SWPC has high-energy proton detectors on the GOES geostationary and NOAA polar-orbiting satellites. GOES 5-minute averaged integral proton flux (protons/cm2-s-sr), as measured by the SWPC primary GOES satellite for energy thresholds of >=10, >=50, and >=100 MeV, are provided. SWPC's proton event threshold is 10 protons/cm2-s-sr at >=10 MeV. GOES 5-minute averaged integral electron flux (electrons/cm2-s-sr). Measurements are made in three integral flux channels, one channel measuring all electrons with energies greater than 0.8 million electron Volts (MeV), one channel measuring all electrons with energies greater than 2 MeV, and one channel measuring all electrons with energies greater than 4 MeV. High-energy particles can reach Earth anywhere from 20 minutes to many hours following the initiating solar event. The particle energy spectrum and arrival time seen by satellites vary with the location and nature of the event on the solar disk.
The location of the NASA Advanced Composition Explorer (ACE) satellite at the L1 libration point between the Earth and the Sun, about 1,500,000 km forward of Earth, enables ACE to give up to one-hour advance warning of the arrival of damaging space weather events at Earth. The Solar Wind Electron Proton Alpha Monitor (SWEPAM) experiment provides the bulk solar wind observations for ACE.
