Alternate Definitions for Kp Index

The Kp index indicates the magnitude of geomagnetic disturbance on a 0-9 scale, with zero being very quiet and 9 indicating a major geomagnetic storm. The index has a three-hour cadence. Higher values of Kp are associated with geomagnetic storming, the appearance of auroral lights at lower than normal latitudes, and stronger linkages between Earth’s upper atmosphere and magnetosphere. See also the "Kp Indicies" Cygnet wiki page.