How Strong Are The Northern Lights Right Now?
If you are only looking at the Kp Index, you are looking at old data. To know exactly how strong the aurora is right now, you need to look at the magnetic field data coming from satellites 1 million miles away.
Specifically, we look at the Bz (Interplanetary Magnetic Field). Think of this as a “Magnetic Door.”
- Bz is Negative (South): The door is OPEN. Solar wind pours in. Aurora is strong.
- Bz is Positive (North): The door is LOCKED. Solar wind bounces off. Aurora is weak.
Below is our Pro-Level Magnetic Dashboard showing the live status of this door.
🧲 Live Magnetic Gate Status
Real-time DSCOVR Satellite Data
-3.0 nT
South (Open)
501 km/s
Fast
0.2 p/cm³
Normal
6.8 nT
Total Field
Extreme Storm
How To Read This Data (Like a Pro)
1. The Bz (Direction) – The Most Important Number
This is the “Latch” on the door.
– If you see a Negative Number (e.g., -10 nT), get your camera ready. The further negative it goes, the stronger the storm.
– If you see a Positive Number (e.g., +10 nT), the aurora will likely fade away, even if the Kp index is high.
2. The Bt (Strength)
This is how hard the wind is pushing on the door. A high Bt (over 15 nT) combined with a negative Bz creates the most violent and colorful displays.
3. Speed & Density
This is the fuel. High speed (>500 km/s) creates purple/pink colors. High density (>10 p/cm³) creates brightness.
Frequently Asked Questions
Q: Can the Bz change quickly?
A: Yes. It can flip from North to South in seconds. This is why the aurora often “dances” or explodes suddenly, then fades away just as fast.
Q: What is a “Substorm”?
A: When the Bz stays South (Negative) for a long time, energy builds up in Earth’s magnetic tail. Eventually, it snaps back like a rubber band, releasing massive energy. This is a substorm, and it creates the brightest, fastest-moving auroras.
