MAGNETOSPHERE
Live Data
Kp Index (real-time)
A complete list of real-time data links is located in the Space Weather Resources section.
From Observatories: Kp Index
The Kp index is the easiest way to find out if there has been a disturbance in the Earth's magnetic field and how severe the disturbance was. The Kp index combines the disturbances in the Earth's magnetic field measured at 9 separate observatories in North America. The Kp plot for the several days after the solar storms of May 27, 2003 is shown below.
The horizontal axis is Universal Time (UT) . Each bar is for 3-hour intervals. The vertical axis shows the Kp index from 0 to 9. Kp values below 4 indicates little disturbance. The bars are green when the Kp is less than 4, yellow when the Kp equals 4, and red when the Kp is greater than 4. The red bars indicate a storm warning. Values greater than 7 indicate a large disturbance. The disturbance at the end of May 29 and the early hours of May 30 was significant and long lasting. From the Kp you can predict how strong an aurora might be visible and how far from the poles the aurora might be seen.
Tools for Predicting Aurora
The Kp index can be used to predict where you might see an aurora. The higher the Kp number the stronger the disturbance. A large disturbance in the Earth's magnetic field is likely to produce strong aurora that extend further toward the equator. The map below shows the connection between Kp and the predicted southern edge of the aurora in North America. When the Kp equals 5, aurora could be expected south to the green line. With a Kp of 9 auroras could be expected south to the red line. In some cases when the Kp equaled 9 auroras were seen in Texas and Florida. Click the map below to launch the application.
The magnetic disturbance of May 29 and 30, 2003 had a Kp index of 8. The aurora was visible in Virginia.
- NASA Official: Dr. James Thieman
- Project Manager: Don Robinson-Boonstra
- Website Manager: Bryan Stephenson