FW: Topband: Three day forecast of the Planetary Kp Index now available online

Dave AA6YQ

Daily variability of HF propagation is caused in large part by solar energetic particle radiation carried by the solar wind,
especially during the four years closest to solar minimum when x-ray and proton radiation from solar flares are less frequent and
less intense.

The three-hourly Planetary Kp Index uses geomagnetic measurements from 13 observatories at mid-latitudes to indirectly measure solar
energetic particle radiation. The Planetary Kp Index is a proxy measurement of the energy input from the solar wind to Earth,
similar to the use of the 2800 MHz Solar Flux Index as a proxy for the Sun's ionizing ultraviolet radiation.

A three day -- updated every three hours -- forecast of the Planetary Kp Index is now available from the Helmholtz Centre Potsdam -
GFZ German Research Centre for Geosciences.