The Aurora is a result of collisions between particles in the earths athmosphere and charged particles from the suns atmosphere. When this happens we can see beautiful colors in the sky. Aurora can be seen in a lot of different colors, but the most common color is green. The Aurora borealis is also called northern lights.
|KP-INDEX (current)||G-SCALE (current)|
KP-INDEX is a system of measuring aurora strength. It goes from 0 to 9 (0 being very weak, 9 being a major geomagnetic storm with strong auroras visible).
So when you’re looking at the aurora forecast page, you want to look for high Kp numbers. The higher the better. Anything above (and including). Kp5 is classed as a geomagnetic storm.
To better understand the KP value and how it impacts visibility from your location you need to know your magnetic latitude. When you know the magnetic latitude you can use the table as a reference and determine if the northern lights are visible from your location or not.
|MAGNETIC LATITUDE||KP NUMBER|
It’s important to mention that a high KP value does not guarantee that the aurora is visible, however it is a great pointer to when it’s worth going out looking for it.
G-SCALE indicates the strength of the geomagnetic storm. I goes from 0 to 5. (0 being the weakest, 5 being an extreme geomagnetic storm).
G0 = Kp 4 and below = None
G1 = Kp 5 = Minor
G2 = Kp 6 = Moderate
G3 = Kp 7 = Strong
G4 = Kp 8 = Severe
G5 = Kp 9 = Extreme
Visit NOAA for more information about the G-scale.
|SOLAR WIND SPEED (current)||PROTON DENSITY (current)|
|384.4 km/sec||2.64 protons/cm3|
The solar wind is a stream of particles coming from the sun. The normal speed of the solar wind is about 300km/sec. When the windspeed reaches 500-800 km/s there is a higher likelyhood that a geomagnetic storm will occur.
|Bt (current)||Bz (current)|
Bt is indicating the strength of the interplanetary magnetic field(IMF). Bt is measured in nanoTesla (nT).
Bz plays the most important role when searching for the Aurora borealis. When the Bz is negative it means that it faces south. This is good for aurora viewing since it opens a “rift” for the solar wind to enter our magnetosphere.