Current Conditions
24-Hour Trends
Solar Imagery & Aurora
Space Weather Alerts
Understanding the Numbers
Planetary K-Index (Kp)
What is it? The global geomagnetic storm index on a scale of 0-9.
For Ohio: You generally need a Kp of 6 or 7+ to see the aurora overhead. Kp 5 might produce a faint glow on the northern horizon.
Interplanetary Mag (Bz)
What is it? The north-south component of the solar wind's magnetic field, measured in nanotesla (nT).
The Goal: We want Negative (South) values. When Bz is negative, it connects with Earth's northward magnetic field, opening a pathway for solar energy to pour in. Values of -10 nT or lower are ideal for strong aurora.
Total Field (Bt)
What is it? The total strength of the interplanetary magnetic field, regardless of direction.
Context: Higher Bt means a stronger magnetic structure is hitting Earth. However, Bt alone doesn't cause aurora - you need negative Bz. Think of Bt as the "potential" and Bz as the "trigger."
Solar Wind Speed
What is it? How fast the solar particles are traveling.
Target: 500 km/s+. Faster wind hits Earth's magnetic field harder, creating brighter and more active displays.
Solar Wind Density
What is it? The concentration of particles in the solar wind.
Target: 10 p/cm³+. Higher density provides more "fuel" for the aurora, often triggering sudden outbursts.
Proton Events (10MeV Integral Flux)
What is it? A solar radiation storm caused by energetic protons reaching Earth.
Meaning: A warning like "exceeded 10000pfu" indicates a strong radiation storm (S3 level). While this can cause radio blackouts and affect satellites, it does not directly cause visual aurora in Ohio. However, it confirms the Sun is highly active.