Masa amaran anggaran

Kaedah pengiraan

Lead time is estimated with: Distance ÷ Solar Wind Speed

• The average distance from the L1 point to Earth is about 1.5 million kilometres.
• Solar wind speed is measured in kilometres per second (km/s).
• The result is converted into minutes for easier interpretation.

Cara mentafsir

• Faster solar wind means shorter warning time.
• Slower solar wind means longer warning time.
• This is not the exact aurora arrival time, only the estimated lag from L1 data to Earth.

Mengapa penting

Lead time helps aurora watchers judge how quickly changes in solar wind speed, density or magnetic field might begin to affect Earth.

Data satelit di L1

The Solar Wind Speed, Proton Density and Magnetic Field cards all use measurements from satellites near the L1 Lagrange point, so the lead time applies directly to those values.