SKY · SPACE WEATHER
The aurora isn't weather in the sky — it's weather in space. Four live numbers tell you whether the engine behind it is running: the Kp index, the solar wind's speed and density, the all-important magnetic-field Bz, and the power being poured into each polar atmosphere right now. Here they are, fused into one honest read.
Geomagnetic activity is low, the solar wind is near its background pace and the field is mostly northward. The aurora is confined to the polar regions tonight. Conditions can change within hours when a fresh stream or a flare’s ejecta arrives, so it is worth checking back.
Fused from the Kp index, DSCOVR solar wind and OVATION hemispheric power · NOAA SWPC.
Quiet
The total power being deposited into each polar atmosphere — the most direct gauge of how hard the aurora is glowing.
Kpis the headline 0–9 scale of how disturbed Earth's magnetic field is — the higher it climbs, the further from the poles the aurora reaches. But Kp is a three-hour average that lags reality, so the solar wind often tells you first. Watch Bz: when it turns negative (southward), the wind's magnetic field links to Earth's like two magnets snapping together and pours energy in — often more decisive than the Kp number itself. A fast wind with a northward Bz slides right past us.
Hemispheric power is the bottom line: the gigawatts actually being deposited into the polar atmosphere right now. Below ~20 GW the sky is quiet; 50 GW and up means a real, widespread glow. It updates every few minutes — the closest thing to a live thermometer for the aurora.
Every one of these numbers traces back to our star. Flares and coronal mass ejections launch the gusts; the Sun's rotation swings fast streams past Earth. The Sun canvas tracks the source.
SEE IT ON THE MAP
Watch the live auroral oval glow over the globe.