Aurora Info

[James Willinghan]

For those interested with the chance for Aurora tonight. Here is the latest message from SpaceWeatherLive.

“The X5.1 coronal mass ejection has just arrived at the Sun-Earth L1 point. ACE detected the impact a few minutes ago. Solar wind data at ACE is unreliable due to the ongoing S2 solar radation storm. Ignore the low speed! The Bt jumped to 35nT with a northward Bz component at the time of writing.”

For understanding Bz  here is a better write up:

“ The north-south direction of the interplanetary magnetic field (Bz) is the most important ingredient for auroral activity. When the north-south direction (Bz) of the the interplanetary magnetic field is orientated southward, it will connect with Earth’s magnetosphere which points northward. Think of the ordinary bar magnets that you have at home. Two opposite poles attract each other! A (strong) southward Bz can create havoc with Earth’s magnetic field, disrupting the magnetosphere and allowing particles to rain down into our atmosphere along Earth’s magnetic field lines. When these particles collide with the oxygen and nitrogen atoms that make up our atmosphere, it causes them to glow and emit light which we see as aurora.

For a geomagnetic storm to develop it is vital that the direction of the interplanetary magnetic field (Bz) turns southward. Continues values of -10nT and lower are good indicators that a geomagnetic storm could develop but the lower this value goes the better it is for auroral activity. Only during extreme events with high solar wind speeds it is possible for a geomagnetic storm (Kp5 or higher) to develop with a northward Bz.”

Another factor is the DST index and Solar Wind data. DST index measures the strength of the ring current around the Earth and is a key indicator of geomagnetic storm severity. Lower (more negative) Dst values indicate more energy stored in the magnetosphere, which is good for aurora viewing. Here is the current chart from SpaceWeatherLive. 

Remember, things can change. Just keep watching the data as it comes in from the Solar spacecraft ACE and DISCOVER which are sitting between Earth and the Sun and will know what’s happening first. 

Here is a link to the data being returned from the orbiters….

https://www.swpc.noaa.gov/products/real-time-solar-wind

Hope this helps and doesn’t confuse anyone too much.

James

Sent from my iPad

[James Willinghan]

Data from the orbiters looks correct. Spaceweather.com is reporting a downgrade to their forecast. Things could still change!

THE THIRD CME HAS ARRIVED (UPDATED):  The highly-anticipated 3rd CME has arrived. It struck Earth's magnetic field at approximately 1917 UTC on Nov. 12th. Our first impression of the impact: It was not strong enough to cause a repeat of last night's extreme aurora display. We are downgrading our storm forecast from category G4 (severe) to  G2/G3 (moderate/strong).

Sent from my iPad

On Nov 12, 2025, at 3:18 PM, James Willinghan <jpwil...@gmail.com> wrote:

For those interested with the chance for Aurora tonight. Here is the latest message from SpaceWeatherLive.

“The X5.1 coronal mass ejection has just arrived at the Sun-Earth L1 point. ACE detected the impact a few minutes ago. Solar wind data at ACE is unreliable due to the ongoing S2 solar radation storm. Ignore the low speed! The Bt jumped to 35nT with a northward Bz component at the time of writing.”

For understanding Bz  here is a better write up:

“ The north-south direction of the interplanetary magnetic field (Bz) is the most important ingredient for auroral activity. When the north-south direction (Bz) of the the interplanetary magnetic field is orientated southward, it will connect with Earth’s magnetosphere which points northward. Think of the ordinary bar magnets that you have at home. Two opposite poles attract each other! A (strong) southward Bz can create havoc with Earth’s magnetic field, disrupting the magnetosphere and allowing particles to rain down into our atmosphere along Earth’s magnetic field lines. When these particles collide with the oxygen and nitrogen atoms that make up our atmosphere, it causes them to glow and emit light which we see as aurora.

For a geomagnetic storm to develop it is vital that the direction of the interplanetary magnetic field (Bz) turns southward. Continues values of -10nT and lower are good indicators that a geomagnetic storm could develop but the lower this value goes the better it is for auroral activity. Only during extreme events with high solar wind speeds it is possible for a geomagnetic storm (Kp5 or higher) to develop with a northward Bz.”

Another factor is the DST index and Solar Wind data. DST index measures the strength of the ring current around the Earth and is a key indicator of geomagnetic storm severity. Lower (more negative) Dst values indicate more energy stored in the magnetosphere, which is good for aurora viewing. Here is the current chart from SpaceWeatherLive. 

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[James Stuby]

I'm out with a wide angle camera shooting 4 sec exposures every 6 sec.  Bz seems to be oscillating + and - now.

Jim Stuby

Sent from my Galaxy

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