UTC Saturday morning (10 p.m. EDT Friday night), which means good Aurora viewing for those in North America.
Here is the Aurora forecast for tonight for North America.
Peak Geomagnetic Activity is expected between 06:00 and 09:00 UTC with a Kp Index of 8.33 (G4 on the G-Scale).
From www.swpc.noaa.gov/… — "The K-index quantifies disturbances in the horizontal component of earth's magnetic field with an integer in the range 0-9 with 1 being calm and 5 or more indicating a geomagnetic storm. The label 'K' comes from the German word 'Kennziffer' meaning 'characteristic digit.' The K-index was introduced by Julius Bartels in 1938."
Past Severe Solar Storms
Here is a list of major solar storms over the past century.
The ones in 1989 and 2003 are well studied and are known to have caused major disruptions and damage to power systems and orbiting satellites.
The Halloween solar storms of 2003 were caused by a series of solar flares and CMEs that peaked around Oct 28–29 at G5 levels and caused wide ranging impacts — www.ncei.noaa.gov/… -
- Power outages in Sweden
- ~59% of the Earth and Space science missions were impacted.
- Temporary failure of the SOHO satellite
- Damage to the Advanced Composition Explorer (ACE)
- Loss of the ADEOS-2 satellite
- A majority of LEO satellites were temporarily “lost” as their orbits were altered
- Loss of the Martian Radiation Environment Experiment aboard NASA's Mars Odyssey orbiter.
- Communication problems for airline flights flying over the North Pole
- Full communications blackout for over five days in Antarctic science groups
Modern day power grids and satellites are better designed to handle solar storms and space radiation, so the impact is likely to be lot less with tonight’s G4-level storm.
The Sun
To get a feel for what transpires on the surface of the calm-looking Sun, let’s take a look at this fascinating time-lapse video from NASA. The video was created using images taken by NASA’s Solar Dynamics Observatory SDO,.
It is beautiful and yet frightening. But remember it is powered by nuclear fusion occurring deep in the core of the Sun, which provides the energy needed to start and sustain life in our solar system. Earth's magnetic field helps deflect dangerous flares and energetic particles away from earth and our atmosphere, while allowing the good stuff (heat, light) to reach earth and to sustain life.
Updates
The solar storm seems to have arrived earlier than predicted and has raised the Kp index to above 8 in the G4 range already. Aurora sightings are being reported from Europe. Lot more to come in N. America.
The Kp index has been at 9 (G5) for the past several hours. The Kp index stops at 9.
Epilogue
Let’s hope that this solar storm produces some wonderful auroras, but not much more. Let’s hope there will be little damage to power systems and satellites. Given the much higher number of satellites in Low Earth Orbit today compared to 1989 and 2003, the potential for damage, disruption and lost satellites is probably high.
Let’s hope some of us get to take some stunning photographs of the Aurora Borealis and post them tomorrow.